Stoge

Are you sure about this? My car has grease zerks on the U-joints, and they have not been replaced since the car left St. Louis in 1979.

75 Hot One

My understanding is that all C3 U-joints have no grease fittings. I just checked the Volunteer catalogue and their 1968-82 listing confirms that, although they list U-joints with grease fittings as a service replacement. The Paragon catalogue lists both types of U-joints with no comment on which is OEM type. If you're saying yours were never changed, the later C3's must have changed to grease fittings.

75 Hot One

I just checked the Corvette Restoration Guide which has more detailed info for different year C3's. It definitely states that 1978-82 Corvettes have no grease fittings on the U-joints. If you got the car new and know the U-joints haven't been changed, it would be interesting to advise NCRS and see what they have to say.

Van Steel

Could be u-joints but it sounds like your clutch packs in the diff. Drain the diff and put new fluid and additive in. Put the additive in 1st. GM sells it so go to your local dealer and pick up 2 bottles of fluid and 1 bottle of additive. The sound may not go away right away so go do some figure 8's in a parking lot to mix everything up.

Van Steel

Well I could offer 5% or 10% off and bump shipping charges up like other vendors do so you really don't get any kind of discount. Just some food for thought.

MEGALADON

LOL, so true. I never listen to the comments, as they only
want you check out their site so they can get more hits, on there site.
Lot of really nice cars there.

likindrivin

mine is an '81 and just had new ones installed which cost me $30 each :ack but the Napa Precision (?) were not holding up// On my half shafts, they stamped the Spicer no. to use: 429 (I think) and ditto on not using zerks.
I too am currently having problems with a new rotor but I believe it could be damage to the hub. the rivets were absolutely horrible to remove...the only way is by step-drilling up to a 3/8 " in the middle. but I hammered on them some before I resigned my self to drilling. Also, could be poor bearing installation, or improper 12 lb. torque and adjustment. Good luck. Jim

ACECO

Are you sure GM posi additive was added to the diff when it was rebuilt? W/o the posi additive, the diff/posi will pop, chatter, etc when turning. You should add 2 - 4 oz bottles of GM additive to the diff and then go do some tight figure 8's to work it into the posi clutches.

If this is the issue, the additive should resolve the noise.

Good Luck!

z3man987

i just dropped the car off at the place that redid my diff. he said they added the additive but said maybe it did need one more bottle. i guess only one bottle was put in so that advice on 2 bottles sounds good, thanks. ill get back with results.

z3man987

just got the vette back, turns out there was minor pinion seal leak and it did need another additive bottle. did some tight figures 8s and all is well now. thanks guys.