Rear Diff Carrier

[OuachitaMtnMan]

How tight should the fit the fit be (side to side) when installing? I understand that each side is shimmed for gear pattern to locate the ring gear left to right... I'm doing this by myself and having a helluva time keeping both races on, getting shims in and caps installed.. does it usually take 2 people? Currently I've got both of the carrier bearing caps started - one finger tight with the factory shim in that side (pass). When I take the left cap off I can't get the factory shim in? Maybe the Detroit is slightly longer than the g80 carrier (thousandths)? Should I try inserting the factory shim on Ring gear side first and passenger side 2nd? Oh yeah it's a 84 K10 with GM 10bolt/8.5" ring gear/28 spline c clips with drum brakes - AAM 4:10 and Detroit Locker going in. Any advice would be appreciated!

 

[OuachitaMtnMan]

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[Honky Kong jr]

They don’t just fall in and it’s doubtful the solid factory shims will hold true to the new carrier. Your carrier didn’t come with a whim kit? Are these new gears or used?

 

[OuachitaMtnMan]

They don’t just fall in and it’s doubtful the solid factory shims will hold true to the new carrier. Your carrier didn’t come with a whim kit? Are these new gears or used?

Yeah I have to the "master install kit" that came with bearings shims pinion sleeve etc. Brand new gears.. I don't know how square the carrier is sitting while I'm trying to do this - the tapered race moves over in the way the if I push too hard to keep it where it should be while sticking the shim in

 

[Honky Kong jr]

Yeah I have to the "master install kit" that came with bearings shims pinion sleeve etc. Brand new gears.. I don't know how square the carrier is sitting while I'm trying to do this - the tapered race moves over in the way the if I push too hard to keep it where it should be while sticking the shim in

It’s all kinda gotta go in at one shot. Did you crush the pinion sleeve to the proper turning torque? That needs done properly before the carrier goes in.

 

[crazy4offroad]

Honestly this is a whole lot easier with the axle off the truck. You can have the opening pointing up and drop it in, about like how changing a crankshaft in an engine is 1,000x harder while in the truck vs on an engine stand, trying to push it up from the bottom instead of dropping in. I usually mic the old shims and use new ones just to have that nice slick new machined surface. Put the carrier with races in, push one side's shims in and put a bearing cap on it loosely, but leave the cap off the other side. Then use a pry bar (screwdriver looking pry bar with a bend in it) to push the bearing race over enough to jam in the shims for the other side. And I'm by no means making it sound easy. Just take your time, pry one side of the race then the other till you can walk it in. You may even want to lightly tap the shims with the plastic handle of the pry bar. If you have more than 2 shims going in your last side, you can get 2 shims started but not all the way in, then you can spread them and push the middle shim(s) between them. WD-40 is your friend!

 

[Honky Kong jr]

Ok I’m out Crazy’s here. He will be way more help then I will be and already has.

 

[OuachitaMtnMan]

It’s all kinda gotta go in at one shot. Did you crush the pinion sleeve to the proper turning torque? That needs done properly before the carrier goes in.

Right now I have the old sleeve on the new pinion for setting the gears. I bought an extra pinion bearing & opened up the bore so it's a slip fit & will put the new bearing that came with the kit in once I have the pinion shimmed. Never done this before it's all new to me

 

[OuachitaMtnMan]

Honestly this is a whole lot easier with the axle off the truck. You can have the opening pointing up and drop it in, about like how changing a crankshaft in an engine is 1,000x harder while in the truck vs on an engine stand, trying to push it up from the bottom instead of dropping in. I usually mic the old shims and use new ones just to have that nice slick new machined surface. Put the carrier with races in, push one side's shims in and put a bearing cap on it loosely, but leave the cap off the other side. Then use a pry bar (screwdriver looking pry bar with a bend in it) to push the bearing race over enough to jam in the shims for the other side. And I'm by no means making it sound easy. Just take your time, pry one side of the race then the other till you can walk it in. You may even want to lightly tap the shims with the plastic handle of the pry bar. If you have more than 2 shims going in your last side, you can get 2 shims started but not all the way in, then you can spread them and push the middle shim(s) between them. WD-40 is your friend!

Thanks for the advice! I have a screwdriver for door panel type fasteners that I'll try with wide end and a bend for prying. The trucks on a tandem axle trailer and the diff is pointing slightly upward due to ORD shackle flip. If I do another one it won't be under the truck!

 

[OuachitaMtnMan]

I got the pinion nut tight enough so the yoke has no slop and I can spin the pinion but it won't stay spinning (before I put the carrier in). Sound right?

 

[crazy4offroad]

Yeah if you're where you're at for checking mesh pattern. As long as you have no in/out movement and spinning the pinion with your fingers it stops when you let go you should be golden.

 

[nwalk7800]

Setting up the carrier is fairly complex task. If you don't get the backlash and preloads set correctly you'll ruin your gears in no time. Here is a nice guide from US Gear that I think is very thorough.

 

[OuachitaMtnMan]

Setting up the carrier is fairly complex task. If you don't get the backlash and preloads set correctly you'll ruin your gears in no time. Here is a nice guide from US Gear that I think is very thorough.

That's actually the guide I'm using! The master install kit was USA standard gear brand and came with a booklet. One thing that stood out to me was on page 8 the paragraph titled Important Pattern Information; it says to only concentrate on how the pattern relates to the ridge and valley of each tooth - not how it relates to the toe & heel...

 

[OuachitaMtnMan]

I checked the backlash first with a magnetic base dial indicator. The initial backlash was .006"-.007". After having a hard time getting the side shims in I was amazed that it was anywhere close to spec. (stuck the indicator back on there to take a photo after I marked the gears).

I painted the gears and rotated the painted ring gear teeth around to the pinion - then rotated the carrier 1/4 turn each direction 3 or 4 times by grabbing the ring gear.

How does this pattern look?? Some papers that came with the ring and pinion set said a 2cut gear would produce a different pattern than a 5 cut gear.. Im not sure which I have..

I know just enough to be dangerous lol, but if I focus on the drive side only it seems the pattern is a shade high on the tooth (so another shim behind the pinion bearing to bring it closer).

I don't know how to approach the toe-to-heel difference in the drive and coast sides... Backlash is pretty good now, so use the same shims but take some from one side and move to the other?
The drive side seems acceptable (although a little towards the heel), and the USA gear setup guide says not to attempt to correct toe-to-heel variations because it will lead to frustration?? Something about the housing dimensions when it was built/machined effects toe-to-heel and that can't be fixed with shims?

So I don't know whether or not to mess with the carrier shims when I take it out to put the extra pinion shim in..

Any input on toe-to-heel pattern adjustment?

 

[OuachitaMtnMan]

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