Rear Differential leaks

[pizzano]

I noticed today a drip which looks like it is coming from the drivers side of the differential, where the half shaft appears to be bolted up (circular plate with bolts), I would presume theres a gasket or some seal in there, does anyone have a rough idea what the Dealership will charge to reseal a differential, it appears to have been seeping for some time by the looks of the oily dirt around the casing and below it.

Any input would be appreciated, thnx

 

[pizzano]

Sounds like C4C5specialist to the rescue,lol, If a GM Tech replies to this, could you please tell me what all exactly entails this job(gaskets or seals that get replaced, so I know Im not getting hosed when they quote me for the job).

thnx in advance

 

[U.P. John]

I had mine in for some body shop service, and they noticed the differential leak(which was just starting to show itself). It seems there is a silent recall on this, but mine is an '04, and I don't know if that extends back to a '98, although it SHOULD!

 

[pizzano]

Is there a specific GM recall website to actually see what recalls were needed on specific year models,thnx

 

[c4c5specialist]

HI there,
There isnt a silent recall.
There have been a few technical service bulletins on this condition, with the final one being a revised service procedure.
This revised service procedure involves using an anerobic sealer with a revised oring and seal.
Then, running the vehicle for about an hour and rechecking the fluid level.
The differential must be HOT when you check the fluid, otherwise you could overfill it and then it will blow out the vent at the top left of the differential.
That service bulletin that I speak of is in the knowledgebase here on the website.
Allthebest, c4c5

 

[pizzano]

Was quoted $1400-1500 buks to reseal the differential, heck for $1000 buks I can get a new Diff with 3:42 gears in it, they said it might be a plugged vent on top, if this is the case I would think I would have fluid dripping down off of he top of the diff where the vent is, am I correct with this assumption.

And if it is the vent, is there a way to unplug it with it installed in the vehicle.

thnx

 

[1stiff84]

they said it might be a plugged vent on top, if this is the case I would think I would have fluid dripping down off of he top of the diff where the vent is, am I correct with this assumption.

No; with the vent plugged, no gas or liquid can escape from the top.

I had the same symptoms in our car. This is not uncommon to C5's.

 

[pizzano]

How is the vent unplugged then, is there a way to do it myself.

 

[Mike Mercury]

Was quoted $1400-1500 buks to reseal the differential,

that's crazy. You can buy the new style seal and anerobic sealer for under $35 and do it yourself.

FYI:

Carrier tranny center-shaft seal (A4): 24207010 $10.96

Seal Plate O-ring (A4): 12369456 List $10.75

aluminum 6" seal plate (A4): 12369457 List $51.00

The other seals are:

89047953 (new revision) side plate outer "O" ring seal (use with anerobic sealer) List $21.50

88996703 (new revision) output shaft(s) center seal List $18.01

89021677 - part number for the anerobic sealer Price ???

 

[pizzano]

Yes!, but the differential has to come out, all Labor costs I know,But Im not able to get the diff out myself (3 back surgerys allready)not able to do that much heavy duty work,especially on jackstands in my garage, Heck, bending over to do the plugs and wires caused me enough pain,lol

Im probably better off forking out 1000 buks for a New 3:42 rear axle and pay somone to put it in.

I really dont want to bring it to a dealer, Im sure the mechanics are well trained, but since when I had my 92 LPE in the dealership for a voltage problem some 2.5 years ago when I owned it,and they scratched the crap out of my front fender with a tool or something, and totally denied it , even though I had before and after pics of the vehicle, (just in case of something like that would happen),needless to say, It was a Pain in the arse dealing with there incompitence, thats why Dealerships kinda leave a sour taste in my mouth , if you will.

Thanx for the replies

 

[Vette1003]

I noticed today a drip which looks like it is coming from the drivers side of the differential, where the half shaft appears to be bolted up (circular plate with bolts), I would presume theres a gasket or some seal in there, does anyone have a rough idea what the Dealership will charge to reseal a differential, it appears to have been seeping for some time by the looks of the oily dirt around the casing and below it.

Any input would be appreciated, thnx

Drop me an e-mail. I will send you my write up with pictures and procedure. I took pictures and placed the article in a WORD document. Will be glad to share it with you. I had to replace my rear seal where the shaft goes into the rear end. That was the only part leaking on mne. You will need to inspect the larger plate o-ring seal to see if the leak is coming from there or the axle seal. Clean it up and run it for a hr. Then inspect ti closely.

I removed my seal from start to finish in 1 1/2 hrs. Cost me $13 for parts. Not hard to do unless you need an o-ring seal on the cover of the rear end. Still don't have to remove the rear end. There are several articles on this on the forums. I have heard that there are issues when replacing the o-ring.

I have posted my article on the forums. Let me know if I can help?

 

[c4c5specialist]

Hi there,
That pricing is plain and simple gouging.
Chilton book time to remove and replace the differential is 5.0 hours.
It takes 2.5 hours to reseal.
At our labor rate of $85 an hour, AT A DEALERSHIP, $637 plus parts.
Lets say they even included a 4 wheel alignment, which should be performed when the rear diff is removed, add $199.
So, even still, that is extreme price gouging.
Allthebest, c4c5

 

[Mike Mercury]

Yes!, but the differential has to come out,

...for side plate seals ???

who told you that ?

 

[pizzano]

Hi there,
That pricing is plain and simple gouging.
Chilton book time to remove and replace the differential is 5.0 hours.
It takes 2.5 hours to reseal.
At our labor rate of $85 an hour, AT A DEALERSHIP, $637 plus parts.
Lets say they even included a 4 wheel alignment, which should be performed when the rear diff is removed, add $199.
So, even still, that is extreme price gouging.
Allthebest, c4c5

That was a Chevy dealer who quoted me that also here in Vegas, I asked worst case scenario if the diff had to be removed, and that is what they told me.

c4c5specialist, is there a way to check if the vent is plugged,does it pop off or something to that nature. thnx

 

[c4c5specialist]

Hi there,
The vent is engineered to vent at 3 psi and allow vacuum when the differential is cooling. Vents clogging are very rare.
The first thing I would do is get the differential hot, and then see if any fluid comes out the fill plug.
That would be my first course of action.
Allthebest, c4c5

 

[pizzano]

Well , the fill plug is towards the back of the diff, the one with the tag on it correct, if so, it is bone dry around that area, all the staining is on the side and bottom under, that side, so Im suspecting the axle seals, I guess Ill have to resort to bring it to the dealership, thnx

 

[c4c5specialist]

Ok, but run it for about an hour, then remove the plug with a 10mm hex socket, and see if anything comes out.
If you have more than a drip, it was overfilled.
Allthebest, c4c5

 

[pizzano]

ok thnx,appreciate it, ill have to try that maybe this weekend,back to bad to crawl under right now, thnx again

 

[Dragon Daddy]

c4c5,

I have a '97 with 38K miles. The Diff fluid has never been changed. Is it about time?

Thanks.

 

[pizzano]

I finally took my 98 into a corvette shop,Here in Vegas, not a dealer, and my leak is coming from the side cover seal not the axle seal, so they are taking it out and resealing the whole thing, and also flushing the whole tranny and converter, all redline fluids being put back in with the proper friction additive, $1000 buks for everything, $800 buks cheapier then the dealership, I was told the tranny fluid and rear axle should at least be checked every 30k which I agree with in a performance vehicle.Damn! If i had 600 buks more I would just drop a new 3:42 in and pay them labor to install it, but the funds are limitied at this time and I just want the leaking to stop, and have a piece of mind that it will be done correctly, with no dealership hassles.

Thanx for all the replies and info, much appreciated