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detroit locker not working

Old Aug 15, 2011 | 11:04 PM
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Default detroit locker not working

What will cause a detroit locker to not work at all? Anytime I get one tire off the ground or little traction only one tire spins. Its been like this since I bought the Jeep about and I just pulled the diff cover off to change the gear oil and confirm it actually has a locker.
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Old Aug 15, 2011 | 11:45 PM
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You sure its actually a detroit? Sounds like a Limited slip or a tru-trac action. When Detroits break, usually nothing spins or they both spin........your mileage will vary.
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Old Aug 16, 2011 | 10:24 AM
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99% sure it is a detroit. The guy I bought it from said it had a detroit locker and when I pulled the diff cover off yesterday I looked up a detroit locker online for a chrysler 8.25 and they like identical. I wish I would have taken a pic.
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Old Aug 16, 2011 | 02:41 PM
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Jeremy, when you had the differential cover off did you inspect the lock pin? Also check the bolts that holds the two half's together. Either a broken pin or lose bolts can cause the locker to not work right. It could also be a Detroit Trutrac and not a locker, there is a similarity between them and to many people call any traction enhancing differential a locker.
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Old Aug 16, 2011 | 03:01 PM
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yea, the detroit locker has 8 or so bolts exposed on the non-ring side and the trutrac is more smooth of a case.


Detroit locker
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Detroit Tru Trac
Name:  Detroit tru trac.jpg
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usually when a detroit locker breaks, it takes a shaft with it, and the detroit locker for that axle is rated to somewhere around 800hp. so if it broke, you would know it.
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Old Aug 17, 2011 | 12:48 PM
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Going by the pic I have the tru trac. Does it work differently than most lockers?
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Old Aug 17, 2011 | 01:29 PM
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Originally Posted by jeremy175
Going by the pic I have the tru trac. Does it work differently than most lockers?
Yes, because it is NOT a locker. It is a Limited Slip or posi dif. This means it is basically a tight open dif. More traction than OPEN as long as all the wheels have traction.
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Old Aug 17, 2011 | 02:09 PM
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Ok that makes more sense now. Both wheels need to be on the ground for it to work. Now there are braking tricks and e-brake tricks you can use to make the tru-trac has both wheels on the ground and that will aid when you have one tire in teh air.
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Old Aug 17, 2011 | 03:00 PM
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Originally Posted by 93gc40
Yes, because it is NOT a locker. It is a Limited Slip or posi dif. This means it is basically a tight open dif. More traction than OPEN as long as all the wheels have traction.
Yes, it is NOT a locker. It also is NOT a Limited Slip and posi is a GM term for their LSD so it isn't a posi.

A Detroit TruTrac is a gear driven, torque biasing, traction enhanced differential. There are no clutches as in a LSD so no worn clutches discs to replace. Next to a locker the TruTrac is the best differential for use on a wheeling rig.
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Old Aug 17, 2011 | 03:08 PM
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Ok thanks for the input. I'll try the brake trick next time I have a tire off the ground.
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Old Aug 17, 2011 | 10:47 PM
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Originally Posted by Rock Toy
Yes, it is NOT a locker. It also is NOT a Limited Slip and posi is a GM term for their LSD so it isn't a posi.

A Detroit TruTrac is a gear driven, torque biasing, traction enhanced differential. There are no clutches as in a LSD so no worn clutches discs to replace. Next to a locker the TruTrac is the best differential for use on a wheeling rig.
According to Eaton's website, the mfg of the truetrac, it is in fact a LSD. It's a helical gear driven LSD. Not all LSDs use clutches.
The one I had was about as useful as an open diff. On a light rig with big tires they won't lock up worth anything and it's hard to use the brakes when it's in the front and you're climbing a hill or rocks.
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Old Aug 18, 2011 | 11:48 AM
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Originally Posted by xjmarc
According to Eaton's website, the mfg of the truetrac, it is in fact a LSD. It's a helical gear driven LSD. Not all LSDs use clutches.
The one I had was about as useful as an open diff. On a light rig with big tires they won't lock up worth anything and it's hard to use the brakes when it's in the front and you're climbing a hill or rocks.
Sorry, but there is no slip in the TruTrac, yes it is helical gear driven, but it is a torque biasing differential which is suppose to transfer up to 40% of the available torque. It operates something like a LSD, but it isn't a LSD.
I've also had TruTracs one in the front and one in the back. The one in the front was worthless, the one in the back was less worthless, but neither was a locker.
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Old Aug 18, 2011 | 12:33 PM
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i have one up front, and maybe it is different for auto trans, but mine is a maual and that thing locks up all the time. i have had 1 tire off the ground and it still spun the one on the ground. so it is different for all but i like it and it was un noticed on the street
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Old Aug 18, 2011 | 01:00 PM
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Originally Posted by Rock Toy
Sorry, but there is no slip in the TruTrac, yes it is helical gear driven, but it is a torque biasing differential which is suppose to transfer up to 40% of the available torque. It operates something like a LSD, but it isn't a LSD.
I've also had TruTracs one in the front and one in the back. The one in the front was worthless, the one in the back was less worthless, but neither was a locker.
I dont know for sure but there may be some confusion here on what the slip in LSD actually is. Slip % is the difference in spin rate between one wheel and the other that the locker will allow. if its 40%, it will let one tire spin 40% faster than the other. There most definitely IS slip for an HLSD, its not clutches slipping like in a VLSD but thats not why its called a limited slip anyway
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Old Aug 18, 2011 | 02:00 PM
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Originally Posted by Hoooper
I dont know for sure but there may be some confusion here on what the slip in LSD actually is. Slip % is the difference in spin rate between one wheel and the other that the locker will allow. if its 40%, it will let one tire spin 40% faster than the other. There most definitely IS slip for an HLSD, its not clutches slipping like in a VLSD but thats not why its called a limited slip anyway
Yes, I was wrong. I checked some of my information and although it is actually a torque biasing differential it is also a limited slip.
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