Friction Modifier, what is it....

I know I need it with my locker, but what is the stuff doing. I am working with a prototype part at work that gets compressed at 1300 lbs. It is such a tolerence that it will jam after 10 cycles with no lube. I used Lubriplate and achieved over 10,000 cycles without any problems, but I went out to the truck and got some NAPA dif fluid and the machine is running better then ever. I have some Redline in the Jeep and thaught about trying it, just to see if i can top the NAPA, but it says it contains Friction Modifiers allready. When this machine is compressed it will lock and hold hundreds of pounds, so friction is good. But locking up is bad......

Just trying to do some research, seemed like a great excuse to visit .

Gene MJ

You can see the "Serosphere" that i am workin on at www.ADandD.com who knows, you might find a use on your Jeep. We are getting ready to test one to 1 million cycles without being touched at double it max operating pressure. I need good lube.

If you have a "locker" you don't need friction modifier. Friction modifier is needed in clutch type limited slip differentials. Diff lube is extreme pressure lubricant (which is why it works well in the machine you mentioned). Howwver, it isn't formulated to allow clutch plates to slide, so friction modifier somehow alters the coefficient of friction to allow the clutches in a LSD to slip when they need to.

Thanks Eagle.

Got me back on track, I was under the impression i needed the modifier, Hopefully this post will helpt get just a few others back on track also, I have had a few say i needed it, maybe it wasn't here on .... but anyway, thanks,


Gene MJ

Re: Thanks Eagle.

Gene MJ said:

Got me back on track, I was under the impression i needed the modifier,

Click to expand...

What locker do you run? The factory Trac-Lok needs friction modifier, and the Auburn limited slip needs it. Those are the only two I can think of that fit any XJ axles that would need friction modifier. And neither is really a "locker."

Friction modifier is only needed on clutch type limited slips. Gear driven limited slips like a TrueTrac don't require it, nor do lockers which are all mechanical.

Your job sounds like fun....