Looking for a good synthetic lube for the final drive, any ideas?

Don

 

I use Royal Purple w/ no probs, there's many out there. Make sure it has the slip juice in there, or buy a seperate bottle to add in so the clutches don't chatter.

Royal Purple can be had from Jegs.

 

I personally use valvoline 80w90 with the additive in my 9 bolt.

Miles
www.9bolt.com

 

Thanks, I read on the tech article here that if you use synthetic, the additive is not needed

Don

 

Can't hurt

 

there are no clutches in the 9bolt to chatter. I'm running pennzoil limited slip GL5 lube and it seems to be working OK. no extra additive.

 

You may find these interesting:

https://www.thirdgen.org/techbb2/sho...threadid=72062

this:

https://www.thirdgen.org/techbb2/sho...threadid=77011

and this:

https://www.thirdgen.org/techbb2/sho...light=additive

 

Wow, I didn't realize the can of worms about the slip additive. I guess it's an option between hard lockup and increased wear, or weak lock and extended life?

The tradeoff's to be made

 

Add the additive? YES ? NO? It's a heated debate... but here is my story...

Last week I tried a burnout in my car... 3.27 BW posi 9-bolt... I pulled a peg-leg....

I pulled the inspection cover and changed the rear fluid with some 75W90 Synthetic Gear Lube and added a bottle of GM Posi additive.... I will add here that the gear lube in my rear was seriously in need of a changing (although it was changed at some point because there was a silicone gasket) it was black and a little gritty.

All changed up I take my car out.... definitely feels like she is pulling better. Got to a stop sign yesterday, reved it up to 1000 rpm, let the brake go and jammed it.... two nice black stripes and a little sideways action..

Did the additive make a difference? Maybe, maybe not but I know my posi rear is working a whole lot better now!