I have a strange 12 bolt and its time to change out the fluid. Strange told me to use non synthetic oil. Any reason for this? I would really like to run royal purple w/ gm additive.

 

Whats strange about the 12 bolt??? Nah jk. Anyway, I would use exactly what they say to use my man. Can't go wrong. Not to mention it'll be cheaper.

 

I think its just a little wigged out from all the 6k clutch drops

Just perfer royal purple everything, any extra 1-5 hp i can muster out of the car is good in my eyes.

 

I wouldnt use Royal Purple in anything. I switched to it from Mobil 1 syn. and had a lifter collapse. Since then Ive heard all kinds of stories, even cases of the oil dissapearing after a couple passes at the track.

 

I just got my 9" Moser and they also said not to use synthetic.

 

Moser says to use non synthedic due to the friction needed for the posi to work correctly

 

I am using a locker.

 

If it has a friction type posi, synth will be too slippery and the posi will not work properly.

Rich Krause

 

Well, i never even thought about the posi needing something less slick. Its the heavy duty Eaton unit, but i guess ill stick with standard. Thanks!

 

Absolutely! The Eaton is a clutch type posi and will not work as well with synth.

Rich Krause

 

You can add a bottle of GM friction moddifier.You can pick it up at the dealer.

Rob.

 

The best way to get "thee" answer is to go directly to the manufacturer of the product being discussed. Meaning, I have a Moser 12 Bolt in my 94Z M6 which includes an Eaton Posi. So, I went to the Eaton web site and printed out all the info I needed about my unit. I also called up Eaton and they advised me "NOT" to use synthetic gear oil as it might harm the clutches in my unit. Therefore, I only use "mineral based" gear oil.

Note: The seller of products is not always the expert. I actually called Moser about the gear oil and talked to several folks and received different answers. That is why it is always best to go to the manufacturer if possible. Better to make a decision on actual facts and not someone's opinion. An old saying applies here: "20 years of experience and 10 minures of knowledge." While a lot of folks have experience they do not really have the knowledge to make the most accurate decision.

A happy and safe holiday to all.