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bdatkins 08-23-2013 09:09 AM

HELP AMC 20 outer bearing slop
2 Attachment(s)
1978 CJ5. Spent the last 5 years or so slowly rebuilding her. I'll post a build thread as soon as I actually get her to a stopping point.

A few years back the outer bearing on the passenger's side of my AMC 20 failed. I replaced it and went on about my way. I have noticed a bit of oil leaking from around the hub and pulled the axle back out to check the seals. The seals were fine but the bearing is showing signs of failure. So I had a new bearing pressed on and as I was reassembling everything I noticed the bearing race has a lot of slop around it. After looking at it, it looks like bearing has spun in there at some point worn a grove where the race sits. The slop is considerable.

You can see the grove in the close up.

So I have two questions. Have any of you run into this before and what did you do?

My first thought was to use some shim stock get a tight fit. Then I thought that the right way to do things would be to take it to a machine shop and have them either weld it and rebore it or bore it and bush it. Does anyone know what the ID is supposed to be?

All help and thoughts are appreciated.

82JeepCJ7 08-23-2013 09:59 AM

Looks normal to me. That is not where the bearing runs anyway. I would double check the breather to make sure it's not clogged. Mine was leaking there and after replacing all the seals, it still leaked. I tore it apart again, replaced the seals, and this time blew the breather out. Apparently mud had clogged the breather top. Put it all back together and no leaks.

Are you still running the 2pc axles or have you upgraded to 1pc?

I'm running a Warn Full Float kit, so I don't have those issues. I'm trying to remember back to 1994 when I pulled the 2pc axles out...

baldfatdad 08-23-2013 10:30 AM

Check the OD of the bearing and the ID of the axle. Come back with that info.

LumpyGrits 08-23-2013 10:38 AM

The seals are NOT 'fine'. They both must be replaced.
Measure the ID in the axle housing, and the OD of the bearing race. Post what you learn.
This is also a classic sign of a bent housing.

bdatkins 08-23-2013 12:34 PM

1 Attachment(s)
I am still running the original 2 piece axles. I did go ahead and replace both seals. I've talked to a couple of automotive machine shops and some bearing places. No one seems to make a bearing with the demensions I would need. The consensus seems to be to use some .03 shim stock and maybe some Permatex® Bearing Mount for Worn Parts and see what happens. I will probably end up upgrading to a better axle some time. Here are the deminsions.

LumpyGrits 08-23-2013 02:38 PM

DUMP those POS, 2 piece axles ASAP!! Don't even waste any more time/$$$ on those dang things!!!
Get a set of Moser's.
Loc-tite stud and bearing mount will work well for the egg-shaped axle housing.

turbogus 08-29-2013 08:55 AM

To those whom have read my pasted posts over the last couple years, my apologies. (my little tin drum) It's just that mine were seemingly among the worst of the Corporate 20 hassles;

I purchased my '78 CJ 5 a couple of years ago (January '05) and had been having some rear axle problems. Shortly after acquiring this CJ axle lube was seeping out of the hub. Upon removing the axles we noticed that the inner wheel bearings were WELDED to the one piece axle, not by heat/friction, but by someone with a welder! A local shop re kitted this axle (narrow AMC 20) with a Yukon 1 piece axle kit. 1st try and the bearing free play was too tight - burned up the wheel bearings. 2nd try, too loose - axle backed out of the housing shortly after leaving shop. 3rd try and things went well for about two months and then noticed some seepage at the rear hub again. Sure enough, the free play had increased. This go, a non stock bearing keeper was installed to hold bearing firmly in place -we hoped! The shop chief noticed that there were two half circle ( ) inserts incorporated into this axle (This may have been what had made the marks in your axle tubes) that were part of the 'welded' axle, no mention of these in the AMC service manual that I luckily had acquired since getting this Jeep, and another odd thing is correct free play couldn't be obtained without these half circle inserts. We contacted Randy's Ring and Pinion and learned that a spacer was missing for the kit we had purchased from them earlier. We had to pull the dang thing apart AGAIN and with Randy's on the phone for guidance we set the bearing clearance at the long side of tolerance, 0.62
One week later I smelled that old 'hot bearing' odor I had become so familiar with.

pulled the axles again and saw the damn roller bearings formed a 'conga line'. So I made a trip out to Mac's Jeep Parts and we pulled a Dana 44 out of an old Jeep Scrambler, installed a Lock Right differential and new bearings throughout and I've not had any issues since (knock on wood). After turning in the AMC 20 for core we noticed that the troubles lied in that the axle tubes had become or had always been (from reading other accounts on the web) crooked from the differential~!
I sure hope yours is an easier path!

bdatkins 09-11-2013 08:53 AM

Just an update. I ended up putting some .015 shim stock around the race and using some permeatex bearing mount for worn parts. Got it all put back together. Everything seemed to fit a lot better. Except... I had topped off the gear oil and then actually took a long trip. Well half way there I noticed that the gear oil was coming out around the hubs and bringing all my freshly packed grease with it! I am assuming that my vent is clogged and the pressure from the heat on the long trip caused the oil to push out... Now I get to pull everything back apart to repack my bearings...

bdatkins 09-11-2013 08:56 AM

But thanks everyone for the help

LumpyGrits 09-11-2013 09:25 AM

Have you confirmed that you do NOT have a bent housing?

bdatkins 09-11-2013 09:37 AM

You know, I havent. What is the best way to do that?

LumpyGrits 09-11-2013 09:54 AM

The best way, is to pull and disassemble the axle housing and mount it to a surface plate with a height gauge and or a LASER to check axle tube centerline(C/L) from the carrier bearing 'saddles'.

turbogus 09-11-2013 10:02 AM


Originally Posted by LumpyGrits (Post 15902633)
Have you confirmed that you do NOT have a bent housing?

That's exactly what 'BB's trouble was, but it did not become apparent until we pulled the entire axle out (hub to hub). This may be a common issue on our older CJ's that were rode hard and put away wet over the decades.

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