8.75 Detroit locker normal?

[bricud]

Hey folks, I just put in a 8.75 rear end after rebuilding it. Has new gears, all new bearings, new Dr Diff axles. I put in a sure grip from Detroit locker. Probably made a mistake by buying the Detroit locker used from a juy that said it was barely used. Although the old ones looked fine, I did put new bearings and races on it. After putting in the rear end, I noticed I can rotate the axle about 4.5 deg (measured) with nothing else moving (the other side or pinion). Is this normal? No, this is not the backlash. It is set at .007". I'm assuming it is the posi unit that allows slight rotation but I wanted to make sure it is not a problem before I find out something bad on the road. I'm not an expert by any means on these so any input is helpful. I made a video but can't seem to upload it. Also, I put in a 3150 pinion yoke that came with the u bolts for the u joint. Can these be overtightened? I couldn't find a definitive answer on this.

Thanks,

Brian

 

[Mtrhead]

I thought that was a Ford 9-in thing didn't even know they had them for 8.75 Rears...should sound clunky

 

[Dana67Dart]

If it's a real Detroit locker, it is a ratcheting mechanism. Like a ratchet wrench.

If one wheel has to go faster than the other as it speeds up it ratchets till the other wheel matches speed.

Then when both wheels are going the same speed they work more like a spool zero slippage.

It should make a distinct noise as the car turns a tight corner.

 

[Big.J.007]

The true detroit lockers are 100% mechanical as shown below:

 

[Big.J.007]

The one you show purchased is the electronic version that loads and unloads based on the switch being either on, or off..

 

[Dana67Dart]

The one you show purchased is the electronic version that loads and unloads based on the switch being either on, or off..

That's the box, we don't know what the PO actually has.

 

[72bluNblu]

If it’s an E-locker it may act differently if you haven’t connected it to power. And obviously it’ll act differently if it’s engaged or not.

Have you tried calling Eaton? Or DoctorDiff? You could send Cass an email, he may have an idea.

 

[Bobzilla]

I have a bunch of years and miles on a Detroit Locker in a 9 inch rear end and my brother has a lot of years and miles on a Detroit Locker in an 8 3/4. Between those two I have never heard the noises people talk about. There is a distinct amount of "play" at times because of the way it has to move a little before it can lock in and I think I feel driving as well, but no noise. Maybe that noise is more in very tight turns when accelerating too hard. Normal parking lot maneuvering it does not feel like any binding at all. Really a nice unit for street strip cars.

 

[B3422w5]

I have had everything rear end wise over the years. I am a street strip guy, more strip.
The only thing I have never liked was the Detroit locker. I had one for a while on a 9 sec car. When you would back out of the throttle at high speed on the street, it always made the car squirrelly. Creepy.
Went to a spool and never looked back. For a more street type deal, the clutch type sure grip is nice too

 

[bricud]

Thanks for your input. I will try this one and see if I like it. But I like the experience you all bring. Sounds like the play may be normal but I'll call Eaton about it.

Thanks