Front DTT

[ktmrider]

I installed a front DTT when I changed axles. I had it up on the rack and reached over and turned one of the front wheels and the other one turned the same direction. I thought the DTT would work like an open diff and the other wheel would turn the opposite direction. I have a DTT in the rear and that's what happens when you turn one wheel with it off the ground. I looked at the Eaton website and it is supposed to work like a open diff. I could have sworn I checked that after we installed the diff. There is no noise and the DTT works offroad. The only thing I noticed before was it pulled hard after the install but I swapped tires and that went away.

 

[tjkj2002]

It's a LSD,your front is operating normally but the rear is not.

 

[cplchris]

It's a LSD,your front is operating normally but the rear is not.

I thought the 8.25 DTT should work just like an open diff until power is applied (accelerating)...where as the D30 DTT has a pre-load of like 100 or 150 ft/lbs so it functions like a normal LSD. I don't doubt your knowledge but that was my understanding, I still have my dtt's in the boxes so I will check the manuals that came with them from eaton.

 

[tjkj2002]

I thought the 8.25 DTT should work just like an open diff until power is applied (accelerating)...where as the D30 DTT has a pre-load of like 100 or 150 ft/lbs so it functions like a normal LSD. I don't doubt your knowledge but that was my understanding, I still have my dtt's in the boxes so I will check the manuals that came with them from eaton.

A DTT is a DTT,all have the same pre-load as they are all LSD's.




You have to buy a selectable locker to have that "open diff" action then "locked".

 

[cplchris]

Detroit Truetrac® Function Check
Manual test

Step One
With the engine turned off and wheels chocked, raise
Truetrac-equipped driving axle(s) until all tires are out of
contact with any surface. Check both hand and foot
brakes for possible drag caused by improper
adjustment. Place the transmission in gear or park
so that the DRIVE-SHAFT IS LOCKED AND
DOES NOT ROTATE.

Step Two
While turning one wheel, the other should rotate in the
opposite direction. Units with preload will have greater
resistance to turning. Units without preload will appear
to have a higher internal gear lash (tires will feel more
loose during initial rotation). However all units actually
have similar lash values.

Step Three
Verify correct operations during road test. Use the invehicle
test shown on the next page.

this is copied directly from the eaton owners manual....I guess we should tell eaton that they got it all wrong?

KTMrider, make sure your front driveshaft is not spinning. if you have any concerns about the DTT, I would recommend contacting eaton.

 

[CactusJacked]

Detroit Truetrac® Function Check
Manual test

Step One
With the engine turned off and wheels chocked, raise
Truetrac-equipped driving axle(s) until all tires are out of
contact with any surface. Check both hand and foot
brakes for possible drag caused by improper
adjustment. Place the transmission in gear or park
so that the DRIVE-SHAFT IS LOCKED AND
DOES NOT ROTATE.

Step Two
While turning one wheel, the other should rotate in the
opposite direction. Units with preload will have greater
resistance to turning. Units without preload will appear
to have a higher internal gear lash (tires will feel more
loose during initial rotation). However all units actually
have similar lash values.

Step Three
Verify correct operations during road test. Use the invehicle
test shown on the next page.

this is copied directly from the eaton owners manual....I guess we should tell eaton that they got it all wrong?

KTMrider, make sure your front driveshaft is not spinning. if you have any concerns about the DTT, I would recommend contacting eaton.

No, they didn't get it wrong, it's physically impossible for the wheels to rotate in the same direction when the driveshaft is in a locked position. Put the transmission in neutral, where the drivfeshaft can turn, and you'll find that the wheels will then rotate in the same direction.

 

[cplchris]

No, they didn't get it wrong, it's physically impossible for the wheels to rotate in the same direction when the driveshaft is in a locked position. Put the transmission in neutral, where the drivfeshaft can turn, and you'll find that the wheels will then rotate in the same direction.

well from the sound of it KTMrider has the jeep in the air with the t-case in 2wd and the trans in park. which would give the result that he described, TJKJ immediately told him there is something wrong with his DTT. obviously with the driveshaft freely rotating the wheels will turn the same direction when one is rotated, but with it in 2wd and in park the rear driveshaft can't rotate while the front can...meaning the DTTs are functioning just fine.

 

[CactusJacked]

TJKJ probably said that, because the way to check for an LSD (wheels turning in same direction) is with the trans in neutral. The OP didn't indicate that he was apparently not checking it the right way (trans in park), hence the rear wheels turning opposite directions, giving the appearance of an open diff.

 

[Hockeygoon]

Not meaning to hijack the the thread but how hard/ expensive is it to install a DTT?

I love having LSD axles on my old Bronco and can go twice as far with it as I can my stock Liberty.

 

[ftaa]

couple thousand... may as well do gears while yer in there.

 

[CzarKJ]

Not meaning to hijack the the thread but how hard/ expensive is it to install a DTT?

I love having LSD axles on my old Bronco and can go twice as far with it as I can my stock Liberty.

was 800 with a full rebuild of the rear for me. Just for the install.

 

[Hockeygoon]

See an advantage of only installing it only the front end instead of the rear axle?

 

[tjkj2002]

TJKJ probably said that, because the way to check for an LSD (wheels turning in same direction) is with the trans in neutral. The OP didn't indicate that he was apparently not checking it the right way (trans in park), hence the rear wheels turning opposite directions, giving the appearance of an open diff.

A functioning LSD you should not be able to turn either tire when the driveshaft is held in place(trans in "P").

 

[cplchris]

A functioning LSD you should not be able to turn either tire when the driveshaft is held in place(trans in "P").

well I guess that settles it, eaton got it all wrong.

 

[tjkj2002]

well I guess that settles it, eaton got it all wrong.

I have personal experience,not saying they don't know but they could have worded that wrong.Happens a lot.