I have a 2000 Blazer LT and as a birthday present to me, the pinion gear bearing blew apart and screwed up the pinion gear. I purchased a new pinion gear and bearings and a mechanic I use all the time on this blazer took everything apart. He replaced the pinion gear along with the bearings and put everything together. Everything looked great and all the gears moved manually until he bolted the brackets to the housing. He couldn't get the pinion gear to move manually. But when he unbolted the brackets, everything moved manually. One thing to note, we did not replace the ring gear that came with the pinion gear because it looked undamaged and since everything is supposed to be the same gear ratio 3.42 we figured it would work with the old ring gear. The truck moves smoothly in reverse, but locks up in drive. It's obvious we did something wrong here, but with the great wisdom of the members here, I'm hoping someone can enlighten on fixing this situation.

Thank you

 

sounds like you didn't get the bearing preload right with the crush sleeve ....

 

Odat, thanks for your reply, but what do you mean? Which bearing and what is preload all about. Okay I am not that mechanically inclined, what is the "crush sleeve? I've worked on 60 & 70 model cars and trucks in my day, but the vehicles today just baffle me, that's why I found a "mechanic" to work with me who is supposed to know all this. Since he's on vacation, I'm trying to find the solutions before he gets back so I can stop burning money on this. I know the pinion gears has two bearings that go onto it, one large and one smaller in the middle. Thanks again.

 

Inbetween the two pinion bearings there is a collar called a crush sleeve. As torque is applied to the pinion nut it collapses and as it does it sets the depth the pinion sits in the housing for gear back lash { back lash - how the pinion and the ring gears teeth contact each other }
It also sets how much pressure the two bearings have on them while sitting in the races.
You also have shims on either side of the ring cage bearings - the shims set how far the ring is set sideways for ring contact to the pinion gear teeth.
Sorry but this nothing new, diffs have been set up this way prob since day one .....
Oh and they can be a royal PIA to do .....

 

Odat, Now that makes sense to me. What would the solution be to my situation? Pull everything out and start over again? I knew I should have bought a used differential from salvage. Thank you for this information, now I understand why you are classified a "Super Member".

 

You can't replace the pinion without replacing the ring gear. I'm not even sure how you were able to buy it without the ring gear. Even if you can get it to drive, its lifespan will be measured in minutes.

 

Tom A., No I did receive the ring gear with the pinion gear, but we didn't install the new one because the old one looked good still. I didn't know it HAD to be replaced. But that makes sense. I had a feeling the ring gear had to be replaced since it was in the box with the pinion gear, but my mechanic said no, because it looked fine. I guess it's time to find a mechanic who knows something more about differentials.

Thank you.

 

I would definitely agree with that statement.

The good news is, you probably haven't done any damage to the new pinion. The bad news is, you need to go through the whole setup procedure for a new gear set, which is fairly complicated, time-consuming, and best left to a professional. Good luck!

 

Yes Tom A., I think you are correct. I am looking for a repair shop now to tow my Blazer to for repair.

Thanks again.

 

You're welcome. Sorry if I came off a little harsh.