Model 20 Axle Shaft Wear?

Pulled the driver's side rear axle shaft on the '79 CJ7 I'm working on to fix a leaky seal, and found some strange wear on the end of the shaft. It appears to have some kind of locker in it - there's a Detroit sticker in the glove box and with one wheel on the ground and the trans. in neutral, while spinning the other wheel the driveshaft doesn't move.

Wheel bearing mounted too far out? I'm going to replace the bearing with the seals. Is this wear any cause for concern? I'd guess it's .025"-.040" deep, depending on how much taper the end of the shaft once had that I can't see now.

 

is this a tapered axle? looks like an aftermarket flanged kit and there wasn't enough end play and it wore on the thrust block.

 

Nope, flanged. After a brief skimming of info it appears it has been converted to flanged semi-floating axle shafts, with a grease fitting in the retainer. Apparently not all these kits are created equal? The Jeeps pushing 33's through a 304/T18, so I need to fix it right whatever I do.

 

What Sterlclan said. Not enough endplay causing excessive wear. That shaft needs replaced. I'd also pull the cover and take a look. the metal from the end of the shaft went somewhere...
I'd also take a close look at the other shaft.

 

I would also take a good look at everything. It is possible the axle shaft could be serviceable you might be able to clean out some sparkles re shim seals and go?

 

It's a model 20 axle. Run it till it drops and replace it for $50. If you were looking to spend money, replace it with an intermediate Dana 44.

 

Well, the Jeep was left with me with instructions to do whatever it needed so that it'd be reliable, so "running it 'til it drops" isn't an option. What year range axle am I looking for, '76-82?

 

I haven't driven it (just got it running last night) but the pinion seal is leaking, too, so I'll wind up looking inside and assessing the cost of fixing the model 20 vs. finding a D44.

 

I have the Mosier one piece axles in a model 20. they have a spacer ring that has to be ground down so when test fit with the bearing that will be pressed on the axle is sticking out .02 - .08.
I don't know what axle you have, but this procedure should apply to any axle used on a model 20, if the spacer was not used or ground too far the axle could push in and grind as shown.
http://www.moserengineering.com/moser/wp-content/uploads/2010/04/JeepInstructions.pdf
Jay

 

Pulled the cover off for inspection today. No big chunks of metal or horrible damage, but I'm not sure these wear patterns are quite right:
Drive:


Coast:


Pinion:


The contact area of the pinion teeth isn't banged up, but has consistent fine scratches running the length of the teeth - not polished like (I think) it should be. The fluid was a nice gear oil green color and didn't seem to have a lot of miles or excessive age on it, but there's a good deposit of metallic goop left in the bottom after draining. What say ya'll?

 

I'd run a pattern check using gear marking compound or prussian blue and get a true indicator of the pattern.

 

Looks like a powerlock?? If so, normal clutch wear makes lots of goop. I put a magnet on the cover or use a magnetic plug on most axles to keep the metal out of the bearings.

 

Ditto, nickmil.

 

Okay, gear heads - whatcha think? To my novice eye it looks passable.
Drive:




Coast:




Pinion: