Differential Fluids

[MasterJake]

Is 75-90W Synthetic Gear Lube ok to use in an E99? Looking to do both front and rear difs this week. Would u guys reccomend a Friction Modifier?

 

[Arisley]

Should be fine and yes, use the friction modifier.

 

[Justin@DP-Tuner]

I believe the rear end calls for a 75w140 full synthetic, with friction modifier.

 

[bruce]

most synthetics don't need friction modifier. put the 75/140 in there and go make a tight turn, if the rear tires chirp then add a little at a time. I've never added friction modifier with the redline gear oil i use

 

[David N]

I've changed mine 3 times now and I've never used the friction modifier. Some oils come with it, and some don't. You just need to check the bottle.

My thought process was that I wanted to pull positive, so why add the modifier? Its never bothered me either.

 

[Montgomery P-Stroke]

Running the Mobil 75/140 LS in mine that already has the modifier in it. Seems to work the same as the factory fluid+modifier specs when it comes to pulling 2 tires.