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2002 Bravada Front Diff Case Busted.


skdpsmith
01-10-2008, 03:36 PM
Hello,

2002 Bravada started having the binding turn problem about 9 months ago. We had the transfer case fluid replaced and problem got slightly better but never went away. About month ago I noticed what I thought was a small oil leak. Well the other day I go in the garage and a see oil all over the place where the wife had parked the night before. I found 3 or 4 pieces of broken diff case when I removed the plastic skid plate. I think it is busted on top somewhere and I think the gears are okay.

Anyone ran into this before?

I friend of mine that used to work at the GM dealership here said that there was a recall on the case where they were to install a washer on the rear most bolt to help with alignment and one of the problems was that it could cause the case to crack. I cannot find any info about it on the web though.

Any info would be greatly appreciated.

Thanks,
Scott

Chris Stewart
01-10-2008, 05:19 PM
Sorry about the busted case, I don't know anything about it. Maybe someone who does know will post.

wardak33
01-12-2008, 02:46 PM
I had the same problem too. but mine didn't get to the point where it cracked. As soon as i saw the oil leaking, i took it to someone to see what the problem was. It was a broken seal. Parts=$40, labor cost over $1000. had to drop the whole tranny. i don't know what could've caused yours to crack, but always make sure you have enough oil. I believe there was a recall on it, but to make sure that your car is covered, call any GM dealer, and ask them to look up all recalls for your car. They'll ask you for the last 8 digits of your VIN number. That way they can look up and perform any recalls that were called for your specific car. Hope this helps!!!

old_master
01-12-2008, 04:05 PM
Did the differential case crack or the transfer case? Differential is what the axles go into. Transfer case bolts to the rear of the transmission.

skdpsmith
01-14-2008, 11:24 AM
Front diff case. Got it all apart - shew! Had to take the oil pan off to get it out. Ring Gear bolt broke and went through the case. Gears look fine. Ordered case from GM today - $673 with new seals, ring gear bolts and fluid.

skdpsmith
01-14-2008, 01:43 PM
Question about the hard turning.
How the heck can the transfer case have anything to do with it?

All the transfer case does is engage 4WD right? If its stuck in 4WD it should still turn easy - shouldn't it?

I would think that the problem would be that either the front wheels or back wheels are locked together like the clutches in the carrier were messed up or something. My mustang race car is hard to turn because it has a spool in the rear end and thats what it feels like in the bravada.

Any insight?

Thanks

Chris Stewart
01-14-2008, 07:19 PM
Yup, same thing with the locked up transfer case only the gear train isn't as tough as your spool & axles. The '98 & newer lock up solid when engaged. Changing the transfer case fluid to the blue AutotracII, running it a coupla hundred miles then changing it out again reportedly unsticks the innards so it'll operate better.

The '91-'97 transfer case had dependable viscous clutch setup...which Olds should've kept, Borg-Warner was still making them but the techno-freak engineers at Olds wouldn't design them in and was part of the wrecking of the company...%*&(*)*!!!
Sorry gang...

skdpsmith
01-17-2008, 10:04 AM
So has anyone on here setup the front end on one of these?

What is the proper way to adjust the adjusters that hold the carrier?

Help - lol.

matt_o_70
01-29-2008, 12:22 AM
skdpsmith - I'd really like to hear from you after this is back together. Did the binding turning go away with the front end repair?

I am fairly new to a 2000, it binds when turning. it clicked before I changed the fliud. The Previous Owner had it looked at but was told that "they all do this" I am waiting to hear from someone who has ever fixed this condition..

since fluid change makes it better, I assume that there is a viscous clutch in this transferr case also, to make fluid changes mildly effective? since this is all wheel drive not 4WD - transfer case has to allow some slip.

Anyone on this board have a service manual that shows the drive train in detail?

Can one of you who have owned one long term comment on the binding/dragging? In a working Bravada do you feel the drag of the drive line when turning? It is very noticeable in mine?

old_master
01-29-2008, 06:57 AM
If front ride height is not within specs, the CV joints will bind when turning. Same principal as pinion angle; U joints and CV joints have a range that they are designed to operate in, if the angle is incorrect, they will bind. Mismatched tires and/or tire pressure can also cause it to bind.

skdpsmith
01-29-2008, 09:40 AM
I got it all back together and the front diff seems to be okay so far. No leaks anywhere - knock on wood. I followed the procedure I found here on the transfer case - change the fluid (blue autotrack II) drive it a few miles then change the fluid again. It is now probably the best it has been since I have owned as far as binding when turning. However it is still doing it very slightly and we have probably driven it a couple of hundred miles since the fluid change too.

I think read on here that the binding could be caused by the encoder motor on the transfer case or the computer? Anyone?

Is there a fuse I could remove to disable the AWD?

Thanks,
Scott

wardak33
01-29-2008, 11:54 AM
There is a fuse to disable it, but I don't know which one...I'll find out and post it by today. But your AWD shouldn't be on full time...only when you need it. It looks like there is something definetly wrong with your encoder motor. They are notorious for going bad many times. make sure you get that taken care of immediately, if not, then you're going to be looking for a new transfer case pretty soon.....(another $1300 to spend for you)... I'll make sure to find that fuse for you. all i remember is that it is under the hood on top of the driver side fenderwall, i'll post back to which specific fuse it is, it should say in the owners manual...

old_master
01-29-2008, 05:37 PM
The Bravada uses a NV 136 single speed automatic transfer case. Both front axle shafts are always engaged to the front differential. When the front and rear output shafts rotations are different, the shift control module commands the encoder motor to engage the transfer case into 4WD. Being that the axle shafts are always engaged to the differential, it can be difficult to determine what's causing the binding. If when you remove the front drive shaft, the vehicle still binds when turning, I would suspect CV joints, a difference in tire size left to right, or a wheel alignment problem. If the binding goes away, suspect the transfer case, or a difference in tire size front to rear.

Chris Stewart
01-30-2008, 10:32 AM
The fuse has been reported as the ATC fuse on other year models.

wardak33
02-12-2008, 01:34 PM
just wondering, but have you fixed your problem yet?

matt_o_70
02-14-2008, 03:01 PM
I have been experiencing similar situation (have only owned the bravada a few months) - did the fluid changes and drove but could still feel the added drag of the transfer case engaging the front driveline at all times.

I recently Pulled the "4WD" fuse on my 2000 and Instantly noticed that it drives 100% better exactly as I would expect for 2wd - I suggest you give it a try. It at least suggests that the transfer case motor is working (not stuck).

Now I need to find a service manual to better test the AWD system. I do not have any trouble lights on. So now the question is why is the transfer case being engaged. typically an AWD system is engaged when the sensors detect a difference in wheel speed or front/rear drive shaft speed.

I am hoping someone who has GM experience with these cars can chime in with some diagnostic insight.

be sure to check the basics first, tire pressure, and tire size/wear. a problem with one tire can cause a difference in front rear axle rotation due to the reduced rolling diameter of the tire with low pressure. Are all 4 of your tires the same condition?

SandyCamel
03-05-2008, 07:04 PM
:screwy: I have the 2003 Bravada AWD and I have been experiencing the same transfer gear case, differential, control motor, computer problem, or whatever the cause that creates the chatter, shaking, braking like symptoms whenever turning. The first incident the dealship said the transfer gear case oil needed changed. We did that. That eliminated the problem for a short while. I relocated to another area, and the problem started again. I took it to a different dealer, and they changed the oil. Yeah, it is a very special oil and they charge $175 for that service. Well, the symptoms started again. It just turned 40,000 miles-- and I have had it serviced by the book... I'll take it back to a dealership tomorrow to talk about permanent repair under warranty. I had bought an extended warranty. But, I suspect I'll encounter problems... like it is expired or the extended warranty does not cover this component. The point being, this site with everyone's comments, gives me some ammunition to take on a possible battle. I'll let you know the outcome.

skdpsmith
03-22-2008, 07:26 AM
Front Differential still okay - still no leaks BUT the binding is back. I changed the transfer case fluid twice just like the procedure said and it was okay for about a month but its back again.

Chris Stewart
03-23-2008, 10:19 PM
Are all 4 tires the same size and the front tires about 2psi more air than the rear?
Have you tried unplugging the ATC fuse just for a test?

skdpsmith
03-24-2008, 08:57 AM
All Four tires the same. Air pressure the same. I haven't tried the pulling the fuse yet.

DatsunRider510
08-19-2008, 09:51 AM
Guys...found this post...a bit old, but highly relevant to me. I have a 2002 olds Bravada (newest model, first ones off the assembly line). We were on vacation in SC (650 miles from home), and the front differential started making a horrible grinding noise. Gets especially bad when braking or slowing down. I've never seen a leak in the case, but is there a recall on anything in the front diff? Has anyone had this sort of issue? I suppose that it's possible there is a crack, and the leak has been really slow, leading to an empty case now. The car does spend a good deal of time away from the garage, and there is that big crossmember under it.

Also, as far as the transfer case issues, I switched to a race-grade Red Line auto tranmission fluid in the casing. I'll have to look at which fluid specifically, but I haven't had any binding or other issues with it in 50,000 miles. Screw that GM stuff.

reddog2110
09-19-2008, 11:36 AM
I have a 2000 bravada with the transfer case chatter. I just found out by taking my local GM service guy for a ride.

Symptoms: While moving forward and backwards at very low idle (parking) while turning, a vibration or shake in the drive train is present. Does not happen at regular/fast idle at all.

Unfortunately, he said my extended warranty probably will not cover whats wrong. He said the transfer case plug is probably corroded and needs to be cleaned and or replaced.

I'm going to unplug my ATC fuse for now and try and locate the plug he is talking about. Any feedback as to where this plug may be located specifcally would be helpful.

Thanks, Cliff

DAMNBRAVADAS
07-26-2012, 12:34 AM
Hello Everyone

My posted is mainly directed for old_master I have a 02 olds bravada.Back sometime last year in 2011 my service AWD light started coming on.Well needless to say I took it to my local dealer and was told my differentail was totally shot I paid nearly $2000 to have it repaired in June 2012:crying: and since then not only does the AWD light still go on and off but now the service ENGINE light is on as well:mad:. When I drive my car it feels like it's stalling or like it doesn't want to change gears or like it's skipping or jurking when changing gears:uhoh:. Do you know what might be causing these issues? You seem to have alot of knowledge on the BRAVADAS please help me if you can. Also are you any where near northren california?

Chris Stewart
07-26-2012, 06:40 PM
You can have the codes checked at most chain type auto parts stores free.
Post them for more clues to your problems.

ericn1300
07-31-2012, 12:31 AM
Welcome to Automotive Forums. This thread is 4 years old now and seemingly unrelated to your problems, you might get better results if you start a new thread with a better description of your problems in the title.

Protech Mobile
09-29-2012, 01:19 AM
Customer calls me up and says his bravada is stuck in the middle of the road out front of his house and wont move. Told him get a floor jack and move it back into the garage. Got out there and found both front axle boots clamps came apart and grease leaked out. So I started to remove the shafts to replace them. It was going well but the left side came out with a little resistance so it took a few more hits with the hammer. I hit the shaft and out popped the axle, so i crawled to that side of the vehicle and found the inside bearing was attached to the axle shaft and it had scored up the inside of the case pretty bad. Got out my flashlight and looked inside the axle shaft hole and it looked pretty dry and kind of rusty. Went around to the right side and i could see that grease had been lubricating that side but it wasnt runny like fluid should be. I put a drain pan under the front differential and removed the plug.....NO FLUID CAME OUT!! BONE DRY. LOOKED FURTHER INTO THE LEFT SIDE AXLE SHAFT HOUSING AND IT WAS ALL RUSTED ON THAT SIDE.
Anyone seen this yet? Customers says he has had the truck for a little over 4 years and never changed that fluid.
This doesnt look like a fun job to do on the ground. Is it true that the whole under cradle comes down and control arms too??
It appears the steering gear comes out but the nuts on the inside of the tunnel that the mounting bolts go through for the steering gear....all seized and a normal length socket wont fit over the long length of the bolt. This is one long bolt.
After the cradle is removed, should this be aligned also? I have not pulled one of these all wheel drive front diff. units off a vehicle yet since 2000.
My alldata doesnt say anything about alignment.

Chris Stewart
09-30-2012, 08:10 PM
Sorry, I'm not familiar and have no 2002 FSM.

Anyone else familiar?

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