Rear End Fluid Choice....
Comments appreciated...
I spoke with my hardcore hot rod friend (Mustang in the 9's), and he said thinner might be better for greater fluid contact throughout the differential. In other words, the thinner stuff will find it's way into the tighter spaces where friction needs lube.
So, I'm still sitting on the fence with this one..
i don't see how the 85-140 can't get lube all the parts but i don't know? doesn't gm make 85-140 non synthetic?
Protection should not be an issue
We'll see at Bradenton this weekend with 20+ passes
Trending Topics
i used the heavier oil hoping it would ease my gear whine, but it diddnt
The Best V8 Stories One Small Block at Time
Thanks for the input folks, but I have talked to some gear specialists around town and although the manufacturer said to use 80W-90, no one thought it would be detrimental to go heavier. I might lose 1 HP or so, but I have had my share of rear end probs, and extra protection sounded good.
After my planned 20+ passes on Saturday, we'll see how it went.
I will have to monitor this
Yeah, I spoke to Joe yesterday at Strange to ask another question and decided to go over the fluid deal again. He told me to use 85-140 dino oil. He said the 85-140 protected against the shock caused by track use especially for manual cars or ones that use a manual trans brake better than the 80-90. He also told me that even if the car wasn't going to see much track time that he still recommend it for manual cars because that little bit of extra protection would go a long way for longer ring and pinion life. In fact ,he said Strange uses the 85-140 for the break-in period on all the 12-bolts. They use Valvoline brand, but said any major brand dino gear oil would work. He also directed me to use (1) 4oz. bottle of the GM additive EVEN IF the bottle of gear oil claims to already have it in the oil. So, there ya go....just a little more info for anyone who cares.
DO NOT USE WITH A CLUTCH TYPYE POSI , it will hate you , I know from experience.
No other gear oil carries the gl6 spec ,this is what the strange gear tech told me when
Iwas having issues with my rear.

Consensus is that there's not enough of it, so squeeze the extra 4 oz. in there.





