2003 Trans. Clunking

HELLO, IM NEW TO THIS. I JUST BOUGHT A USED 2003 CHEVY SILVERADO EXT. CAB SHORT BED Z71, WITH THE LS TRIM. IT HAD ABOUT 11,000 MILES ON IT WHEN I BOUGT IT A MONTH AGO. WELL FIRST I NOTICED THE TRANSMISSION CLUNKING BETWEEN 2 AND1 GEAR ON A DOWN SHIFT UPHILL. NOW I NOTICE A STUTTER BETWEEN 1 AND 2 GEAR WHEN I TAKE OFF. IT IS NOT ALL THE TIME. ALSO WHEN I HAVE MY CRUISE CONTROL ON. ON THE HIGHWAY, IT LIKES TO JUMP BACK AND FORTH GOING DOWN HILL. BUT WHEN I TAKE IT OUT OF CRUISE AND JUST HOLD STEADY AT SPEED, IT IS FINE. IF ANYONE HAS ANY INFO ON ANY OF THESE TOPICS PLEASE LET ME KNOW.

I have a 03 avalanche and I have similiar problems. I took it to the Dealer and I have no problems. I taled to a performance shop and they let mu use a Hypertech power programer for a week. Wow what a difference. It really smothed up the transmision.

Supposibly the reason people are haveing problems today is GM found that they get better life out of a transmission if it shifts down, istead of locking up the tourqe converter witch causing heat.

I have been in a few trucks and mine is "was" the worst.

With Hypertech it is like my 98' used to be.......................

Good luck

Learn to live with it or take a loss and buy the new 2004 Ford. You've bought a "Clunker."

I just today took my new 2003 "Clunkrolet" Silverado with 7000 miles on it in to the dealer for the second time for the infamous clunking problem. The first time they used some type of "magical special grease" which lasted about a week before the clunking returned. They told me it was the slip yoke banging and it was a normal noise. The standard response is it's "operating to the manufacturers specs, they all do that and it's normal." Normal my a$$. Fords and Dodges don't go clunking around the roads like my Silverado does. The dealer told me that's because they are designed differently. It's an obvious engineering problem. I read where one fix was a nickel plated slip yoke and I mentioned that to the service guy today and he said the 03's already had those on them. Well, then that wasn't a fix was it? I also read where they were replacing the drive shafts. Anyway, one way or another, I want the problem resolved. They told me they can't fix it because it's normal. I might look into the lemon law. That might be a start. Or maybe a complaint with the Feds. I know for sure I will be calling GM's complaint line.
We have been a GM family for 30 plus years. My wife drives a 2003 Buick and I've always been loyal to GM. But I swear that after paying $32,000 for a vehicle with such a glaring problem and getting an "it's normal" excuse from GM I will sell the "clunker" and go with the 2004 Ford truck ad you won't see another GM car in my driveway.
My advise to someone thinking about a Chevy/GMC truck is to think again.


Here's GM's Service Bulletin:

Driveline - Clunk Explanation
File In Section: 04 - Driveline Axle
Bulletin No.: 99-04-20-002A
Date: September, 2001
INFORMATION
Subject:
Driveline Clunk
Models:
2002 and Prior Light Duty Truck Models
This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 99-04-20-002 (Section 04 - Driveline/Axle).
Important: The condition described in this bulletin should not be confused with Driveline Stop Clunk, described in Corporate Bulletin Number 964101R (Chevrolet 92-265-7A, GMC Truck 91-4A-77, Oldsmobile 47-71-20A, GM of Canada 93-4A-100) or Bump/Clunk Upon Acceleration, described in Corporate Bulletin Number 99-04-21-004.
Some owners of light duty trucks equipped with automatic transmissions may comment that the vehicle exhibits a clunk noise when shifting between Park and Drive, Park and Reverse, or Drive and Reverse. Similarly, owners of vehicles equipped with automatic or manual transmissions may comment that the vehicle exhibits a clunk noise while driving when the accelerator is quickly depressed and then released.
Whenever there are two or more gears interacting with one another, there must be a certain amount of clearance between those gears in order for the gears to operate properly. This clearance or freeplay (also known as lash) can translate into a clunk noise whenever the gear is loaded and unloaded quickly, or whenever the direction of rotation is reversed. The more gears you have in a system, the more freeplay the total system will have.
The clunk noise that owners sometimes hear may be the result of a buildup of freeplay (lash) between the components in the driveline.
For example, the potential for a driveline clunk would be greater in a 4-wheel drive or all-wheel drive vehicle than a 2-wheel drive vehicle. This is because in addition to the freeplay from the rear axle gears, the universal joints, and the transmission (common to both vehicles), the 4-wheel drive transfer case gears (and their associated clearances) add additional freeplay to the driveline.
In service, dealers are discouraged from attempting to repair driveline clunk conditions for the following reasons:
Comments of driveline clunk are almost never the result of one individual component with excessive lash, but rather the result of the added affect of freeplay (or lash) present in all of the driveline components.
Because all of the components in the driveline have a certain amount of lash by design, changing driveline components may not result in a satisfactory lash reduction.
While some owners may find the clunk noise objectionable, this will not adversely affect durability or performance.

I have the same problem here. I just went through my first round at the dealership. They gave me the same run around as noted above. Have any of you gotten anyware since the last reply?

According to the service bulletin this is due to backlash in the drive train. I am not an expert on automatic transmissions, but to me it feels more like the transmission is shifting when the gears are not at a matched RPM, causing a horrific “clunk”.

As far as the cruise control, mine does the same thing. More annoying than anything else. I just tap the brake and use the throttle until I get to the bottom of the hill. I had a 93 chev pickup and didn't have this issue. Very disappointing to see we have step backwards in technology.
.

Well, Ryder, I don't know what we can do. I just got back from a short 350 mile trip and the clunking problem is becoming real loud and frequent. The truck actually shudders. And I'm really ticked off at GM. I was told by a friend who works for Chrysler's to ask to speak to a zone manager and then to his boss and up the ladder until I got some satisfaction. Well, I called the dealer yesterday and talked to a service advisor and asked him about how I go about speaking to a "zone manager" and he said they don't speak to the public. I then asked to speak to the service manager and he told me he was in a meeting and that he's call back. I'm still waiting......hmmmmmmm.

I called the GM complaint number and filed a complaint with them. I asked the person on the phone what happens next and she said "nothing". "We have it on file." I plan on filing a complaint with the Better Business Bureau's BBB Auto Line. (800) 955-5100 or online at www.dr.bbb.org/goauto. It probably won't help but I'm not laying down for GM or anybody else that sells me a defective product.

I also am going to write a letter to the President of GM and send a copy to my newspapers automotive section. I don't believe there's a fix for this problem because of GM's shoddy manufacturing or design of the gears that are causing the gear lash and they know it. They've sold thousands of these defective trucks and are now trying to cover their butts.

GM used to have a jingle on that went something like this:
"See the USA in your <Chevrolet> CLUNKROLET"

Dropped mine at the gmc delaer yesterday for the same thing. Sold me some $30 lube & we'll see what happens with it.

Hope it works Dakota. They used the special magical lube/grease on my mine the first time I took it in saying the slip yoke needed greased and was causing the clunking. It didn't work.

BTW, I just talked to the service manager and he told me that they were just a repair facility and had to go by what GM says and GM says there's nothing wrong with my Clunkrolet. He told me he'd drive my truck for a day and if the clunking was no different from any five other new trucks off the lot there would be nothing he could do. Sure he'll drive it because he knows they all clunk. He told me I couldn't talk to the zone manager and to call up the GM complaint line again and make another complaint. I've read on another site where GM is extended the warranties on the transmissions to 100,000 miles if you complain loud enough and contact the BBB Autoline. The service manager denied any knowledge of this. I'll calling the BBB right now.

"See The USA In Your Clunkrolet'

Took mine in with only 200 miles on it with same issue. They had a TSB out there to reprogram the Trans Control Module with new cals. It significantly reduced the clunks and slips but did not eliminate them. I think there's too much pep with this 5.3 to get a smooth shift.

Also, had my VIN fallen within a certain range the Service Manager said it would have needed some mechanical work that was specified on the TSB in addition to the reprogramming. Good Luck.

Thanks for the info GMT. I'll call the dealer tommorow and ask him about reprograming the trans module. Would you happen to know the bulletin number for that service?

Also I talked to a lawyer today and he stated I'd have to take the truck into the dealer's 2 more times for a total of 4 and then he would take my case under our state's lemon law.

ANd they had toprogram the ecm for a new shifting program & cost me 100.00 Woulndt that be covered somewhere if the last one was bad??

I did a bulletin search this morning and found a couple bulletins that MAY apply to the concern on your truck.
My recommendation is to take it back to the dealer and talk to the service manager and ask him to perform a bulletin search on your specific concern while you are standing there with him.
There are 2 bulletins for a 1-2 shudder on those trucks.
I had the 1-2 shudder on my 02 Sierra and I fixed it per the bulletin...Smooth as silk now
If you need more info feel free to PM me.

I have a '01 z71 ext cab with 30,000 miles on it. I just bought it used and I have the clunk in th rear end from park to reverse. Had it in for warantee and of course the same old answer "its normal". I like your info and the service bulletin you posted. Hopefully it is true that no damage or reliability issues will occur. My mechanic said too much play in the rear end so I took it to the dealer. Oh well, I may have my machanic take it apart to see what he thinks. I would rather pay him to fix it than go through the hassel and grief with the dealerships.

Cheers.

Learn to live with it or take a loss and buy the new 2004 Ford. You've bought a "Clunker."

I just today took my new 2003 "Clunkrolet" Silverado with 7000 miles on it in to the dealer for the second time for the infamous clunking problem. The first time they used some type of "magical special grease" which lasted about a week before the clunking returned. They told me it was the slip yoke banging and it was a normal noise. The standard response is it's "operating to the manufacturers specs, they all do that and it's normal." Normal my a$$. Fords and Dodges don't go clunking around the roads like my Silverado does. The dealer told me that's because they are designed differently. It's an obvious engineering problem. I read where one fix was a nickel plated slip yoke and I mentioned that to the service guy today and he said the 03's already had those on them. Well, then that wasn't a fix was it? I also read where they were replacing the drive shafts. Anyway, one way or another, I want the problem resolved. They told me they can't fix it because it's normal. I might look into the lemon law. That might be a start. Or maybe a complaint with the Feds. I know for sure I will be calling GM's complaint line.
We have been a GM family for 30 plus years. My wife drives a 2003 Buick and I've always been loyal to GM. But I swear that after paying $32,000 for a vehicle with such a glaring problem and getting an "it's normal" excuse from GM I will sell the "clunker" and go with the 2004 Ford truck ad you won't see another GM car in my driveway.
My advise to someone thinking about a Chevy/GMC truck is to think again.


Here's GM's Service Bulletin:

Driveline - Clunk Explanation
File In Section: 04 - Driveline Axle
Bulletin No.: 99-04-20-002A
Date: September, 2001
INFORMATION
Subject:
Driveline Clunk
Models:
2002 and Prior Light Duty Truck Models
This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 99-04-20-002 (Section 04 - Driveline/Axle).
Important: The condition described in this bulletin should not be confused with Driveline Stop Clunk, described in Corporate Bulletin Number 964101R (Chevrolet 92-265-7A, GMC Truck 91-4A-77, Oldsmobile 47-71-20A, GM of Canada 93-4A-100) or Bump/Clunk Upon Acceleration, described in Corporate Bulletin Number 99-04-21-004.
Some owners of light duty trucks equipped with automatic transmissions may comment that the vehicle exhibits a clunk noise when shifting between Park and Drive, Park and Reverse, or Drive and Reverse. Similarly, owners of vehicles equipped with automatic or manual transmissions may comment that the vehicle exhibits a clunk noise while driving when the accelerator is quickly depressed and then released.
Whenever there are two or more gears interacting with one another, there must be a certain amount of clearance between those gears in order for the gears to operate properly. This clearance or freeplay (also known as lash) can translate into a clunk noise whenever the gear is loaded and unloaded quickly, or whenever the direction of rotation is reversed. The more gears you have in a system, the more freeplay the total system will have.
The clunk noise that owners sometimes hear may be the result of a buildup of freeplay (lash) between the components in the driveline.
For example, the potential for a driveline clunk would be greater in a 4-wheel drive or all-wheel drive vehicle than a 2-wheel drive vehicle. This is because in addition to the freeplay from the rear axle gears, the universal joints, and the transmission (common to both vehicles), the 4-wheel drive transfer case gears (and their associated clearances) add additional freeplay to the driveline.
In service, dealers are discouraged from attempting to repair driveline clunk conditions for the following reasons:
Comments of driveline clunk are almost never the result of one individual component with excessive lash, but rather the result of the added affect of freeplay (or lash) present in all of the driveline components.
Because all of the components in the driveline have a certain amount of lash by design, changing driveline components may not result in a satisfactory lash reduction.
While some owners may find the clunk noise objectionable, this will not adversely affect durability or performance.

I have the clunk when shifting into reverse. Will there ever be a solution to this problem from GM????

silvered:

i have the exact same truck as you and i have also noticed the "bouncing" thing when going down hill in cruise control. the clunk noise is quite familiar to me now as well...and just as annoying.

naked avalanche:

tell us more about the programmer and how it helped smooth things out.

yeah, just letting yall know that i am having the same problem with my truck. at first i thought it was comming from the rear end but now im not sure. in my truck its the loudest when i am starting off from a dead stop but only if the vehicle has rolled back some, like on a small incline. the dealer told me it was the brakes and not to worry cause it dosent do it all the time. i guess we will just have to wait and see what gm decides to do about it. i hope that it does not affect durability. oh and i have 4500 miles on my truck and it has been doing it noticably since about 1000 miles.

bad bad bad

I'm having the same problems with clunking and a real bad chatter (like shaking the whole truck) especially when the driver side rear wheel broke on some leaves my truck chattered like crazy. Took it to the dealer and they said it was normal. I have read some of the complaints on here and it sounds like most of them are sounds from the tranmission but my sound is definately from the rear. I hear it also when i take off when shifts in between 1st and 2nd. I've taken it twice to the dealer and it only has 3800 miles on it. I also own a 1978 Chevy 1/2 ton that i plow with and it does not even make noises like that. After all these years you think that GM could have perfected something. I'm seriously looking at trading it in for a new Ford. And to think they soaked me for $$$$$ on and extended warranty in which i will fight to get back.

I did a bulletin search this morning and found a couple bulletins that MAY apply to the concern on your truck.
My recommendation is to take it back to the dealer and talk to the service manager and ask him to perform a bulletin search on your specific concern while you are standing there with him.
There are 2 bulletins for a 1-2 shudder on those trucks.
I had the 1-2 shudder on my 02 Sierra and I fixed it per the bulletin...Smooth as silk now
If you need more info feel free to PM me.
If you don't mind me asking, what're the issues regarding the shudder from 1st to 2nd? I ask because I think mine may have the same problem (only happens from 1-2), although it's not always extremely noticeable. I assume it's repaired under warranty, but is it a quick fix? If I'm unable to take my Silverado in soon is it going to be detrimental (I bought it used a couple months ago, it's at 31K miles)? Do you happen to have those service bulletins numbers that may be related to it so I can reference them? Thanks.

Hi guys,
My 2001 Z71 (26000 miles) has clunks in the driveline as well. Park to reverse, 1-2,2-3,2-1. The most annoying clunk I hate is the one when you go around a corner slow and then ease into the gas again. CLUNK!
I am told it is because of the auto-trac system.
I can believe that. I also believe there to be some engineering defect.
If you change your own oil, next time you are under your truck, grab the "small" driveshaft that comes out of the transfer case and turn it. You will hear the noise in the transfer case. GEEZ. I cannot believe the noise that mine is making is not causing damage.
I have taken it in 3 times. The service writer is a good friend of mine. I have a good friend that is an area GM rep for GMSPO. I have seen the bulletins and, apparently, there is nothing that can be done under the existing policies that GM.
Keep calling and writing GM, as the dealer apparently doesnt want anyone to buy another 1500 4x4. The service mgr wouldnt even take the time to talk with me at Young Chevrolet when I called. I even have a friend, who's wedding I was in, that is asst parts mgr there.
PS: They replaced the "yoke" already right after I bought it with 17k, and another dealer (where I used to work) replaced the rear diff later after my 2nd trip to a dealer. The rear diff replacement cleared up the park to drive clunk I had.

Let me know know if anyone hears anything good from GM.

I made the mistake of purchasing a new 2003 Chevy Silverado Ext Cab 4x4 automatic. After 6000 miles the drivetrain started clunking loudly any time I drive backwards (in reverse). The clunk does not occur when I shift to reverse but clunks when I accelarate faster than normal. The clunk also occurs frequently when I accelarate hard and then let off the throttle. It sometimes occurs on 1st to 2nd upshifts or downshifts.
I can feel the clunk in the floor and passengers ask me about it.

This problem takes all of the joy out of owning this new truck.
The dealer did the transmission reprogramming which did not correct the problem and they told me that I have to live with the problem.

DO NOT BUY A SILVERADO UNLESS YOU CAN LIVE WITH TYPE OF PROBLEM AND THE POOR CUSTOMER SERVICE FROM GM.

If anybody finds a soltuion to this problem, please post it here.

Thank you!

I have had my 03 Z71 for about a year now and have had in the shop numerous times for the clunking in the trans. It only does it on the upshift and downshift between 2 & 3. According to Chevrolet it is a characteristic problem. They refuse to fix the issue. They let you know about this little bulletin they have to read to find out what they will be doing. The bulletin reads:

During a 2-3 upshift, the 2-4 band is released and the 3-4 clutch is applied. The timing of this shift can cause a momentary torque reversal of the output shaft that results in a clunk noise. This same torque reversal can also occur on the 3-2 downshift when the 3-4 clutch is released and the 2-4 band applied. This condition may be worse on 4-wheel drive vehicle due to the additionmal tolerances in the transfer case.

This is a normal condition. No repairs should be attempted.

This applies to all light duty trucks 2003 and older.

You have to step up the HD truck to avoid this problem. You would think that they would fix the problem after all of these years, but as long as they are selling them there will be no fix. Chevy refuses to due anything about this problem.

geeez, im sure glad i dont have the newer style trucks. if i may add some of my own experiences though....

i used to own a 1985 chevy pickup, and i had the same exact "problems" you guys are explaining. the problem was backlash, a very excessive amount. it can be corrected by many things, because theres a lot that comes into play. first off, climb under your truck, and yank on the driveshafts. check to see whats turning. shims can be made for your rear diff that will reduce backlash. worn u-joints add to backlash. (my 85' went through a set every 2 years) your transfer case and tranny can also cause it, although i never ended up tearing into mine to see if i could eleiminate it. i drive that truck for 4 years, and never had a part failure due to that problem, other than the u-joints. my suggestion is to look into some of those things. maybe if enough people have the same adjustment that fixes the problem, GM will release a bulletin with that fix. just some thoughts. i hope you all get it figured out, i know how frustating dealers can be.

rob

I have a 2002 1500 HD (same tranny as Silverado 1500) that had similar transmission problems. It started at about 3000 miles but the dealer could not find any codes. The problem seemed to be slipping and not shifting correctly but it was intermittent. At about 26000 miles, it started to not shift into overdrive until about 10-15 minutes of operation. This problem become constant and the dealer agreed there was a problem but could not find it. I left it there and finally they got a code after a week of driving it and they rebuilt the transmission (found broken parts inside). I drove it for a day and then a clicking in first gear started. They rebuilt the tranny a second time (more broken parts inside). I drove it for a week and there seemed to be a lag in shifting. I took it back and said it needed a new transmission. They agreed and replaced it and it works fine now. Other than being without my truck for a month altogether, I am satisfied with the outcome and I will continue to drive GM products. This process definitely cost GM a few dollars.

I also just bought (in June) a 03 Silverado and it's got a wicked clunk. The dealer said that it's a backlash in the drivetrain and there is nothing they can do about it. All they can do is record that I mention it everytime I bring in the vehicle. I suppose that's for when it actually breaks after the warrenty runs out so they'll fix it. I know I'll never buy the cheapy one again (cheapy one=$29,000)!

Cat

Hi guys,
I emailed the Chevrolet Customer Assistance center with a list of the issues and the details of how many times I have had it in for service on the clunk (4). They replied and asked that I call the call center 1-800-222-1020, which I did. After about 10 minutes of talking, the CSR put me on hold and called Young Chevrolet here in Omaha to get the scoop. When she came back on, she went through the usual talk of how the dealer has done everything that they can, and she also wanted to know if my concern was reliability. If you have been handed the bulletin at the dealer that says this "objectionable noise" is normal, you know what she was reading. I told her that was secondary, and that the NOISE is the primary concern. We talked another 10 minutes, as I did not want them to think that I was going to let this go by easily. She offered me a 6yr/75,000 mile extended warranty on the driveline for FREE. I did have to ask her to read what is covered. Their first offer did not include the front and rear differentials, or CV shafts, etc. I asked about those, and she added that in. Essentially, she said everything is covered except the engine. This includes the transmission, transfer case, u-joints, driveshafts, etc. I havent received the letter, yet. But, it's in the mail. When it comes, I will take it over to Young and have them review it to see if it will cover everything as an "extended warranty" or if there is a catch that I wasn't told. The CSR assured me there was no catch. I am a skeptic, for obvious reasons.
C

Also, on this same issue, I just heard a rumor last nite that GM is taking "bids" from outside engineers to solve this clunk issue. I have no details, but let's just say that my neighbor has a brother who is an engineer that is involved...I will share more when I get it. This is key, as I will not buy another GM 1/2 ton truck until the clunk issue is documented by GM as being resolved. I will buy a Dodge with the Hemi, before I will buy another GM 1500 truck.

Guys, I bought a new 2003 1500 silverado 4x4 ext cab in June of 2003. Had the "Clunk" from the beginning. Two dealers said it was "normal' according to GM specs. I fought with GM for 4 months to no avail. I filed a claim through their arbutrator the BBB. That was a Joke. I finally filed a Lemon Law claim through an attorney who specializes in Lemon Law claim and got a nice cash settlement form GM in about a month after getting the attorney. If anyone is interested you can email me and I'll be glad to share my experience and the name of the law firm. [email protected]

I did a bulletin search this morning and found a couple bulletins that MAY apply to the concern on your truck.
My recommendation is to take it back to the dealer and talk to the service manager and ask him to perform a bulletin search on your specific concern while you are standing there with him.
There are 2 bulletins for a 1-2 shudder on those trucks.
I had the 1-2 shudder on my 02 Sierra and I fixed it per the bulletin...Smooth as silk now
If you need more info feel free to PM me.

Gm Merlin I had a post that sounds ans you describe above, a shudder, or studder between 1st and second on my 2001 silverado, do you know the bulletin #

Man, I'm glad I came across this post! For months I have been bouncing between Dodge and Chev and finally settled on Chev. This info has once again put things up in the air.

Can anyone tell me of experiences with the 04'? I'm looking at the 2500 duramax, crew cab 4x4 automatic. Does this infamous clunk exist on this model?

dont know about that but my dad has a 03 2500HD crew with the 496. that thing is whisper quiet and i hear nothing in it. also drive the dodge. it sucks. the rear doors are almost half the size of the silverado. also my buddy i go to races with pulled a loaded 20 ft boxed in trailer and got 5-6 mpg on a 600 mile trip. the next time we took my dads 300 miles and averaged 12-13 with the same load. it pulled so good you can barely tell it is back there compared to the dodge. be sure to drive the dodge and know wht you are getting in to.

You'll only get the clunk with the 4L60E Transmssion. Just mainly annoying. It will short live vehicles that stop and go more. Like taxis and city cop cars. The allison trannys don't clunk. They just hang valves.

Stay cool

I am having a similar problem with my 03 silverado v6. When I let off of the gas and lightly reapply the gas, my tac will fluctuate wildy back and forth between 2,500 and 3,000, or at lower speeds, 1,000 and 1,500. A tach is not supposed to move up and down unless the truck's speed is fluctuating. I have constant speed, yet my tach is surging, along with my truck. I can feel this "misstep" that the motor, or transmission is taking. I have taken it to the dealer and they said something about a problem that GM released and they supposedly fixed it. I have taken it in 3 times and it is still doing the same thing. Do we have a crop of lemons here guys? I thought chevy was supposed to be the best truck on the market. I am seriously thinking of getting rid of mine. One more trip to the dealer, and if this time they cant fix it, I am getting rid of it. If anyone has had similar problems as mine please let me know.

Theres a bore in the valve body that wears out. G.M. has a campaign to "fix" them. From what the aftermarket people say. "It don't" We bore the valve body and install these TCC regulator valves made from special materials. From what I've seen, It takes a certain type of driving that prematurely wears out these bores. Some have 50,000 miles the next rig has 150,000 miles. 2001 the newest I've been through.

Hey, thanks for the reply. Do you know if your dad's got the allison or is it the 5 speed manual?

I've test driven the Dodge and can say this, you know it's a truck. With the weather the way it's been up here (Edmonton, Alberta Canada), the snow on the residential streets has melted then frozen over night for several days. You can just imagine the ruts and bumps. 60 kph down those streets and I was wishing for a kidney belt!

I too had the same problem. I had plans to buy a Superchips power programmer so I waited to see if that help. It really did, as soon as I reprogrammed the computer it shifted great.

costed about $300 for the prpgrammer but my truck is alot faster now :)

Thanks for your input - you described exactly what my truck (same yr/mod as yours) is doing. It is so loud sometimes that drivers next to me look over at my truck with a startled look on their faces! There's no way this kind of gear-slamming can be "normal". I've brought it to my dealers attention two times, both times they say its not a problem. The first time they upgraded the TCM software, the seceond time they just gave it back to me and said it was OK.

I am going to go back a third time and let them know it's not OK, and that I will be pursuing it upstream until it's fixed. This truck had a $38,000+ sticker on it, and is a fantastic vehicle in every way except the clunking drivetrain. I bought this unit to tow a travel trailer and am very concerned that towing might make it worse. No way am I going to let up on this though... it's clearly their problem to fix.




The bulletin reads:

During a 2-3 upshift, the 2-4 band is released and the 3-4 clutch is applied. The timing of this shift can cause a momentary torque reversal of the output shaft that results in a clunk noise. This same torque reversal can also occur on the 3-2 downshift when the 3-4 clutch is released and the 2-4 band applied. This condition may be worse on 4-wheel drive vehicle due to the additionmal tolerances in the transfer case.

This is a normal condition. No repairs should be attempted.

This applies to all light duty trucks 2003 and older.

You have to step up the HD truck to avoid this problem. You would think that they would fix the problem after all of these years, but as long as they are selling them there will be no fix. Chevy refuses to due anything about this problem.[/QUOTE]

There are LEGAL remedies to this problem and it's the ONLY remedy that GM will listen too, if enough people will do it. I gave some detail in a few post back. I was successful and driving a new 2004, 2500HD with no clunking problem and GM paid for most of it. Only the consumer can stop this kind of manufacturing.

Hi guys,
My 2001 Z71 (26000 miles) has clunks in the driveline as well. Park to reverse, 1-2,2-3,2-1. The most annoying clunk I hate is the one when you go around a corner slow and then ease into the gas again. CLUNK!


Wow, this exactly describes the noise I have had on my 2001 Silverado since I bought it. It is just the 2wd extended cab LS with the 4.8L w/ 44,000 miles. Truck never seemed to have a problem and ran fine, so I ignored it. I have a superchip on order (should arrive today WOOHOOO!!) and will see if that makes a difference.

On a side note, I did have to rebuild the transmission recently because 3rd gear was burned and the torque converter was slipping :mad:

i think some of you might find this interesting, i got it from another forum......

Here is the text from the TSB for the 'clunk':

Drive Axles, Rear - Clunk, Bump, or Squawk Noise

File In Section: 04 - Driveline Axle

Bulletin No.: 01-04-17-004

Date: October, 2001

TECHNICAL

Subject:
Clunk, Bump or Squawk when Vehicle Comes to Complete Stop or Accelerating from Complete Stop (Replace Rear Drive Shaft Nickel-Plated Slip Yoke)


Models:
1999-2002 Chevrolet and GMC Extended Cab Short Box Pickup Models (Silverado and Sierra)
with 4L60-E (RPO M30) or 4L80-E (RPO MT1) Automatic Transmission and Automatic 4WD (RPO NP8)


Condition

Some customers may comment on a clunk, bump or squawk noise when the vehicle comes to a stop or when accelerating from a complete stop.

Cause

A slip/stick condition between the transfer case output shaft and the drive shaft slip yoke may cause this condition.



"IM A CHEVY TRANS TECH AND I PAY MY MORTGAGE OFF OF THE DRIVELINE CLUNK.GM SHOULD MAKE A RECALL BUT THEY WON'T.UNDER WARRANTY I REPLACE THE YOLK FOR 4WD'S WITH A NICKEL PLATED YOLK.BUT OUT OF WARRANTY-I REMOVE AND LUBE D/SHAFT AT TRANS WITH GM "SPECIAL LUBE"-GM PART#12345879 DON'T USE YOUR HANDS USE A FLAT TIP SCREWDRIVER AND PUT SOME IN D/SHAFT YOLK AND TRANSFER CASE HOUSING-SHOULD TAKE 10 MINS TO DO AND LAST UP TO 30K MILES-OR BRING TO ME AND I'LL DO IT FOR ABOUT 75.00"

i think its about time chevrolet does a recall....i cant afford 600 bucks for a new "nickel plated yolk"

I'm new to this forum, so thanks in advance for any help.

I have a 2003 Z71. It now has about 12000 miles on it. The clunking problem started at about 3000 miles and was limited to shifts between 1st and 2nd gear. It has been back to the dealer 7 times for this problem.

The tranny was reporgrammed, a nickle plated slip yoke was installed, controls on the 4x4 were replaced, a jumper wire was added to the alternator to reduce electronic noise and now I have a more pronounced clunk between 1 and 2, and it's starting to clunk between all gears.

I've tried to sell the truck, but to two guys that test drove it both said is sounds like it have a U-joint out and was abused! (It's never been off the road.) It has now gotten to the point where I drive my '95 Buick instead of my new truck. It's driving me nuts.

Short of hiring a lawer, is there any way of actully fixing this problem?

Jim

Junk,2003 Silvarado lt 4x4, x-cab loaded top of the line Junk.I have allways been a ford man,I bought this Junk In new In 2003. It still looks like new, the cost list $39,000 I take pride In everything I own, even this Junk.You see I not only have the Famous G M.Clunk,But I aslo have the Famous Piston Slap boy Is this a treat to drive.People make fun of my truck,they stair at me.It gets so loud you can hear It down the block,even my kids make fun of my truck,The file on this truck Is so thick.I,v been at the dealer least 15 times,bad windows,bad trim,bad computers,bad seats,bad egnestion,bad drivers seat that rocks when start and stop at take offs, they tell me this Is Normal,as with the Clunk,as with the Piston slap.as with everything else.I,v been gone to the service manager,sales manager.the owner of the company,the attorney genreals office, the bbb,many,many many calls to customer service,nothing done yet.customer service Is down right Nasty,and Rude.they have even Yelled at me,called me a Lier,and said you own It, Its Normal they Suck,big time. The bank won,t help and they own the truck.G.M knows knows how to fix this problem and It will cost them in the billons to do so.They would rather dump there junk on us.I will never buy a G M car or truck again.I will also be going to the Portland,Oregonian to tell them my story and anybody else that will listen.I will make this my Mission.I,m not going to eat this.I would love everybody out that that has one of these Junks in there drive way to, email me at [email protected] Lets get together and stop Big businness like G.M.from f -us over they need to be stopped.Maybe we should all have a Big Bon fire in front of the dealers stores that sell this garbage,let me know.And yes I,m sorry but I,m sick of being sick of this lemon,lemon,lemon,pison slap,clunk,clunk, junk, junk,Steve.O. Also go check out www.piston slap.com Built like junk

dgamage: I tried to send you an email to obtain the information you are offer, but the message bounced. Can you provide an updated email or post the name of the law firm? There is a growing number of folks here in the NW that want to pursue this issue in a class action format. Thanks!


Guys, I bought a new 2003 1500 silverado 4x4 ext cab in June of 2003. Had the "Clunk" from the beginning. Two dealers said it was "normal' according to GM specs. I fought with GM for 4 months to no avail. I filed a claim through their arbutrator the BBB. That was a Joke. I finally filed a Lemon Law claim through an attorney who specializes in Lemon Law claim and got a nice cash settlement form GM in about a month after getting the attorney. If anyone is interested you can email me and I'll be glad to share my experience and the name of the law firm. [email protected]

dgamage: I tried to send you an email to obtain the information you are offer, but the message bounced. Can you provide an updated email or post the name of the law firm? There is a growing number of folks here in the NW that want to pursue this issue in a class action format. Thanks!
Hello I,m not sure how this all works so let me know If this Is working my email address Is [email protected] or [email protected] would loke to get in on a class action suit,can you help Steven

I,m going to our local Portland Orgegonian this Whensday the 19th and try to get them to due a story on this issue.I,m, sure they will as they have in the past.anyone that would like to hook up and tell me there story pleas do at [email protected] or [email protected] thanks.PS dont, buy gas on the 19th of may,these gas prices are killing all of us,Its like getting away with murder

Hi guys,
My 2001 Z71 (26000 miles) has clunks in the driveline as well. Park to reverse, 1-2,2-3,2-1. The most annoying clunk I hate is the one when you go around a corner slow and then ease into the gas again. CLUNK!
I am told it is because of the auto-trac system.
I can believe that. I also believe there to be some engineering defect.
If you change your own oil, next time you are under your truck, grab the "small" driveshaft that comes out of the transfer case and turn it. You will hear the noise in the transfer case. GEEZ. I cannot believe the noise that mine is making is not causing damage.
I have taken it in 3 times. The service writer is a good friend of mine. I have a good friend that is an area GM rep for GMSPO. I have seen the bulletins and, apparently, there is nothing that can be done under the existing policies that GM.
Keep calling and writing GM, as the dealer apparently doesnt want anyone to buy another 1500 4x4. The service mgr wouldnt even take the time to talk with me at Young Chevrolet when I called. I even have a friend, who's wedding I was in, that is asst parts mgr there.
PS: They replaced the "yoke" already right after I bought it with 17k, and another dealer (where I used to work) replaced the rear diff later after my 2nd trip to a dealer. The rear diff replacement cleared up the park to drive clunk I had.

Let me know know if anyone hears anything good from GM.
hello have you gotten the trans problem fixed yet?Do you have the piston slap? cold or hot starts?Do you have any ideas to help?

[QUOTE=dgamage]Guys, I bought a new 2003 1500 silverado 4x4 ext cab in June of 2003. Had the "Clunk" from the beginning. Two dealers said it was "normal' according to GM specs. I fought with GM for 4 months to no avail. I filed a claim through their arbutrator the BBB. That was a Joke. I finally filed a Lemon Law claim through an attorney who specializes in Lemon Law claim and got a nice cash settlement form GM in about a month after getting the attorney. If anyone is interested you can email me and I'll be glad to share my experience and the name of the law firm. [email protected][/QUOTE HELLO i TRIED TO EMAIL YOU AND iT BOUNCED BACK,iD LIKE MORE IMFORMATION ON THE LAW FRIM YOUR YOU USED THANKS STEVEN [email protected]

Do the drive shafts still have the carbonfibre sleeve. The older Chevs did my 98 shop truck had the sleeve until it cracked and wrapped up in pieces. We cut it off, since then the drive shaft clunks. this was used as a vibration damper/ silencer. Maybe the newer style truck no longer has this?

The new 2500 do have the same problems. both the stuttering in cruise control going down hills and the noise between 1st and 2nd gears. The 1st dealership showed me a piece of paperwork that states that the noise should be considered as normal but to try these steps to see if it helps the problem. But the paper doesn't show the steps and he didn't know what they were. My truck has 1700 miles on it. I wish I had known of this before i bought it. Now what? Well off to another dealership to see what they say.

had same problem on 2000 k1500, dealer did grease, yoke, did not fix

decided to try myself and noticed a lot of rear spring wrap and the driveshaft snaping up and down as axle hosing twisted so i installed some torsion springs i got from jcwhitney to the front of the rear springs and i havent heard that dam clunk since, have since put on a supercharger ,lift and 35's and replaced springs with a nice set of stainless torsion bars from rcd and there is no clunk and the rear end hook up awsum, no clunk no shudder no wheeel hope, just squits and goes,

I have a 99' z71 it cluncks when puttingit into gear and going into or out of reverse. The dealer says its normal ? I asked a machanic at work who has about 40 company vechicles 1500 and 2500 2wd he works on. He says "they all do that, drive it till it breaks". I hope that does not come to soon 56k seems to soon for a major repair. Does any one know will this harm the trucks drive train? Should I $hell out some cash now to avoid big buck?

sniff, sniff, i'm going to look at a ford to day!!!!!!!!!!!!!!!!!!

ok,, put some lader bars on the rear, Hmm why did'nt i think of that??
oh, lowering the line pressure , throught the computer ,will make it less pain full to put it in rev or drive .


Last winter it was snowing for about 3 months here in seattle ,and the wife drove it to work, I noticed as she was out in the street locking in the 4x4. I had her drive forward then stop and drive back, I noticed the left rear tire turned about 3/4 turn before it took up the lack in the rearend,Hmmm now what ,,,shim the spyder gears some more or what?

Does same problem exist with similarly equipped GMC Sierra, i.e. 2500HD with 6.0 Vortec and towing package?

Does same problem exist with similarly equipped GMC Sierra, i.e. 2500HD with 6.0 Vortec and towing package?

I have the 02, 2WD 2500HD with the tow pkg. and the two piece drive shaft. I never notice the slight clunk when towing my 6800 lb. travel trailer. But, I do have a slight clunk when coming off hwy run, stopping, then starting off again. Seems to only do it when hot. It is still under warranty, so may take it in and see what they say. Tech's on other groups say that grease will be temp. fix.

Thanks for reply, MCR10. I've seen lots of posts complaining about the "clunk". Oddly enough, I took it out today and no clunk whatsoever. Shifts smooth as silk. Dealer had told me the electronics sense driving habits and possible that my letting it sit for 2 weeks caused it to "reset" and in the process the clunking occurred. Sounds like a line to me, but it's O.K. now. Guess I'll wait and see if it recurs.

had same problem on 2000 k1500, dealer did grease, yoke, did not fix

decided to try myself and noticed a lot of rear spring wrap and the driveshaft snaping up and down as axle hosing twisted so i installed some torsion springs i got from jcwhitney to the front of the rear springs and i havent heard that dam clunk since, have since put on a supercharger ,lift and 35's and replaced springs with a nice set of stainless torsion bars from rcd and there is no clunk and the rear end hook up awsum, no clunk no shudder no wheeel hope, just squits and goes,

I have a 2000 K1500 that I bought with 36k miles on it and it didn't clunk. Now it has 41k on it and it clunks all of the time....but...when I pull a goose neck horse trailer or carry any load in the bed it doesn't clunk. In fact it drives and rides soooo much better with weight in the back. I have heard about the springs twisting and will look into that. Also, mjgjr72 what supercharger did you go with? I'm thnking about buying one but I need some advice please.
Sonny

I have a 2000 K1500 that I bought with 36k miles on it and it didn't clunk. Now it has 41k on it and it clunks all of the time....but...when I pull a goose neck horse trailer or carry any load in the bed it doesn't clunk. In fact it drives and rides soooo much better with weight in the back. I have heard about the springs twisting and will look into that. Also, mjgjr72 what supercharger did you go with? I'm thnking about buying one but I need some advice please.
Sonny

Same here with mine. Rides much better with weight in the back or pulling my trailer with approx. 1000 lb. tongue wt. No clunk or lag at all which indicates that it is not the trans. I have read on other groups that the HD's have a much stiffer suspension which, when unloaded in the rear, places the bed higher and the u-joints /drive shafts at a steeper angle which cause them to clunk somewhat. Unusual though, that mine only does it only after driving for sometime and everything is warm. Also, read a lot of info that greasing the spline is a temp fix. So, it sounds like it could be several things on diff. models causing the clunk. I am going to check under there for loose bolts or worn mounts and see if that could be causing some of it.
MR

Well I,m still here yes i still have this junk-clunk silvarado lt.I,ve gone to the knightridder news san franciso bay area, trying to get the freepress, to help,gone to the attorney generals office,gone to the portland oregon,spoke to a couple of attorneys her in portland,they say I have a case,I need others with the same problems to come forward.As a team we can kick there buts,One on one they win,what do you want to do let me Know thanks Steven owens email me at [email protected] or call 1-503-880-3069

Well I,m still here yes i still have this junk-clunk silvarado lt.I,ve gone to the knightridder news san franciso bay area, trying to get the freepress, to help,gone to the attorney generals office,gone to the portland oregon,spoke to a couple of attorneys her in portland,they say I have a case,I need others with the same problems to come forward.As a team we can kick there buts,One on one they win,what do you want to do let me Know thanks Steven owens email me at [email protected] or call 1-503-880-3069

I would guess your clunk is much worse than mine, hence I don't think I need to pursue legal action. That is not to say that mine will not get worse, but it did get better.......read on. I am looking at this problem from an engineering point of view; i.e. u-joint & cv-joint alignment/ misalignment, torque constraints etc. Below is a post I made the other day on alt.trucks.chevy. Check out the bolt tightening I did that relieved some of the clunk and see what you think about inserting some temp. spacers(wood or otherwise) in the space between the bottom springs and the next spring up. It is near impossible to put enough clamping force on the rear axle housing with the u-bolts to keep the axle and rear from rotating under certain acceleration conditions due to the bottom springs having a space between them and the upper springs. This is the only connection of axle housing to frame and why they left a space between the springs is a mystery to me; unless it was for a softer ride and still have the load capacity. It is not a sound design IMHO. If you take any of the steps below, be sure and let us know of your results and I will do the same.
TIA,
MR
--------------------------------------------------------------------
Post from alt.trucks.chevy
I happen to notice when I am towing my 30ft. RV, I don't have any
clunk at all in the rear end. I do have a little hesitation or
wrap-up and clunk or catch when not towing starting off from a stop.
My hitch weight is around 1k lbs. when towing and the truck is level
with the weight dist. hitch. So, I started looking at the spring and
axle configuration and saw that the bottom leaf at both ends only,
where the pads are, has about 1/2"- to 3/4" space between it and the
next leaf up when unloaded and not towing. When hitched up for towing
there is no space between the springs at all. I noticed that there is
no torque arms on the rear axle which mean that all the torque is
taken up in the springs at each end where they attach to the frame.
With the rear not loaded I put a wrench on the u-bolts that clamp the
springs to axle and was able to put approx. 3/4- to one turn on most
of the bolts. On a recent trip of 900 mile or so, I noticed that when
not towing most of the clunk/wrap-up is gone except when accelerating
rapidly. I plan to load the rear up with my trailer again and see if
I can take up on the bolts any more without over torquing them. I
would guess though, that it would be better to not have the space at
the ends of the bottom spring which would not rely on the u-bolts to
keep the axle housing from rotating. This I suspect is what lets the
u-joints get over misaligned so that they are out of spec on the max.
misalignment angles and causing a clunk or snap. I may cut some
blocks of wood to fill the spaces on the springs and see if that
completely eliminates the problem. I would like to hear if anyone
else has tried this.
TIA
MR

I have a 99' z71 it cluncks when puttingit into gear and going into or out of reverse. The dealer says its normal ? I asked a machanic at work who has about 40 company vechicles 1500 and 2500 2wd he works on. He says "they all do that, drive it till it breaks". I hope that does not come to soon 56k seems to soon for a major repair. Does any one know will this harm the trucks drive train? Should I $hell out some cash now to avoid big buck?

Darn. I should have read your post and that would have confirmed my thoughts about the rear end wrapping up and making the u-joints get over-axis and cause the clunking. The web site even has a diagram showing the results of wrap-up. Thanks a bunch. Looks like the RCD Trac-Link would be the answer without spending a bundle.
MR