Ok so I'm doing some gears on a Ford 8.8 for a friend and when I went to crush the sleave to set preload to where it's needed, minutes later the preload increases. It went from 22 or so, as I had set it, to like 35 in 5 minutes without me even touching it. What is going on here? Someone please help as it's frustrating and I'm running out of crush sleaves.

 

Holly crap! I just checked it again and it's past around 60 inch pounds! I did not touch it.

 

Are you using new bearings?

 

Yes I am.

 

And you do have the carrier out of the housing correct?

 

Of ocurse. The second attempt with a new cruch sleave was the same. I left it alone and waited to see if it did it again. Sure enough, well over 60 inch pounds after I set it to the 22 it required. This was just the pinion preload. No carrier.

 

Is it a Ratech crush spacer? You might need to get a GM spacer. I had a few Ratech spacers split on me. They were for the 12 bolt, but you could have something similar going on. I haven't run into this problem before. Let me know what you find so I can keep an eye out for this same problem.

 

I was actually thinking og getting a spacer to hopefully fix this problem. I'm gonna get a few more cruch spacers and play around with the preload. Maybe start at with less preload and see if it swells up. I will def post my findings. Thanks guys.

 

Did you put any gear oil in the bearings before you installed them?

 

Yeah, just a bit, but will that really matter. What can cause preload to just swell up like that? I've built a few 10 bolts before and never had a problem like this. I do love how my Camaro's Ratech solid spacer installed without a hitch and to this date my rear is fine. Leave it to Ford, right? JK lol

 

My SWAG is that the crush sleeve metallurgy isn't correct. And it is continuing to crush after you torque the nut down. That is about the only way the preload would increase over time.

Which means that there is probably a whole batch of bad crush sleeves. Because of that best bet is to go right to a spacer set up.

Note that I've never seen or had the preload increase over time either. Once set, it stayed at that setting.

RBob.

 

Those were my thoughts exactly. I do have one more crush sleave that came with the Motive Gear master rebuild kit my friend gave me. I didn't use because it seemed a bit tall and the bulge where it "gives" to crush wasn't, well, bulgy enough compared to the sleaves I've seen. So, I used the Napa brand sleaves I told my friend to get as a back-up. Both did the same thing. If this one last sleave doesn't work out, although I have a feeling it will if RBob's theory and mine are correct, I'll just use a spacer, set it and forget it.

I'll keep you guys posted for sure. Thanks again, guys!

 

I've got a solid spacer kit on the shelf if you need one.

 

Thats awesome, Freddie. I will def let you know if I end up needing the spacer. I got caught up with somestuff today at home, so i will give the last crush sleeve a try tomorrow. Thanks again!

 

Guys,

It indeed ended up being a bad batch of crush sleeves. The sleeve I used from the master rebuild kit from Motive worked out great. It retained the preload I had set. A strange problem indeed. I'm thinking of contacting the manufacturer of the bad sleeves to let them know what happened. I still have the packaging, so maybe there are batch numbers on them I can let them know about...maybe.

I can't say I'm a fan of this Motive Gear shim kit. The pinion shims I got are as follows: .019, .028, .029, .038, .039, and .040. As you can see, the shim pack is very limited. The closest I could get to the perfect center was with the .029 shim. I needed a good .002-.003 more to hit it right on, but the gears should be OK with the pattern I got. the .038 shim was way too close for comfort. Backlash and preload are dead nuts. Just letting you guys know in case you're thinking of this brand gear set.

Thanks for all the help, fellas!

Mike