Detroit truetrac one wheel slip

[ethrjock]

I just had a shop install a detroit truetrac. Took her to the trac and after 4 passes I had one tire spinning during the burnout and one that did not. I

I started to first notice the car was pulling to the right when I launched her and I just thought that was odd but I have changed a lot of components so I chaulked it up to the new suspension.

After 4 pulls the drivers side tire would not spin during the bunout with the front tires locked with the line lock. I did my usual 3000k rpm 2nd gear dump to get the tires smokey but the left rear did not spin.

Is there something I can do with the car up on blocks and spin the DS manually to determine what might be going on? I thought these detroit truetracs were almost bullet proof. I cant believe she is shot already.

I called my installer and he said there isnt really to install it improperlly where one wheel wont spint but the other one will. I did buy this TT used but it actually looked new.

Any ideas what I can check before I pull the rear cover off and inspect it?

 

[BruceH]

Maybe you already know but just in case I'll mention it. A truetrac has to have dino fluid without friction modifier. Do you know what fluid was put in the differential?

 

[ethrjock]

Royal purple. A lot of guys running royal purple and trurtracs.

I'm open to the possibility that's my problem though.

 

[Brezick]

Just got my trutrac in recently with RP oil. 6 passes so far, no issues. burnouts were all straight on both tires.

 

[stkjock]

Eaton is very clear about this, DINO oil ONLY

 

[ethrjock]

Will the wrong oil cause one side to slip and the other to grab?

 

[stkjock]

Will the wrong oil cause one side to slip and the other to grab?

I would think not

FAQ for Differentials

Truetrac

What kind of oil should I use? Can I use synthetic? Do I need friction additive/modifier?
A quality petroleum/mineral based oil works best in the Truetrac units. We do not recommend synthetic oil. Friction additive/modifier is not required.

Can I use the stock bearings?
In most cases the Truetrac units work with the factory (stock) bearings. The exceptions are: 10 bolt 8.5\8.6 GM axles, the “Performance” Dana 35 & 44 and GM12 bolt with 35 spline axles. No other “special” setup is required.

What kind of break-in is required?
The Truetrac units do not require a break in. The unit’s internals will take a little time (depending on driving conditions) to “seat.” Afterwards there will be a slight improvement in its performance.

When does the Truetrac lock up?
The Truetrac is a helical gear limited slip differential and never “locks up”. The Truetrac operates by transferring power from the spinning wheel to the wheel with the most traction. If one tire breaks traction, the amount of rotation (or spin) is controlled. The torque is then sent to the other tire that still has traction.

I use my car on the street and on the strip, will the Truetrac hold up?
On the street, the operation of the Truetrac will be transparent. You will not know it is there until you need it. In racing situations the unit will apply torque to both tires and launch straight as an arrow, time after time.

How much horsepower and torque will the Truetrac take?
There are many factors to consider when determining if a specific differential will last in your vehicle. Horsepower and torque are important factors. However, the weight of the car, tire height/width, the terrain and suspension are all important things to take into consideration.

For example, a setup that uses street tires will live longer because both tires will break loose and spin before any real strain is put on the unit. But as the tire gets wider, the stress on the unit increases because the traction is greater. When in doubt, the best bet is to call us with your specific application and driving conditions.

Can Truetrac be used in the front axles of full time 4 wheel drive jeeps and trucks?
Yes, it can. You will find will find Truetrac differentials to be very smooth yet effective in either end of your vehicle.

Can I repair the Truetrac if I need to?
The worm gears inside a Trutrac are maintenance free, and do not require regular service. Internal failure usually results in the damage of the worm gear pockets. Therefore, they are not rebuildable.

What is the warranty?
The Truetrac unit is covered for one year from date of purchase against defects in materials and workmanship up to a 38.”

 

[05yellowgt]

Hmm, I had to replace my Tru-Trac once, but it was because a bolt backed out of its housing and the bolt got chewed up by the ring and pinion. The unit still applied power to both wheels though. Does the TT make any noise? It shouldn't. Also, the TT is not a true locker, so if you have 0 traction on one wheel it cannot transfer any torque to the non spinning tire, but you shouldn't be seeing that condition at the drag strip.

 

[tmcolegr]

Is there something I can do with the car up on blocks and spin the DS manually to determine what might be going on?

To verify that the TrueTrac differential is​

properly installed​

, restrict the rotation of the
pinion shaft (by placing the gear shift lever in​

park​

for automatic transmissions, or in reverse​

for manual transmissions), and raise the axle
so that both wheels are off the ground. When
one wheel is turned by hand, the other wheel
should rotate freely* in the opposite direction.​

Check in both directions.

 

[94tbird]

Dino oil only, and a tru trac is not bullet proof. ive killed 2. one in the 8.8 and one in the 9" rear. The only limited slip diff that is damn near bulletproof is a wave trac. and i say this because the only limited slip diff that boasts a 1200rwhp rating and a warranty that COVERS racing and competition use, is the wavetrac.

 

[ethrjock]

94tbird. What were your symptoms when your 8.8 Trutrac broke? I hear no noise, loose parts etc.

 

[LSlayer]

To verify that the TrueTrac differential is​

properly installed​

, restrict the rotation of the
pinion shaft (by placing the gear shift lever in​

park​

for automatic transmissions, or in reverse​

for manual transmissions), and raise the axle
so that both wheels are off the ground. When
one wheel is turned by hand, the other wheel
should rotate freely* in the opposite direction.​

Check in both directions.

Initially when I turn one wheel the other wheel turns the other way. But if I start turning the wheel faster other stops. Is this normal?

 

[05stroker]

Initially when I turn one wheel the other wheel turns the other way. But if I start turning the wheel faster other stops. Is this normal?

I hope so, that is what my new setup does.

 

[ethrjock]

Once I get her off the blocks this weekend after the broken waterpump, pulley, broken hard AC line, broken wiring harness, belt etc from the last track day I will put the rear up and see what happens.

Thanks tmcolegr

To verify that the TrueTrac differential is​

properly installed​

, restrict the rotation of the
pinion shaft (by placing the gear shift lever in​

park​

for automatic transmissions, or in reverse​

for manual transmissions), and raise the axle
so that both wheels are off the ground. When
one wheel is turned by hand, the other wheel
should rotate freely* in the opposite direction.​

Check in both directions.

 

[scramblr]

I killed a TrueTrac as well. Bad wheel hop upon launch and I didn't let off fast enough. Gears whined afterwards and when I had them replaced, upon trying to remove the LPW cover, one of the cap load bearing bolts broke off, so something was out of alignment. Upon installing the gears and diff, it would not spin freely, so put the stocker in there and all was fine. Just replaced it with a new TrueTrac.