AMC 20 Rebuild Woes

[arrow115]

Hello! First post. First Jeep.

I bought/rescued a project 1979 CJ7 with the goal of a full frame up restoration.

I am currently stuck on this AMC20 rear axle. I tore it down and replaced all of the seals and bearings. I rebuilt the drum breaks and when I mounted the rear tires, now the drivers side drum is rubbing on the shoes and brake backing plate. I have adjusted the end play with shims according to the service manual but still the drum rubs on the shoes and backing plate. I noticed whoever worked on it last put washers under the drum on the drivers side. I guess they were having same issue.

I am wondering if the hub or axle shaft is bent.

I am using the factory two piece axles. I am really considering the one piece axle conversion, but I was hoping to get this issue figured out before I spend more money.

Any help or advice would be very appreciated!

 

[gert]

Hello! First post. First Jeep.



I bought/rescued a project 1979 CJ7 with the goal of a full frame up restoration.



I am currently stuck on this AMC20 rear axle. I tore it down and replaced all of the seals and bearings. I rebuilt the drum breaks and when I mounted the rear tires, now the drivers side drum is rubbing on the shoes and brake backing plate. I have adjusted the end play with shims according to the service manual but still the drum rubs on the shoes and backing plate. I noticed whoever worked on it last put washers under the drum on the drivers side. I guess they were having same issue.



I am wondering if the hub or axle shaft is bent.



I am using the factory two piece axles. I am really considering the one piece axle conversion, but I was hoping to get this issue figured out before I spend more money.



Any help or advice would be very appreciated!

Sounds like the hub is pressed on the axle to far and now the drum is rubbing, I highly recommend the 1 piece axles it's just a matter of time before the hub spins on your axle shaft, Welcome aboard from Texas stay around and share your adventure with us we love Jeep porn and have a build section that you can document your progress in


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[jakeh937]

I am too thinking about one piece axles. And welcome! Wish I could input some info but I have never torn into mine yet. Luckily, many people have wonderful knowledge and experience! [emoji6]


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[arrow115]

Sounds like the hub is pressed on the axle to far and now the drum is rubbing, I highly recommend the 1 piece axles it's just a matter of time before the hub spins on your axle shaft, Welcome aboard from Texas stay around and share your adventure with us we love Jeep porn and have a build section that you can document your progress in


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Thank you for the advice! I have suspected that moving to a one piece axle setup wouldn't be a bad idea. I am seeing a few different brands. Does any one have any recommendations? If I have to spend money, I might as well buy something good that I don't have issues with. I see Crown and Omix, but also G2 and Moser.

Thanks again.

 

[gert]

Thank you for the advice! I have suspected that moving to a one piece axle setup wouldn't be a bad idea. I am seeing a few different brands. Does any one have any recommendations? If I have to spend money, I might as well buy something good that I don't have issues with. I see Crown and Omix, but also G2 and Moser.



Thanks again.

I think Moser is the best, Crown and Omix are both cheap Chinese metal not sure where G2 is made but Moser is Made in USA and I am saving my pennies for their axles front and rear


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[Lumpy Grits]

I have seen this issue after a 'spun' axle bearing chew'd up the axle tube.
Moser is the best made 1 piece axle set up. That said-I hate the AMC mod 20 axle for many reasons. Don't put much $$$ into it without looking to upgrade to a 44 or a F/9".
FWIW: I seen the washer deal done like this, more than once.....
LG

 

[arrow115]

I have seen this issue after a 'spun' axle bearing chew'd up the axle tube.
Moser is the best made 1 piece axle set up. That said-I hate the AMC mod 20 axle for many reasons. Don't put much $$$ into it without looking to upgrade to a 44 or a F/9".
FWIW: I seen the washer deal done like this, more than once.....
LG

I was about to pull the trigger on the Moser one piece kit when I saw this. I looked at the tube and didnt see anything obvious. Would a spun axle bearing leave some pretty clear evidence in the tube? The important question is if this axle spun the axle bearing and chewed up the tube, would replacing the axle shafts with a one piece setup resolve the issue? I would like to avoid having to swap axles if I can right now.

Thanks!

 

[gert]

I was about to pull the trigger on the Moser one piece kit when I saw this. I looked at the tube and didnt see anything obvious. Would a spun axle bearing leave some pretty clear evidence in the tube? The important question is if this axle spun the axle bearing and chewed up the tube, would replacing the axle shafts with a one piece setup resolve the issue? I would like to avoid having to swap axles if I can right now.



Thanks!

If the bearing spun and chewed up the axle the housing end it would be pretty scared up, it should be obvious that metal has been ground out of the housing end.
Does your bearing fit in the end of the housing good? Any excess slop? Does the driver side appear to deeper in the housing than the passenger bearing?

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[arrow115]

If the bearing spun and chewed up the axle the housing end it would be pretty scared up, it should be obvious that metal has been ground out of the housing end.
Does your bearing fit in the end of the housing good? Any excess slop? Does the driver side appear to deeper in the housing than the passenger bearing?

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It doesn't appear scarred up and the bearing fits snugly in there. I figured it would be obvious, just trying to make sure I dont have some other underlying issue before I throw down the money for the Moser set.

 

[gert]

It doesn't appear scarred up and the bearing fits snugly in there. I figured it would be obvious, just trying to make sure I dont have some other underlying issue before I throw down the money for the Moser set.

No worries that's good thinking on your part


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[Lumpy Grits]

The scars inside the tube would be noticeable, IF you looked for them.
I would go with Moser, as the 2 piece axles on the market today are China made JUNK.
LG

 

[Belizean]

I did the Moser about 20 years ago at least and have no regrets

 

[gert]

I did the Moser about 20 years ago at least and have no regrets

Wow now there's a good review


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[arrow115]

I did the Moser about 20 years ago at least and have no regrets

Doesn't any better than that! I am sold. Ordered.

I am going with the Moser axle for sure now, but I looked everything over because I have been curious to what the problem was exactly. I found a couple of things that make the decision to pull the trigger on the Moser one piece axle kit a no brainer.

First, when I was looking at the groves on the back of the hub where it slides on to the axle splines, I noticed that it looked the hub had been rammed on or over tightened. I could see where groves had been made beyond the factory groves on the hub. My guess is someone got trigger happy with an impact. Who knows.

Second issue which pretty much junks the two piece setup anyways is the groves on the hub are very well worn. It looks like it would fail pretty quick once I started driving my cj.

Thanks again for the advice! I will update once the new one piece axles are installed.

 

[Lumpy Grits]

I urge you to also order an extra bearing set and seals to keep on hand.
LG

 

[arrow115]

I urge you to also order an extra bearing set and seals to keep on hand.
LG

Sounds like good advice! Will do. Thank you.

 

[Lumpy Grits]

Good luck with this.
Please keep us updated with the install.

LG

 

[gert]

Sweet we need pics or it didn't happen lol


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[Belizean]

I urge you to also order an extra bearing set and seals to keep on hand.
LG

This is a good idea. My replacement seals & bearings have been sitting in a drawer for close to a couple of years. Kinda thinking maybe a different R&P upgrade but just have not pulled my itchy trigger finger on that. The right side has a slight leak.