We all know our TracRite limited slip differentials do not require friction modifier. Yet the vast majority of gear oils out there come premixed with the stuff. Maybe that's why there are so many complaints here about the slip not being limited enough, even with the emergency brake applied. I'm one of the complainers.

The only gear oil I've noticed so far that does not come premixed with friction modifier is this flavor of Redline. Maybe that's what I should use. Or will it cause things to chatter when making sharp turns? Any other brands out there without the stuff? Any other thoughts? Thanks, guys!

 

fredbert,

As you've probably read already, some are adding the friction modifier to stop chattering. I've had it too but it was as I started out from a stop with the front wheels turned, and just for the first few feet. Like when making a left in traffic. It started doing it after about 100,000 miles and while towing when it was warm.

I went to 75W140 Valvoline full synthetic and mine cleared up almost completely. More film strength at higher temps, I guess. It's an odd situation when we want the best lube possible, but better lube may mean worse performance.

I wish mine was more aggressive, but I can't say it changed with the oil change. Bigger tires make it seem less aggressive too.

I'd like to hear how the Redline works.


John

 

I asked Redline the same question (just ordered oil). The guy there suggested to use the regular stuff, as opposed to the NS, because the additive in the regular stuff is apparently helpful to the ring and pinion anyway and won't hurt anything.

I ran the regular 75-w140 in my last truck (03) with good results, but this one has the limited slip. I'll be putting regular 75-140 in this one as well (75-90 in the front).

 

The additive is a friction modifier, but contrary to popular belief, it actually makes things slipperier ( is that a word? ), not stickier !? It should not affect anything, and I HAVE heard some people say it took care of their chatering and such in the AAM axles. I don't understand because theoretically, there aren't any clutches to chatter in the AAM, but if it helped , it helped!

 

Yeah, I remember a thread about someone using gear oil with no additive in the AAM reporting that it chattered until he put in additive, even though it isn't supposed to need additive...

That's why I asked the guy at Redline if I should be ordering 75-140 or the 75-140NS (no limited slip additive). He said basically that the AAM limited slip system shouldn't chatter using oil without the additive (NS), but that using the regular oil that has the additive would be beneficial anyway, because it reduces both friction and temp of the oil on the gearface.

 

There may not be clutches but there composite brake shoes that act like clutches to activate the TQ bias.

Some oils will chatter some won't. It has to do with film strength, temp, and formulation which varies widely between lubes.

It doesn't seem to matter what size tires, what oil, etc. If you have one that works it works in all conditions. If not, anything temds to interfere with it working.

 

Ahhh....I wondered what those shoes were made of! They talk about them in the class I went to, but nothing in any great detail! That makes tons more sense now, as to why it cures some issues! That, and the class I went to was about 5 years ago!