[onick]

Hi guys, bear with me as i'm not too familar with diff internals. I'm going to have my 12 bolt rebuilt, so i'm gonna tear it down, clean, paint, then send to a shop to get setup/rebuilt.

I have attached a 'sequence' to remove the carrier. Please correct me if i'm you see anything i should look out for

1) remove retaining bolt for cross shaft
2) With bolt removed, remove cross shaft to bump in axles to get to c-clips,remove c-clips,remove axles, re-install crossshaft and retainer bolt
3)Remove bearing caps(mark so they go back in the same), remove carrier assembly(shims too). Then remove wheel seals/bearings,ect

I think this will get me far enough so I can thoroughly clean the inside/outide of the housing, then paint,new bushings and send out to get rebuilt.

One more question! My vent is snapped off. Do i just drill out the old one? Where can I get a new one?

Thoughts?

 

[big gear head]

Don't paint it until you get it back. I hate it when someone brings me a painted housing to rebuild. It's not easy to hold one of these when you are working on it, and if it's painted then it's just about impossible to hold it without damaging the paint.

When you mark the caps, don't center punch the left cap. Just mark the right cap. There is no need to mark them both, and the left cap carries more load than the right, so if a cap is going to break it will be the left one. If you punch it then that makes a weak spot on the cap. Just put a light punch mark on the tab on the right cap and put another mark on the housing next to it.

 

[onick]

Ok, sounds good. It will just be primer when they get it. Since I will be using the same Eaton unit, do I need to measure anything before i pull the carrier? I figure if they are re-doing the pinion seals and everything they would have to start from scratch anyway?

 

[big gear head]

Yes, they will have to start from scratch if you are changing gears.

 

[Mike]

Doesn't sound like he's changing gears.

 

[onick]

Doesn't sound like he's changing gears.

Correct, re-using the gears but the pinion has to come out, right?

 

[MEJ1990TM]

What is the trickiest part about setting up a rear end? From my limited experience in just tearing down my 12 bolt I would have to guess it's setting the pinion up. It seems as though getting the ring gear situated wouldn't be difficult, it'd just be monotonous. Since I don't know I figured I'd ask.

 

[big gear head]

Yes, setting the pinion depth is the hardest part. If you are keeping the same gears then they might want to use the same shims as a starting point. Chances are that these shims will be correct, or close.

 

[tlowe]

Before pulling that rear apart, you really need to blueprint it. This is simple and will save whoever a ton of time.
Clean the gears with brake cleaner while it is still together. Mark with gear marking compound and rotate the carrier both directions a few times. Take digital pics of both coast and drive side of ring gear. store these for future reference. Measure the Backlash and record. When tearing down take notes of each carrier shim and the pinion shim. These notes will help you put this rear back together much faster and right. Tom

 

[onick]

Easy enough, will do.

Before pulling that rear apart, you really need to blueprint it. This is simple and will save whoever a ton of time.
Clean the gears with brake cleaner while it is still together. Mark with gear marking compound and rotate the carrier both directions a few times. Take digital pics of both coast and drive side of ring gear. store these for future reference. Measure the Backlash and record. When tearing down take notes of each carrier shim and the pinion shim. These notes will help you put this rear back together much faster and right. Tom

 

[big gear head]

I agree with Tom on this. You need reference photos of the pattern and you need to know what the backlash is so that it can be set the same again. I do this whenever I'm replacing bearings and using the same gears again, or just changing the differential.

 

[onick]

Ok, here's what I came up with. The only item i didn't mess with was the pinion. I think i flubbed up the gear marking as well as it is hard to see. It looks like the back lash on the used came out to around .013. My first time checking back lash, pretty easy actually. I also pulled and bundled up the driver side shims and passenger shims. I hope this will be enough to aid the shop in the rebuild.

 

[big gear head]

When checking the backlash you must be sure that the pinion can not move any at all. If the pinion moves even very slightly it will give you a false backlash reading, which can screw up the set up when putting everything back togehter.

When marking the gears use an axle to turn everything. Just stick an axle in there and turn it everal times in both directions and your pattern will be clear and easy to read.

 

[onick]

Thanks for the tips! I had the pinion locked down very well so it wouldn't budge. It's all apart now so that will be good to know for next time.