Detroit Truetrac. This with the trans in Park, driveshaft is not turning. This is the passenger side. I can turn the other side too, but it is a lot stiffer. Good layer of fine metal sludge on the magnet considering it was just cleaned a few miles ago.

Video

 

That might not be the best differential for the amount of power you're putting down. Google it and you'll see what I'm talking about.

 

Does the true trac have clutch packs?

 

No clutches.



A local gear shop owner was telling me that the Truetrac was not good for drag racing because it has a tendency to lock/unlock. Didn't mention anything about it being weak when he was checking out my truck at the track.

I was thinking that the one axle was spinning freely and the other was not turning because it was so hard to turn that one. Both sides are connected via the helical gears so I though something could be broken. Took it apart to inspect and didn't find any broken parts. The helical gears on the left side do feel a little rough though and there appears to be some twist in the splines of the left side axle. It may have already looked like that the last time I took it apart.

Cleaned it up and put it back together. Both sides are spinning freely now(opposite directions).

Right side helicals



One of the left side helicals



Side gears and helicals both sides



Left axle (Yukon Gear)



Ring gear

 

In looking at your ring gear, besides that it's destroyed, the contact pattern seems too far to the heel.
The axle's on it's way out, I would not put that back in.
You're getting good traction apparently. You might consider making your next gear set a numerically lesser ratio - that will reduce the torque all these components see.

 

I had the same thing with my trutrac. Did you see the thread I started? I believed it was due to the plug that holds the axles out not being tight enough. You basically want to have to tap that plug in place lightly.

Is your damage like this? BTW I'm still running that trutrac after making sure everything was tight.

https://www.performancetrucks.net/fo...s-dust-518911/

 

I did not notice any wear in that area. I always felt that spacer was way too loose in the 9.5 as well. Had a Truetrac in my original 8.6 and the spacer was snug.

 

Current gearing is 3.73. Any street-friendly diff that will survive?

 

I think the pattern looks very similar to the initial setup. Found this old pic from 9.5 build threads.
https://www.performancetrucks.net/fo...lanche-421388/

http://chevyavalanchefanclub.com/caf...,101041.0.html