Model 20 Axle Swap and Gear Change Help

[Canadian CJ 7]

Today, I was told by a mechanic that my rear seal is leaking and that I could have rear end failure if I don't get it looked at. I guess I will be doing the axle and gear swap sooner than expected. I currently have 273 gears in my Model 20 and I want to change them to 355. I believe I have to change the carrier on the Model 20 if I make a higher gear ratio swap where can I find a carrier? I don't want a posi or locker because I drive mostly on the street. I believe my model 30 front axle won't need a carrier if I keep it 355 and under. Any help would be appreciated.

 

[IOPort51]

are you going to do this or are you paying someone to do it?

Today, I was told by a mechanic that my rear seal is leaking and that I could have rear end failure if I don't get it looked at. I guess I will be doing the axle and gear swap sooner than expected. I currently have 273 gears in my Model 20 and I want to change them to 355. I believe I have to change the carrier on the Model 20 if I make a higher gear ratio swap where can I find a carrier? I don't want a posi or locker because I drive mostly on the street. I believe my model 30 front axle won't need a carrier if I keep it 355 and under. Any help would be appreciated.

 

[Canadian CJ 7]

are you going to do this or are you paying someone to do it?

Hey IO, it's beyond my mechanical abilities, so I am going to have pay someone to have the work done for me. I went to a shop today and the mechanic said he was fine with me getting all the parts and he would install it at his hourly rate. I buy all my jeep parts in the US and have them shipped to a US border town close to me and pick them up. Jeep parts are so expensive in Canada that no one can compete with US. I just want to make sure I need a different carrier for my model 20 before I try to track one down. Parts I will need and correct me if I am wrong or missing anything.

1. One Piece Axle Kit (Moser or similar quality brand)
2. Ring and Pinion 355 gear ratio for the AMC Model 20
3. Possible Carrier for the AMC Model 20 going from 273 to 355.
4. Ring and Pinion 355 gear ratio for Dana 30 front end, I believe carrier will
work up to 355 ratio from 273.

Am I missing anything? If I need a Carrier do axle or gear manufactures make an open carrier or do I have to find a old Model 20 that had taller gears and use a used carrier, not sure what my options are.

 

[IOPort51]

Have you checked to see if you have an open differential now?? If you need a carrier the cost of a rather mild Limited slip will not be much different from the new open carrier. I do not recommend going with used, too much of the cost is in the labor and that will go down the drain if the used carrier takes a dump on you. I would suggest you spend some time with the gear house catalogs and do a bit more research on this. Unless the gear lube is running out faster than you can put it in you are not in an emergency situation.
Do this at your convenience not the mechanic's

Hey IO, it's beyond my mechanical abilities, so I am going to have pay someone to have the work done for me. I went to a shop today and the mechanic said he was fine with me getting all the parts and he would install it at his hourly rate. I buy all my jeep parts in the US and have them shipped to a US border town close to me and pick them up. Jeep parts are so expensive in Canada that no one can compete with US. I just want to make sure I need a different carrier for my model 20 before I try to track one down. Parts I will need and correct me if I am wrong or missing anything.

1. One Piece Axle Kit (Moser or similar quality brand)
2. Ring and Pinion 355 gear ratio for the AMC Model 20
3. Possible Carrier for the AMC Model 20 going from 273 to 355.
4. Ring and Pinion 355 gear ratio for Dana 30 front end, I believe carrier will
work up to 355 ratio from 273.

Am I missing anything? If I need a Carrier do axle or gear manufactures make an open carrier or do I have to find a old Model 20 that had taller gears and use a used carrier, not sure what my options are.

 

[Canadian CJ 7]

Have you checked to see if you have an open differential now?? If you need a carrier the cost of a rather mild Limited slip will not be much different from the new open carrier. I do not recommend going with used, too much of the cost is in the labor and that will go down the drain if the used carrier takes a dump on you. I would suggest you spend some time with the gear house catalogs and do a bit more research on this. Unless the gear lube is running out faster than you can put it in you are not in an emergency situation.
Do this at your convenience not the mechanic's

IO, it's an open carrier, do you know of any company's that make a mild Limited slip? The mechanic said it's weeping and watch dusty roads or might have problems, he very familiar with CJ's having owned eight of them, but he is not doing the work. I just got AAA coverage just in case I break down. I might just get the axles done for now and change the gears later once I have done a bit more homework, is it wise to do this or do the whole thing. Like you said it's not currently an emergency situation. I might order the axle kit and have it on standby in case I spin a hub.

 

[Old Dog]

You DO need a different carrier for the 20, I'm not sure about the 30 though.
I'm wondering why you would not want a Limited slip.

You can go ahead and do the axles now, and do the gears later it shouldn't matter. You should be able to do the axles yourself.

 

[Canadian CJ 7]

I would like a Limited slip, if it's close in price of a open carrier for sure, make sense. If it's twice as much then that's a different story. I am looking for manufacturers of Limited slip for the 20. Does anybody know of any manufactures. I am looking to begin somewhere.

 

[priceg]

The AMC lock track diff is the cheapest Limited slip diff I know of. They retail around $350

 

[Old Dog]

I would like a Limited slip, if it's close in price of a open carrier for sure, make sense. If it's twice as much then that's a different story. I am looking for manufacturers of Limited slip for the 20. Does anybody know of any manufactures. I am looking to begin somewhere.

When I first built my jeep for the street I had one of these.Auburn Gear Pro Series Differentials - JEGS I was very happy with it and only changed it for a locker when I started playing in the rocks.
I still have it and would sell it if you are interested.

 

[Canadian CJ 7]

When I first built my jeep for the street I had one of these.Auburn Gear Pro Series Differentials - JEGS I was very happy with it and only changed it for a locker when I started playing in the rocks.
I still have it and would sell it if you are interested.

Hi Old Dog, what price would you sell it for? Do you still have the spacers that came with the unit.

Some AMC20 , Dana 44 , and Chrysler 8-3/4 applications require the use of an axle spacer, which is included with these units.

 

[Old Dog]

Hi Old Dog, what price would you sell it for? Do you still have the spacers that came with the unit.

Some AMC20 , Dana 44 , and Chrysler 8-3/4 applications require the use of an axle spacer, which is included with these units.

I'd like to get 250 for it.
I might have the spacer, I'm not sure, as you don't use it with 1 piece axles.

 

[Canadian CJ 7]

I'd like to get 250 for it.
I might have the spacer, I'm not sure, as you don't use it with 1 piece axles.

Thanks Old Dog, I am going to replace the axles this summer, then do the gear swap next year when I can afford it. Makes sense to do it all at once, but I have spend a few grand this year on the jeep to get it road worthy again. The hard work has paid off and I am enjoying the summer weather with the top down, just like I did 20 years ago with my first CJ