'00 Trans: 1-2 late, won't shift into R or 4

[DJSteve]

Short Version:
2000 Blazer 4x4, 4.3L V6, 4L60E trans, 118k
-High-revving between 1-2 shift (~3000 rpm / 20 mph)
-Will not engage reverse gear
-Will not shift into OD
-2-3 shift is fine
-No service engine soon light
-Stepping on brake and revving requires a firm foot on the brake to keep it from moving, indicating no major slippage. However, there is a change in sound at about 1500 rpm (where the 1-2 shift would normally occur) that sounds like it could be pump cavitation—sucking air.

Long version:
I bought a 2000 Blazer with 118k miles about a month and a half ago. The transmission fluid was slightly discolored, but did not smell burnt and everything shifted fine. I have since driven it about 1000 miles, ~300 of which was last weekend. After getting back from the trip I noticed it seemed like I had to give it quite a bit of gas to back up the driveway to my garage. Since I had about 500 lbs of DJ equipment in it and my driveway is fairly steep I didn’t think much of it.

I drove it on several short trips Sunday evening, Monday, and yesterday and everything was fine. This morning while driving to work I noticed it seemed to be revving a lot between the 1-2 shift. Once into 2nd everything was fine. A few hours later I went to leave for class, shifted into reverse, and had nothing. I stress—NOTHING. It does not make any sound (like the clunk you generally get when shifting an automatic into gear) and will rev just like it’s in neutral. I pulled the tranny dipstick and the level seemed to be ok, but I didn’t have anything to wipe it off with to check it exactly. The parking lot was damn near perfectly level, but fortunately there wasn’t a car parked opposite me… I was able to drive over the sidewalk/curb thing between the two rows of cars and was only a couple minutes late to class.

While driving to class, and from class home, I experienced the same high-revving 1-2 shift and lack of reverse. After doing some research online, I tried disconnecting the negative battery cable for a minute or so to reset the computer. No improvement. I drove around a little bit, found a level parking lot, and checked the fluid level. It was about in the middle of the operating range so I dumped in about a 1/2 quart of ATF. No change.

I needed to run back downtown because I forgot my PDA at work, so I stopped by O’Reilly’s and picked up a bottle of K&W Trans-X. This was recommended to me once by my family mechanic, and will generally improve any transmission problem resulting from slipping clutches/leaking seals. Decided to take it out on the highway to get things circulated, and discovered it also would not shift into 4th gear. Trans-X exhibited no change in the transmission’s operation.

In another parking lot I decided to do a ghetto load test—step on the brake and gas at the same time. I found I had to step on the brake pretty hard to keep it from moving, which leads me to believe the clutches are fine. However at about 1500 rpm the sound coming from the engine/transmission would change. Recalling THIS THREAD , I noted that it could be consistent with air being sucked into the trans’s hydraulic system.

To save you the trouble of reading that if you don’t want to, that owner had similar problems on an '01, and upon dropping the pan found that the transmission filter came out with it--and therefore had not been properly seated in the intake port.

I also understand 4L60E's have a fairly common issue with a pressure solenoid that can cause late 1-2 shifts... can this also affect 4th and R?

There are not any Autozones locally that I could go to to have codes checked, but as I mentioned in the short version the SES light has never come on (other than the normal pre-startup self test). I don't have anything too major going on this weekend, so I'm tempted to drop the pan and see what I find. Any thoughts?

[BlazerLT]

Instead of pulling the mechanic in a bottle routine, how about getting your transmission serviced with a new filter and new fluid and a complete flush.

Also, you do know you check the tranny fluid while the engine is running right?

[DJSteve]

Originally Posted by BlazerLT

Instead of pulling the mechanic in a bottle routine, how about getting your transmission serviced with a new filter and new fluid and a complete flush.

If I can find a reputable transmission shop I might... I don't know of one off-hand, though, and I'm somewhat leary of being sold a complete rebuild I don't need.

Originally Posted by BlazerLT

Also, you do know you check the tranny fluid while the engine is running right?

Yes. Contrary to popular belief, I am not a complete moron.

Back to the primary question I asked, what is the likelihood these symptoms might be related to a problem with the pressure solenoid or valvebody?

[goodtimepete]

A question on top of his question about tranny flushes....I had heard that sometimes a tranny flush can be worse for a car than it is worth...probably because the gomers doing it don't know what the H they are doing....what are your opinions...

[81montedriver]

go to AAMCO. They are the best trans people you can go to. Before they do any kind of work they do a transmission diagnostic test to find out the problem. Believe if or not, there are things that can be done to fix a trans without doing a rebuild. But most times it will need a rebuild. In your case it sounds like you may be low on trans fluid but it could very well be much more.

[BlazerLT]

Originally Posted by DJSteve

If I can find a reputable transmission shop I might... I don't know of one off-hand, though, and I'm somewhat leary of being sold a complete rebuild I don't need.



Yes. Contrary to popular belief, I am not a complete moron.

Back to the primary question I asked, what is the likelihood these symptoms might be related to a problem with the pressure solenoid or valvebody?

Problems could be caused by a lack of fluid maintanence and the filter could be clogged which will hinder the gear switch over.

Any shop will be able to install a new filter and flush the transmission, you don't need a tranny shop for that.

[DJSteve]

Originally Posted by BlazerLT

Problems could be caused by a lack of fluid maintanence and the filter could be clogged which will hinder the gear switch over.

Any shop will be able to install a new filter and flush the transmission, you don't need a tranny shop for that.

Since you seem to be dead set on a flush-n-fill, would you care to explain HOW this would cause two gears to stop engaging and one gear to not upshift correctly, overnight, while the other two gears still work perfectly?

Call me a skeptic if you want, but it sounds pretty far-fetched to me. If the filter was clogged wouldn't it affect all gears equally, or at least semi-equally?

[BlazerLT]

What do you have to lose?

100 flush and fill.

1500 tranny rebuild.

I have seen this because the filter is plugged and can't create proper pressure.

Also, if you want, reset the computer by pulling the negative battery cable and the two ECM fuses in the fuse panel to reset the computer.

The tranny is computer controlled so it could be logic lock in the computer and the reset might clear it.

[DJSteve]

Originally Posted by goodtimepete

A question on top of his question about tranny flushes....I had heard that sometimes a tranny flush can be worse for a car than it is worth...probably because the gomers doing it don't know what the H they are doing....what are your opinions...

I also have heard this, but extended to include not changing the fluid either. The reasoning I heard is that if a transmission has been neglected it's better to run it with the deposits stuck to the parts as long as you can, as opposed to putting in new ATF, or in the case of the flush, solvent, that will break the deposits loose and muck up the internals.

I would tend to buy into it, at least in some instances. I had an 84 chevy van (305/700R4) that the transmission fluid was pretty bad when I bought it. I drained it, replaced the filter and filled it back up with fresh fluid. About 150 miles later I didn't have 3rd gear anymore. I also had an '80 Cadillac (368/TH400) with absolutely THE SHITTIEST looking trans fluid I'd ever seen. I never changed it because I was scared to, and it never gave me a single problem.

[BlazerLT]

Originally Posted by DJSteve

I also have heard this, but extended to include not changing the fluid either. The reasoning I heard is that if a transmission has been neglected it's better to run it with the deposits stuck to the parts as long as you can, as opposed to putting in new ATF, or in the case of the flush, solvent, that will break the deposits loose and muck up the internals.

I would tend to buy into it, at least in some instances. I had an 84 chevy van (305/700R4) that the transmission fluid was pretty bad when I bought it. I drained it, replaced the filter and filled it back up with fresh fluid. About 150 miles later I didn't have 3rd gear anymore. I also had an '80 Cadillac (368/TH400) with absolutely THE SHITTIEST looking trans fluid I'd ever seen. I never changed it because I was scared to, and it never gave me a single problem.

This is an old wives tail.

[Turbocpe]

DJSteve, I know of a guy who worked for Ford as one of the lead persons in the engineering department for transmissions. He informed me of the same thing, if the transmission is neglected too long, it sometimes is best to leave it alone, unless you do a very, very, thorough job (perhaps like what BlazerLT suggests by doing a flush). Otherwise you risk disturbing any particles in the system.

[TonyMazz]

I'd drive by a dealer and ask a tranny guy if it's the Sun Reaction shell Gear housing ?
I had the same problem at 110,000 and it was metal fatique in the housing.....the OEM's just give way in 4L60E's...

When we backup our trucks then slip them into drive this puts strain on the shell housing....over time it just gives way...

A tranny guy ( with the right scan tool) can pull the codes from tranny...and tell you on the spot....Autozone can't..I have the same scanner they have and it only reads generic codes.....

Anyway...I don't think a flush-n-fill will do squat...you will get that if they have to replace this shell gear.

It cost me about $1200 complete, of course I put in a few new parts, but it's a 10.8 hour job......

Before I did anything, I'd have it scanned and they can tell you on the spot...wouldn't dink around with Spiffy lube and flush routine...

Just a thought....

[DJSteve]

Tony- I think you're (unfortunately) on the right track. Upon google searching based on the reverse issue I found a copy of the TSB GM released about the issue in November 99, several disgruntled 4L60E owners, and more than one reference to starting a class-action lawsuit.

Was the $1200 price tag at the dealer? Most of what I had seen posted was more in the $1500-2k range.

So I've owned the blazer a month and a half, driven it less than 1000 miles, and already (presumably) found two of the expensive weak spots--I replaced the fuel pump assembly last weekend. What should I anticipate failing next? The ball joints, fortunately, seem tight.

[TonyMazz]

Originally Posted by DJSteve

Tony- I think you're (unfortunately) on the right track. Upon google searching based on the reverse issue I found a copy of the TSB GM released about the issue in November 99, several disgruntled 4L60E owners, and more than one reference to starting a class-action lawsuit.

Was the $1200 price tag at the dealer? Most of what I had seen posted was more in the $1500-2k range.

So I've owned the blazer a month and a half, driven it less than 1000 miles, and already (presumably) found two of the expensive weak spots--I replaced the fuel pump assembly last weekend. What should I anticipate failing next? The ball joints, fortunately, seem tight.

This was at the dealer... where I was totally satisfied with their service.

Also alot of the problems with the 4L60E's are that they are related to folks towing and the OD going in and out and hammering the tranny to death. GM did not do a very good job with this whole deal as they were puting these trannies in (IMHO) too large a vehicle, i.e. tahoes, burbans and folks would tow and blow the tranny....

Anyway....again since you may need this work done, I'd have someone like a tranny specialist or GM tranny tech check it out first. I wouldn't flush-n-fill until you know...cause you could waste $100-$200 bucks on a flush-n-fill just to find you are flushed and f**ked...if you get what I mean....been there and done that....

Your next expense/efforts should be on diagnostics so you can do it right the first time.

[TonyMazz]

Originally Posted by Turbocpe

DJSteve, I know of a guy who worked for Ford as one of the lead persons in the engineering department for transmissions. He informed me of the same thing, if the transmission is neglected too long, it sometimes is best to leave it alone, unless you do a very, very, thorough job (perhaps like what BlazerLT suggests by doing a flush). Otherwise you risk disturbing any particles in the system.

yep and more specifically the particulates/clutch material gets into the valve body channels and mucks up the valve/shift valves.....
Hard to get out...Not a "Wives Tail" either.

Many people do the cheap flushes and it's best to do BOTh the flush AND filter change, drop the pan etc...they you get 90% of the crap out...