D44 Trac-Lok limited slip - friction modifier? How to test?

mhead · Jan 16, 2006

About a year ago I rebuilt a D44 and swapped it into the back of my '92 XJ I6 Auto tranny. Works great!

At rebuilding I obtained a Trac-Lok which I think had recently been rebuilt with new clutches - but maybe I was misinformed. This I installed. I used Sta-Lube SAE 75W90 GL-5 Plus gear oil that says it is for limited slip differentials. I don't remember if I added extra additive.

At the time things seemed fine. Today however if I put the tranny in N and jack one wheel off the ground I can turn this wheel by hand with relative ease. My memory of the Trac-Lok is that I should encounter a great deal of resistance when turning one wheel and having the other one fixed.

I attempted the 'wheel on pavement other wheel on grass' test several times with the wheel on grass spinning sometimes and sometimes not. Inconclusive...

So, first question is how do I test the Trac-Lok to see if it works or not?

Next question, Is it possible that if I add friction modifier my Trac-Lok will start working?

And last, any recommendations for friction modifier to use?

Thanks!

MJR · Jan 16, 2006

You need about 8oz (one bottle) of modifier. I don't know of any oil that comes with it already (may be). Trac-locks are real limited and wear quickly (about 16K mi) but sometimes can be made to work using a little e-brake application.

Mike R

Tim_MN · Jan 16, 2006

I have trac loc in my XJ and it still works well at 65,000 miles. The diff fluid (synthetic) and friction additive have been changed regularly. The trac loc in my CJ-7 works when it feels like it, sometimes from one minute to the next. At 130,000 miles I would expect that. I did get better results in the CJ after I changed the nasty old fluid and added fresh friction modifier. Even if it says GL-5 I add some modifier, can't hurt anything. I got mine at NAPA.

mhead · Jan 17, 2006

Ok, I'll visit NAPA for some modifier. But after I toss it in, how will I test to see if it works or makes things better?

Thanks!

5-90 · Jan 17, 2006

Failing to use friction modifier with "clutch-type" traction devices will make the clutches chatter. No guarantees that you can recover the clutches when you start using the stuff again - you might need to pull the carrier and replace clutches.

You can, however, just mix FM with your stock of gear oil - since it only affects the clutches in LSDs, it can be used in nearly anything else without any ill effects. I've mixed FM with all my gear oil that I keep on the shelf (I've got a Track-Lock in my second 89, and I've got enough to keep straight...) and I'll use it in all of my axles (total: eight) and my Peugeot transmission - no trouble to report here. I've talked to some who use it as an additional "anti-wear" additive as a rule, and they've got no complaints either...

5-90

Digger87xj · Jan 17, 2006

mhead said:
About a year ago I rebuilt a D44 and swapped it into the back of my '92 XJ I6 Auto tranny. Works great!

At rebuilding I obtained a Trac-Lok which I think had recently been rebuilt with new clutches - but maybe I was misinformed. This I installed. I used Sta-Lube SAE 75W90 GL-5 Plus gear oil that says it is for limited slip differentials. I don't remember if I added extra additive. The Sta-lube is fine... all you should need.

At the time things seemed fine. Today however if I put the tranny in N and jack one wheel off the ground I can turn this wheel by hand with relative ease. My memory of the Trac-Lok is that I should encounter a great deal of resistance when turning one wheel and having the other one fixed. sounds like it's toast

I attempted the 'wheel on pavement other wheel on grass' test several times with the wheel on grass spinning sometimes and sometimes not. Inconclusive... toast again...

So, first question is how do I test the Trac-Lok to see if it works or not? you did. the 'factory' test is to raise one wheel up, trans in neutral and using a torque wrench on a lug, apply torque to the wheel...the trac-loc should start to give @ 100 ftlbs.

Next question, Is it possible that if I add friction modifier my Trac-Lok will start working?
nope
And last, any recommendations for friction modifier to use? the sta-lube is fine, or if you use plain 80-w90, buy the 4oz FM from mopar. one bottle does one diff.

Thanks!

D44 Trac-Lok limited slip - friction modifier? How to test?

mhead

NAXJA Forum User

MJR

NAXJA Forum User

Tim_MN

Freakish Hand Strength

mhead

NAXJA Forum User

5-90

NAXJA Forum User

Digger87xj

NAXJA Forum User

Similar threads