Detroit TrueTrac Posi install

edfiero1

Member
I'm trying (for the first) time to DIY swap my peg leg rear end for a TrueTrac. (Not changing Ring Gear or Pinion, so I 'thought' it would be easy. HA. Boy have I got a lot to learn)

So, stupid newb type question. The new unit is in the car, axles and c clips back in. The car is still jacked up, Tranny in Neutral. I rotate each axle and the axle spins, but the ring gear doesn't spin. Next I tried turning the drive shaft (and ring gear). The axles turn in this case, but not with any force. I can easily stop the axle from spinning with my hand while turning the driveshaft. I know the whole idea is that the wheels can spin at different speeds, but I was expecting to have to put some significant resistance on the axle before it would stop turning.

Does this seem normal? I could be paranoid, but it just doesn't seem right to me. I can't figure out any steps that I missed. (other than having a poor gear contact pattern.)

I've looked at about a dozen youTube videos, but most of them stop after reinstalling the carrier retainer and nobody is jacking around with spinning the axles and/or driveshaft like this.
 
That sounds normal. The Detroit Tru-trac works with hour glass shaped gears. With equal pressure on the axles the hour glass shaped gears stay in the middle allowing differentiation. When one axle is loaded the hour glass shaped gears move and get wedged transferring power the the other axle.
You may not be able to apply enough load by hand to make the hour glass shaped gears move.
When rock crawling, I’ve seen one axle (on the front diff) jerk and spin until the driver applies the brakes to load the axles causing the hour glass shaped gears to wedge tighter and walked right up the canyon wall.
If I were street driving a rock crawler or installing a new posi in a canyon carving GN I would choose the tru-trac. It differentiates very well powering through curves (the Detroit Locker drives the inside wheel going through a corner causing unpredictable handling) and doesn’t require special fluid or have clutch plates to wear out. When launching, it locks up very well delivering power to both wheels.
I had a serious trail rig with Powertrax lock rites (they work the same as the Detroit Lockers) and it took a bit to get used to daily driving it through the canyons of northern Colorado.
 
I installed the true track in my GN and like you I thought this was a big$ mistake on the jack stand.
I trusted the advice of a fellow member about getting it.
After driving it I was 100% happy with the results.
Yes on a 4X4 you may need to pump the brakes to transfer lode from a free spinning wheel.
It is fare better than the OE clutch in every driving condition I have put my GN in
 
I'm trying (for the first) time to DIY swap my peg leg rear end for a TrueTrac. (Not changing Ring Gear or Pinion, so I 'thought' it would be easy. HA. Boy have I got a lot to learn)

So, stupid newb type question. The new unit is in the car, axles and c clips back in. The car is still jacked up, Tranny in Neutral. I rotate each axle and the axle spins, but the ring gear doesn't spin. Next I tried turning the drive shaft (and ring gear). The axles turn in this case, but not with any force. I can easily stop the axle from spinning with my hand while turning the driveshaft. I know the whole idea is that the wheels can spin at different speeds, but I was expecting to have to put some significant resistance on the axle before it would stop turning.

Does this seem normal? I could be paranoid, but it just doesn't seem right to me. I can't figure out any steps that I missed. (other than having a poor gear contact pattern.)

I've looked at about a dozen youTube videos, but most of them stop after reinstalling the carrier retainer and nobody is jacking around with spinning the axles and/or driveshaft like this.
yep , thats how these work.
And im very impressed with my True trac.
 
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