gear install question

[mjtjnj]

hey-

I got the rebuild kit for my amc20, and I have a trac-loc carrier, rebuilt, all set to go in. I have a buddy who is a mechanice who is going to show me how to do it. The kit I bought came without shims, and he said that if we weren't changing out the carrier, he would just re-use the same shims. The new carrier COULD change things, he said, so I'm just wondering if anyone knows something about this?

 

Thanks

Tom

[JeepcoMJ]

buy a shim kit.

[CWLONGSHOT]

Agreed, you are going to need them.

 

If you get the master install kit for that axle it should have shims too, IIRC.

 

CW

[jpdocdave]

the title says gear install, so i'm assuming you are installing new gears (or new to that axle)

 

don't let anyone help you that says they can just reuse the old shims. thats my only advice.

[comanchedude]

the title says gear install, so i'm assuming you are installing new gears (or new to that axle)

 

don't let anyone help you that says they can just reuse the old shims. that's my only advice.

 

 

What jpdocdave said.....

I have done new gear sets in 5 axles and can say you will not be able to get correct setting on new gear set with just the old shims. (now if you just rebuilt the limited slip unit and didn't change the gears then you would be ok. make sure you have extra crush sleeve for the AMC20 as you may not get the correct pinion pre-load your first try.

[CWLONGSHOT]

I'm no expert, but I have never had a problem with old shims. I mean, to my mind it's a piece of hardened steel, its use is simply its thickness, used to take up space. If it wears any it becomes thinner and worst case you would need another shim to make up the difference frm the wear. IMHO, a shim is a shim, some are thick others thin. Weather one is .010 new or was once .011 and now is .010 because of wear, they will both take up .010 in space.

 

Now if you meant that using the exact set of shims for every carrier because it was good in the last one. I agree with you. You need to set up every different carrier you install. But for what your doing, if I understand correctly. You should be fine reusing the shims you have. You just may need to add or omit some of them to get the proper preload on your bearings and pattern on your gears.

 

CW

[Eagle]

And don't forget that if you are regearing, the new pinion gear has to be set for depth, and that is controlled entirely by shims. It is possible that the old shims might be right ... but highly unlikely. You need a shim kit.

[mjtjnj]

Thanks, yeah, I am going to buy a new shim kit. This guy does know what he's doing, I was just trying to do some research. The kit I bought did come with some shims, the pinion bearing, the carrier bearings, races, etc., a Timken kit.

 

I'm trying to find the axle bearings/seals. Guy at the local parts store looked it up for me and it listed (Federal Mogul) a d35 and d44 for a 1986 Comanche :fs1:

 

He thought it might be that they meant the heavy duty axle. Going to press off the old bearings and find out if they're the same. If someone already did this, and knew the part #s, that would really help.

 

Tom

[64 Cheyenne]

Lots of times I order for an XJ instead of a MJ. Get a lot less questioning that way.

[wannabeMJ]

do you have a used set of bearing??

that came realy handy when we did my front spool

or once you get yours out (if still good) just grind the interior with a dremell so you can slide them on easy

 

I was also missing shims and its a pain to get a friend to come give you a hand on a saturday morning just to realize that you are missing part to finish the job

 

as for your crush sleeve on the pignion use a cumulativ torkwrench its a lot easier that way then to try to get the right tork the first time or order 3 or 4 crush sleeve

[TrailReadyMJ]

Thanks, yeah, I am going to buy a new shim kit. This guy does know what he's doing, I was just trying to do some research. The kit I bought did come with some shims, the pinion bearing, the carrier bearings, races, etc., a Timken kit.

If you got the full timkin install kit, it's doubtful you will need extra shims, can't hurt though.

I'm trying to find the axle bearings/seals. Guy at the local parts store looked it up for me and it listed (Federal Mogul) a d35 and d44 for a 1986 Comanche :fs1:

 

He thought it might be that they meant the heavy duty axle. Going to press off the old bearings and find out if they're the same. If someone already did this, and knew the part #s, that would really help.

 

Tom

I haven't dealt with the MJ D20, but it was the HD axle option at the time. I'm not sure, but it mat have the same bearings and seals as a CJ D20 of the same year? I know CJs used 2 piece shafts where MJs are 1 piece, so they are a bit different, but it may give you something else to compare to.

 

Lots of times I order for an XJ instead of a MJ. Get a lot less questioning that way.

That works great for most things, but they never put the D20 in an XJ.

[jpnjim]

The AMC M20 was only on 1986 MJ's, so make sure they're looking up the right year.

 

They could look up the full size Jeep application, or even the AMC car application to get part numbers:

ALL full size AMC's: Matador, Ambassador, Rebel, Classic, etc got the AMC 20, regardless of which engine they used, other AMC's based their rear axle on which engine it got (AMC 7 9/16", AKA Dana 35 for 4's & 6cyl, Model 20 for V8's.