Differential Fluid

[GrndNatnl]

About to squirt in some new fluid. What would some of you recommend?..

• Regular hypoid gear oil, and add a 4oz bottle of GM limited slip addative?
  
  -or-
  
• Full synthetic gear oil? (ie: Mobil 1 stuff)

80w-90 correct weight?

Mine used to chatter like a sonofa a while ago. So I added a bottle of GM posi juice and it cured right up. I just want to put some new oil in there for peace of mind. Plus hot weather is on the way and I like fresh fluids in the car.

Has anyone had chatter w/ full syn gear lube and had to add the posi-addative anyway?

 

[bandwidthpolice]

I used synthetic and it showed me a bunch of leaks. I had to JB Weld the dimples where the axle tubes are crimped to stop the leak. Why they became porous I have no idea. I suggest regular 75W-90 + posi lube. I used Coastal brand fluid from Autozone (2 quarts, maybe 2.25) and one 8 oz? GM posi lube the second time with no ill effects. Cheaper too.

 

[EFFNQWKWE4]

I just did mine about a month ago when I replaced my cover with one that has a drain plug. I used Mobil 1 full syn. gear oil, AND added a tube of generic posi lube. No probs here. I always lean towards the Mobil 1 stuff, you get what you pay for! I talked with the guy that sold me the cover, and if you're going to replace yours with a new one with a drain-- be sure to get an extra quart of fluid and an extra bottle of the GM posi lube. He filled his with the extra fluid, but didn't use extra lube and got chatter. HTH


P.S.--
Wear gloves and don't get any of the gear oil on you.....smells like dog poop and hot garbage!