Did Mobil 1 Rear End fluid change??

[Myty]

I put a Auburn chuck in about 9-10 years ago. I had used Mobil 1 fluid with no chatter or breakout ever! I put in the same 75-90 in a few weeks ago and it chatters Bad. Please give me your opinions. Thanks

 

[Slow91z]

No idea about Mobil but as for the car just add some posi additive...Shouldn't be a big deal.

 

[whitehot1]

Just add this to it and you should be good to go.

Trans-X® Posi-Trac® Limited Slip Gear Oil Additive by K & W Chemical - Part 402508 - Advance Auto Parts

 

[Myty]

Thanks!
I had thought I found the perfect fluid for the job and its synthetic. Additives in synthetic concerns me with Posi Break out on slicks.

 

[Dabigguy]

What is Posi Break out?

 

[GNeric]

My guess is terminology like "full race cam". :biggrin:

 

[1KWIKSIX]

Synthetic Oil in rear end

Thanks!
I had thought I found the perfect fluid for the job and its synthetic. Additives in synthetic concerns me with Posi Break out on slicks.

Had a new Auburn Pro Series Diff installed last year. In the installation instructions Auburn state "Do not use synthetic oil" in the rear end.

Guess it's too slipery. The Posi unit needs a certain amount of friction to function properly and synthetics will cause excess slippage.

Use a good dino oil and GM's rear end posi additive and you'll be fine.


dave

 

[Dabigguy]

My guess is terminology like "full race cam". :biggrin:

I could never afford a "full race" cam when I was younger. All I could afford was a "3/4" cam.

 

[GNeric]

HA!!! :biggrin:

 

[Myty]

Full Race. LOL!!

Break out = Posi to a one legger. When doing a line lock heat up.

One legger= One tire fire
Thanks