TruTrac Owners/Installers?

I'm looking at the newly available Tru-Trac for my 8.25. I talked to an installer that seemed to know what he's talking about and he said that the manual for the Tru-Trac says that if a wheel starts to spin you should STOP, apply brake pressure and then start again. Does it really say that? Is that really needed? He basically said he doesn't recommend them for Jeeps because he says something sounds really odd about that statement in the manual. I would just like to confirm that it really says this (or not).

Is there anything about the design that makes it weaker than other LSDs? I don't mean it's ability to prevent slippage, I just mean will the gears and the way it engages cause mechanical failure or breakage faster than a clutch type LSD? Does it engage with more of a "clunk" or suddeness than clutches?

Thanks.

I broke one while applying the brakes to get it to lock at about 3,000 RPM. That was an older unit, and about 6 years ago, and they have strengthened them since. Also, that was a Dana 30 unit, which has tiny internals compared to an 8.25.

They are fairly good at taking abuse, and you can get them to lock up pretty tight, so they have always been my favorite LSD.

CRASH

Sounds like your installer didn't understand what the manual is saying. I've had a TruTrac in my MJ for several years and I like it. It's street-friendly, yet more aggressive than the factory Trac-Lok LSDs.

The TruTrac requires some torque going to both wheels before it can lock up. In general (ice under one wheel perhaps being an exception), if you have both wheels on the ground you won't have to worry about it engaging. Off-road, if you get into a situation where one wheel is hanging in mid-air, then the unit may not engage, and that's when applying the brake can provide enough initial resistance to allow engagement. Of course, the situation Crash described is an extreme case. Imagine how much stress was suddenly put on the thing when it locked up at 3000 RPM.

I would recommend it very highly. Just remember, though ... it is a limited slip, it isn't a locker. Within that parameter, it's an excellent unit.

DXJ said:

I talked to an installer that seemed to know what he's talking about and he said that the manual for the Tru-Trac says that if a wheel starts to spin you should STOP, apply brake pressure and then start again.

Click to expand...

That is impossible to do in most situations with a stick shift...

I've had TruTracs F/R for 5 years now and LOVE them. I never got the manual for mine, that is the first time I have heard about stopping and applying the brake. When I have an airborne tire spinning, I'll gently start applying the brake as I gently increase the amount of throttle. I don't think I have ever gone over 1500 rpm while doing this.

I'm a baby on the gas and always have been, that said, I did break the rear (Dana 44) TruTrac about 6 months after getting it installed. It looked like the snap ring holding in one of the worm gears simply fell out of it's bore. The gear dug a nice wide groove around the inside of my axle housing while finishing the trail and driving the 5 hours home. I didn't find out what happened untill I got home and pulled the cover. Drivetrain Direct warranteed it, although they tried to talk me into upgrading (?!?) to a Detriot Locker.

You'll never feel it clunk or make any sound as it engages, to this day I still have too look out the window or ask a spotter if I have any tires spinning freely. The only time it ever failed to lock up was when I tried using 80w140 gear oil in the diffs.

DXJ said:

I'm looking at the newly available Tru-Trac for my 8.25. I talked to an installer that seemed to know what he's talking about and he said that the manual for the Tru-Trac says that if a wheel starts to spin you should STOP, apply brake pressure and then start again. Does it really say that? Is that really needed? He basically said he doesn't recommend them for Jeeps because he says something sounds really odd about that statement in the manual. I would just like to confirm that it really says this (or not).

Is there anything about the design that makes it weaker than other LSDs? I don't mean it's ability to prevent slippage, I just mean will the gears and the way it engages cause mechanical failure or breakage faster than a clutch type LSD? Does it engage with more of a "clunk" or suddeness than clutches?

Thanks.

Click to expand...

You gotta PN for this new TT for the 8.25"

Thanks

like Crash said...

---They are fairly good at taking abuse, and you can get them to lock up pretty tight, so they have always been my favorite LSD.

PN would be- 912A553

Rawbrown said:

like Crash said...

---They are fairly good at taking abuse, and you can get them to lock up pretty tight, so they have always been my favorite LSD.

PN would be- 912A553

Click to expand...

Thank you Rawbrown!!

I have been ready to swap my axle for a while because I wanted a TT, and the only one available was the Auburn(which I love), but wanted something else.

Now, on to finding an 8.25" axle that doesnt drone.

Fergie

Is there any reason why applying the parking brake wouldn't work on a TT?
I used to do this with my old Trash Loc and it worked well.
Just a little easier to manipulate a lever than another pedal.

LSD they are good. If you really need it to lock, they suck. I have one in my front 44, it never lockes when I need it. Hopefully, SOON, I will be changing it out. I dont recomend it for anything other than LIGHT wheeling. If you plan on lifting a tire, dont get it.

Handlebars said:

That is impossible to do in most situations with a stick shift...

Click to expand...

In the rear (8.25)
Stick Shift = Parking Brake Use

I have a D30 Tru Trac....Love it....It isn't a locker, but it is as close as it gets!

I do lift tires...and it LOCKS...IF you ride the brake the right way(hard).

JohnX said:

In the rear (8.25)
Stick Shift = Parking Brake Use

I have a D30 Tru Trac....Love it....It isn't a locker, but it is as close as it gets!

I do lift tires...and it LOCKS...IF you ride the brake the right way(hard).

Click to expand...

It locks because unlike the D35 TT, the D30 TT has a preload that will force it to lock even with a tire in the air.

I can't say anything for the preload (never heard that before), but I do know that if I get one tire in the air it spins bad...But if I hit the brakes, then it locks hard.

How was the handling in 4hi in the sow/ice?

My old lockright(d30) was a pain to drive i nthe snow, and could be unpredictable.

Fergie

JohnX said:

I can't say anything for the preload (never heard that before), but I do know that if I get one tire in the air it spins bad...But if I hit the brakes, then it locks hard.

Click to expand...

Raise one of the front tires while in 2X4.
Try to spin the tire. Mine takes about 20 Ft-lbs to rotate.

Fergie said:

How was the handling in 4hi in the sow/ice?

My old lockright(d30) was a pain to drive i nthe snow, and could be unpredictable.

Fergie

Click to expand...

No idea, I installed a TT in front and back last fall, we never got any snow or ice to speak of.
It feels great off road though. Like it has a lot more traction.

falcon556 said:

Raise one of the front tires while in 2X4.
Try to spin the tire. Mine takes about 20 Ft-lbs to rotate.

Click to expand...

????

I only have a TT in the front...so I'm not sure what you mean? In 2x4 mine won't have ANY affect?

Do you mean spin it by hand?

Fergie said:

How was the handling in 4hi in the sow/ice?

My old lockright(d30) was a pain to drive i nthe snow, and could be unpredictable.

Fergie

Click to expand...

Had mine in the snow...on a very steep paved road (9% grade) and it worked very well...I couldn't tell it was there, but the traction was excellent. I even stopped on the steepest section of the road and tried to spin the tires (not real hard, but I did try). It performed great, nothing dramatic, no noises, and best of all...No tire spin. I also tried it in reverse up the same section of road....perfect traction.

JohnX said:

????

I only have a TT in the front...so I'm not sure what you mean? In 2x4 mine won't have ANY affect?

Do you mean spin it by hand?

Click to expand...

I meant that if you put the TC in 2X4 mode to keep the drive shaft free and then jack up one front tire, normally you'd expect to be able to hand spin the tire. Mine did before TT installation, not after.
A D30 TT has a preload in the Diff that takes a certain torque to overcome.
I think their manual says 30Ft-lbs, mine takes about 20.
If I raise a rear tire with the tranny in neutral, I can hand spin it freely.
The D35 TT is not preloaded.
The D35 TT needs some resistance to engage just like all Torsen style Diffs.
I was told that the Humvee manual instructs light braking when a wheel is in the air. They use 1st generation Torsen in front and back.
I believe that the TT is close to a 2nd generation Torsen.

Cool, good to know....I kind of figured it out after reading it a few more times

Anybody else have these .. Thinking of getting some front and rear ...