Got my 1998 Vette (29,000 miles) an oil change last Friday, and told them to make sure to check the diff fluid (first oil change since I got the car, didn't know when the fluid was last checked). The fluid level was fine, but there is a class 1 leak on the right side of the diff, where the side plate goes on. Just a seepage there, but definately a leak. The Service manager said he sees it a lot, even on new cars coming off the truck...anybody else have this problem, or know if it is a problem with the C5? If so...what is the "real" fix for the problem.

Thanks,
Kevin Paul

 

I had mine fixed twice, once for each side. Do a search and you will find alot of info on it.

 

I had a couple of drops a month hit the floor, not a big deal but I fixed it myself. The problem in my view is that the seal is very stiff and the car does not have a floating rear end. When your axles flex the cover has some flex and eventually the O ring seal allows some seapage. My o ring was soft and not distorted. The real fix would be use a sealant so if anything gets passed the o ring the glue is the last defense. The left side is weaker than the right side due to construction. Make sure they use a good sealant and all is well. I did the job in about 3 hrs. Not a bad job at all.

 

any pictures or instructions on pulling the side cover ?
Do you need to do an alignment after ?

 

From your description, it sound like the same problem I had - a bad seal where the half-shaft goes into the differential. Dealer replaced it and so far no more leaks.

 

I wouldn't mind having more details on your repair either. Did you take any photo's?

 

Your best bet is to consult the service manual as the instructions are simplified there. The main thing is to get the vehicle up high enough to work comfortably. You will have to loosen the Dr. side muffler assembly, so you need some height.You will not have to do an alignment. I do not have photos but the manual is very specific. If you have any specific questions don't hesitate to contact me. Unless you are out of warranty it might be best to go to the dealer.You must have a service manual for consultation.

 

I think C5-TECH has posted a few times about corrections to info in the service manual for the passenger side cover (which I believe is a little trickier than the driver side.) Worth a search.

 

Indeed, the passenger side is more involved. I did the O ring seal on the dr.side. The dr.side is most often the leaker. If it's the axle seal you will not have to remove the cover mostlikely. The seal is a very good one(design) and is quite beefy. My guess is that your leak relates to the cover o ring seal. Good luck.

 

Yes I had my differential leaking also. Talked to mechanic, he advised me to clean out my diff case vent valve. removed top cap off valve, sprayed carb cleaner into and around valve assmebly, best as I could, reinstalled valve cap. No leaks. Very tight quarters to work in, but it can be done with car on lift. Hope this helps :cheers:

 

Kurt :seeya

Nick

 

Gotta agree with Mike P. Check the vent valve first and clean it while you're there. My leak was fixed in stages until they got to the most expensive part. They replaced the o-ring which is a big culprit, the seal next, and then the cover itself (bad machining on the mating surface-known C5 problem). If you go that far, make sure you use a good anabolic sealant and do the bolts as well. :smash:

 

1. Raise and suitably support the vehicle.
2. Remove the LH rear tire and wheel assembly.
3. Remove the LH wheel drive shaft.
4. Remove the LH muffler assembly.
5. Drain the fluid from the differential.
6. Remove the damper/tuned absorber bolts.
7. Remove the damper/tuned absorber.
8. Loosen the nut retaining the transmission to the transmission LH mounting stud.
9. Install a second nut onto the stud.
10. Remove the stud from the differential cover (left).

12. Clean any dirt or debris from around the differential cover (left).
13. Remove the bolts (2) retaining the differential cover (left).
14. Remove the differential cover (left) from the differential.
15. Remove and discard the O-ring seal (4) from the differential side cover.
Installation Procedure

1. Clean the O-ring sealing surface on the differential cover (left) and the differential housing.
2. Install a new O-ring seal (4) to the differential cover (left).
3. Install the differential cover (left) to the differential.
Notice:
Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

4. Install the differential cover (left) retaining bolts. Tighten
Tighten the differential cover (left) bolts to 25 N·m (18 lb ft).
5. Using two nuts installed on the stud, install the transmission mounting stud to the differential cover (left). Tighten
Tighten the transmission mounting stud to 42 N·m (31 lb ft).
6. Remove the second nut from the transmission mounting stud.
7. Tighten the nut retaining the transmission to the transmission LH mounting stud. Tighten
Tighten the differential to transmission nut to 50 N·m (37 lb ft).

8. Install the damper/tuned absorber to the differential cover (left).
9. Install the bolts mounting the damper/tuned absorber to the differential cover (left). Tighten
Tighten the damper/tuned absorber mounting bolts to 25 N·m (18 lb ft).
10. Fill the differential with the proper fluids and to the proper level. Refer to Lubricant Change .
11. Install the LH muffler assembly. Refer to Muffler Replacement - Left in Engine Exhaust.
12. Install the LH wheel drive shaft. Refer to Wheel Drive Shaft Replacement in Wheel Drive Shafts.
13. Install the LH rear tire and wheel assembly. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
14. Lower the vehicle.

Right hand side similar to the left.




[Modified by Mike Mercury, 10:48 PM 11/13/2002]

 

Yup, had mine fixed by the dealer under warranty. Haven't checked again to see if it is still leaking. :cuss :cuss :cuss

This should have been a recall item IMO. :mad :mad

 

GM can't do a recall because they don't know how to fix it!! Well, I'm almost just kidding. They fixed my leak twice, and this time replaced the cover. :rolleyes:

 

Sorry to say KPP, you will need to repair this leak. I had the same leak. One morning I backed out my vette from the garage there stood a 2 inch puddle. At that time my car was under warranty and the dealer had my car for two days. Since then the differential has not leak. Keeping the fingers cross. :yesnod:

 

The vent is a long shot.A real long shot. Unless it is grossly overfilled I doubt this will be a possibility. The vent primarily stabilizes air expansion and keeps pressure from building. Not designed to leak!! Wipe the area down real good with brake cleaner/or degreaser and watch it over several days. The leak will show up at some point. Mostlikely its the O ring. Use sealer and reinstall or replace the o ring with sealer. The sealant is most important.

 

:flag

 

when I pull my plug it sunds like opening a can of cashews . Like it's got a vacumn instead of pressure ? :confused:

 

Thats your diff pressurizing because your diff vent valve is clogged and not allowing the build up preasure to vent. I had the same problem. Look through the replies for this problem under this persons request and you will see my fix. :cheers: