Well I just called Auburn today and asked them about running RP in the rearend and they told me that they do not recommend it. They said that it will lead to rearend chatter and slippage. I explained to them that I had the Auburn HP and was going to be pulling a 7500# trailer and wanted to run the RP for a cooler temp. They recommended useing ford synthetic said something about it being formulated to their spec. Does anybody out there have any experience with this. If I cant run the RP I thought about either a MAG-HYTEC or a TA Performance Diff. cover. any ideas on this.

 

I have a Mag-hytec and Royal Purple in it with no issues whatsoever.

 

Why not just run the Ford synthetic like they recommend? Synthetic is pretty much synthetic, RP won't run any cooler.

 

That was what I thought. But Auburn said that ford is a different formulation.
Ford must be semi synthetic??? I am also changing out my gears to motive 4.10's

 

What rearend are you running?? Auburn?

 

Ford 75W140 is full synthetic.