Trac-Lok Anti-Spin Rear Differential

[Jt-wrx]

levels as i've come to understand

1. Open Diff with bld system factory (pretty dang good, extra for snow/mud, will still go in the rocks but with drama...you need spin to engage)
2. LSD, trac-loc type - clutch pack based (mine lasted maybe 60,000 kms in ram 1500...hate this option, why bother?)
3. LSD, true-trac - torsion style - gear style, no clutch packs to wear our or special oils required (the ultimate LSD's, love this option, less drama than bld offroad, better than all other options on road)
4. Lockers, be it lunch box, e-lockers, air lockers, spools...not really the best street options but remove most of the drama offroad, excel in rocks.

Doesn't team currie run a selectable locker rear with a true-trac lsd front for crawling competition? I believe they won like that. The advantage of the true-trac up front was steering tightness and ease was maintained and even more so with the rear left open, they only locked the rear when absolutely necessary.

For the street and the dreaded one wheel spin in 2wd trying to come around a corner into traffic i'd want the true-trac in the rear also...but if straight up winning competition rig runs a true-trac up front and rarely needs to lock the rear...hmmm

I've done surprisingly well in deep crusted snow with sport s and open diffs with bld. Having had a trac-loc clutch pack style before i'd rather not have one again and step up the torsion gear style lsd and know it's always going to work not wonder when it will need to be 're-done'. Option #2. is the worst option imo.

Now if Jeep would allow factory order of gear sets and eaton available locker options life would really be good. Mine would have come with 4.88's and true-trac's lol.

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[ratherbskiing]

Last week, I had my rear diff fluid changed by Jeep dealer in my 09JKU with the factory LSD. I have the lifetime powertrain warranty so I specifically asked them to inspect for LSD wear and replace if necessary. They found no need to service or replace the LSD. 110,000 miles, wheeled regularly and extremely frequent use in snow. Maybe I just got lucky?

 

[Jt-wrx]

if they could use that bld system in 2wd for the rear to ensure fast safe merges into traffic making right turns onto streets i wouldn't need any of this stuff other than the bld that engages in 4wd...that's my single drivetrain pet peeve, trying to scoot into traffic and the inside goes spinning and hang me out to dry, not driving in 4wd all the time

yup you got lucky sir, and you looked after it cuz you got the warranty, well done, mine was spinnin like it wasn't there by 60,000 kms...like 40,000 miles

 

[1996XJ]

For everyone saying the Trac Lok will wear out every 30 or 80 thousand miles, Is this something that will happen even if the system is not in use like in a daily driving scenario? Or are we talking if you are off roading a lot and using the system?

 

[ShadowsPapa]

For everyone saying the Trac Lok will wear out every 30 or 80 thousand miles, Is this something that will happen even if the system is not in use like in a daily driving scenario? Or are we talking if you are off roading a lot and using the system?

I have no idea why they are saying that - I've had limited slip differentials in almost everything I've ever owned and NEVER had one give troubles or need service any more than a regular differential. They are used in racing and performance without issue. I've had them in cars and trucks, never an issue. I've rebuilt limited slip differentials over the years and never have run across any that gave out early unless ABUSED. I had one in my last Chevy and ordered this truck with the limited slip option and expect zero issues.
IMO - they only need service beyond normal differentials when abused. There will be the odd failures just like there are odd transmission failures and odd gear failures or anything else. But it's not a common thing.

 

[1996XJ]

Thanks i know you know what you are talking about. I think i am going to add the Trac Loc option to my Sport S build. So many people have different opinions on everything, like saying 32 inch tires caused them to need a regear on their JT yet the Willys trim comes with 32s and its the same 3.73 ratio as the other trims. I do plan on running 32s on the sport S but dont think ill be going max tow as i want the better MPG of the 3.73. And it will be a light duty truck just to carry basic tools and commuting nothing heavy duty or towing.

 

[redriderjf87]

If/when the stock lsd clutches wear out I'll definitely put in a true trac if they're out for the JT. Put one in my old 2wd B2300 danger ranger, worked pretty well even in that thing.

 

[legacy_etu]

I have no idea why they are saying that - I've had limited slip differentials in almost everything I've ever owned and NEVER had one give troubles or need service any more than a regular differential. They are used in racing and performance without issue. I've had them in cars and trucks, never an issue. I've rebuilt limited slip differentials over the years and never have run across any that gave out early unless ABUSED. I had one in my last Chevy and ordered this truck with the limited slip option and expect zero issues.
IMO - they only need service beyond normal differentials when abused. There will be the odd failures just like there are odd transmission failures and odd gear failures or anything else. But it's not a common thing.

Go read up on the JK forums. Jeep has been using these Trac Lok's for a long time and there's plenty of documented issues with these units. Mine failed and I don't abuse my Jeep and only go on the beach. Definitely not hard use. Mine failed right around 32K miles. By failed I mean all the spider gears had chips on them and this is the common failure mode of them, the spider gears chip leading to a loud clunk on takeoff. I've heard of some catastrophic failures if you ignore that clunk too long. There were large chips that drained out of my diff. when I checked it.

Replaced with Tru Trac and am so much happier with it.

 

[ShadowsPapa]

Go read up on the JK forums. Jeep has been using these Trac Lok's for a long time and there's plenty of documented issues with these units. Mine failed and I don't abuse my Jeep and only go on the beach. Definitely not hard use. Mine failed right around 32K miles. By failed I mean all the spider gears had chips on them and this is the common failure mode of them, the spider gears chip leading to a loud clunk on takeoff. I've heard of some catastrophic failures if you ignore that clunk too long. There were large chips that drained out of my diff. when I checked it.

Replaced with Tru Trac and am so much happier with it.

That's a different issue, though. They are having other issues - design issues, gear issues, whatever (maybe like the AXLE LEAK!)
Gears chipping is not because it's LSD, it's a flaw in their design.
I've had over 100,000 miles on LSD - I buy almost every new vehicle I can with LSD, AMX, Javelin, trucks, anything.
Forums are also not a good indication of how common problems are - it's where people gather like support groups. Visiting a forum to find how common something is, especially with vehicles like Jeeps for some of the other trucks - not any indicator.
Gear issues - and that's related to it being LSD?

 

[XJFanatic]

.A Torque Sensing LSD (TorSen), will do the same thing... lock when one wheel is slipping, but when you have one wheel in the air you can pump your hand brake and the diff will lock (TorSen diff is what a hummer has and pumping the handbrake is what they teach you in military or humvee driving school)

While I agree with you on the diff choice this made me laugh. HMMWV have pinion mounted brakes. What you stated makes sense for a normal corner mounted brake setup, it would do nothing on a HMMWV. Figures the military would teach it. (Going on the 14 year mark Active Army so these things they teach are funny to me).

Not meant as a jab at you.

 

[legacy_etu]

That's a different issue, though. They are having other issues - design issues, gear issues, whatever (maybe like the AXLE LEAK!)
Gears chipping is not because it's LSD, it's a flaw in their design.
I've had over 100,000 miles on LSD - I buy almost every new vehicle I can with LSD, AMX, Javelin, trucks, anything.
Forums are also not a good indication of how common problems are - it's where people gather like support groups. Visiting a forum to find how common something is, especially with vehicles like Jeeps for some of the other trucks - not any indicator.
Gear issues - and that's related to it being LSD?

whatever the cause is, is irrelevant. open diff JK s are NOT having spider gear failure, just the Trak Lok equipped units. Stating the failures are due to abuse is a guess on your part and I for one can refute and I did state my Jeep has had an easy life and it still failed. I do agree with you in terms of sampling failure rates from forums being tough/impossible but you can definitely see trends.

Im not saying LSD’s are inherently bad, just the Trac Lok.

I buy every vehicle as well with LSD units….not sure what your point is here. Familiarity?. I know how they work and this is the only one I’ve ever had issue with.

Interesting thing to note was the shop that swapped my True Trac in stated that the bearing cap was installed backwards. have no idea if that could have lead to this failure. I’ve owned the Jeep since new so it was a factory mistake it would appear.

 

[mtudb24]

Have had many trac-loks in either Jeeps or Ram trucks and haven't had any problems (maybe I'm in the lucky bucket). Actually the only "clutch pack" diff I have ever had an issue with (and it was with 3 of them) was the Famous (or Infamous depending on how you look at it) GM G80 RPO code called the Gov-lok. Blew one out in a square body blazer, 1 in a fullsize Tahoe, and 1 in a S10 ZR2. All GM 10 bolt rear axles.
Replaced them with Lock Rite locker (which was awesome back in the day) but they did chatter a bit when going around corners on the street.

If mine ever goes out in the JT (knock on wood it doesn't),, I'll be going with E-lockers or maybe ARB's.

 

[bd100]

I wore out a clutch unit on a Mustang, but they lasted the life of the vehicle for several Ford and Dodge trucks.

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