GM 10 bolt clunky when warm

[Takid455]

After driving about 2hrs on the highway, I noticed the car would want to 'push' from a stop and make a 'clunking noise' reverse had the same issue. quite during straight curvy driving at high speeds.
Only noticed at low speeds.
seems like the posi is not slipping perhaps?



this morning after sitting overnight, all seemed fine.

I am assuming it has to do with the fluid getting warm. I use 85/ 90 wt w/ posi lube.

what is going on here?

[big gear head]

Did you use the GM oil additive or something else? If you didn't use the GM oil additive then that is most likely your problem. GM and Ford additive are all that I have found that actually work.

[Takid455]

I buy the oil w/ lube in a big drum. it says it is compatible w/ GM posi lube. you never know. I suppose draining the rear and refilling it w/ GM stuff would be worth a try.

[BonzoHansen]

I don't think 'compatible with' is the same as 'contains'. Add the GM additive.

[qwik1320]

X2 on the GM additive

[big gear head]

Just put the GM additive in with the oil that is already in there. You might need to suck a little oil out to get the additive in there, but that's all you need to do. It will take a little while for the additive to work it's way into the places that it needs to go, so don't expect an instant fix.