I have a 71/72 differential with bolt in axles, it has been completely rebuilt with parts supplied by Monzaz. I forgot to give the backing plates to the rebuilder so now I'm having to remove the axles to fit up the backing plates. I've got one axle out (haven't touched the other one yet) and find I can't get the bearing or race seated back in the axle tube. The seal is still completely exposed.

The service manual says to "drive the axle home" during re-installation...the axle is as far into the differential as it can go so I'm at a loss as to how to get the race and seal fully seated. What's the secret?

 

A block of wood and a hammer.

 

I'm guessing that you don't have the splines of the axle shaft engaged in the side gear of the differential. Usually you have to ensure that the inboard end of the shaft is forced upward (which is a little difficult given the short amount of axle shaft and flange outside the tube) and rotate slowly until the splines engage. Gravity makes the inboard end want to droop and thus not slide into the side gear.

 

Is the retainer on the correct side of the bearing? Seems to me that it should be fully outboard of the bearing. Perhaps others could weigh in.

 

Are you sure you took out the OLD tapered race? ? I agree with Joe...Maybe the spline is not engaged correctly?
Also did you get those axles from US? The axle behind the retaining plate looks very large in diameter? What is that?

Normally you should be able to get the nuts all started and you can pull each nut in 1/4" at a time cris cross from each other until fully sealed .
We have seen early oiled bearings use the 2146 seal .370 seal and when a 712146 seal .470 - .490 it will not seal all the way....BUT like you said this is not even in the tube end at all?? Jim

 

Yes, I got the axles, bearings, posi...everything from you last year. The axles are Moser 30 spline. I had a professional do the assembly, and the other axle is where it needs to be (still has to come out to add the backing plate for that side). I'll have a look for the old race but will be surprised if he left it in. I can start one or two nuts but definitely not all of them.

I pulled the diff cover off last night and the axle end is well into the carrier - I can grab photos this afternoon, but the splines certainly seem to be engaged and sliding in.

As for hitting a block of wood, are you suggesting that be done on the end of the axle? Because I don't see how that would work - the axle seems to be coming to a hard metal on metal stop and there's nothing to apply driving pressure against the race.

I'm definitely getting the impression this should be going in a lot easier than it is, though.

 

I'll have a look for the old race but will be surprised if he left it in.


Note: this is very easy to overlook....

 

Maybe one / some of the friction discs in the carrier are out of alignment? If so, try rotating the shaft back and forth while pressing inwards to get them to align.

 

Just can't catch a brake. Or a break.

I pulled the axle again, checked that the old race hadn't been left in (it wasn't) and tried get it in place without the backing plate in my way. it seemed to get to where it needed to be eventually - I had to use a hammer/block and center the assembly so the inner race (or whatever that bit on the inside end of the bearing is) so it would slide into it's bore. Feeling more confident, I pulled it, realized I had the wrong backing plate and figured the Universe had been sending me a message. Got the correct backing plate for the side, slid the axle back...and things did seem to be a lot better...I was able to thread then tighten the nuts on the cover plate (with a wrench)...which is now warped. The axle had excessive play both up/down and in/out so obviously something is still not right there.









And now...of course...I can't get the flipping axle back out! :-( I've got a brake drum reversed and trying the slide hammer method but so far no luck.

Before getting too frustrated on that side, I thought I'd give the opposite axle a shot. Got it out easily...installed the gasket and backing plate...slid the axle back in...tightened everything down and it actually seems to be "right". That's a bit of a confidence builder at least. Bearing is tapered bearing, outer race and seal...this is the "good" side, the "bad" side is the same except the race and seal separate a bit easier. Might need some more grease...if I can get the damned thing out.




Now I need to get the uncooperative side back out.

 

Alright...20th time is the charm? Got the uncooperative axle back out, didn't see any signs of damage to anything so slid it back in and...success!!? Maybe I was finally holding my tongue right, or something.

So the last question at this point is how much end play is acceptable on the axle? The side that behaved is just under 1/16th of an inch and the uncooperative one is just under 1/8th of an inch.

 

There shouldn’t be any end play as you are using a tapered bearing that requires a pre-load. Where as the original axle bearing was a ball bearing.

 

That's what I was afraid of. I haven't torqued the bolts yet, so I guess there's a chance that will take up the slack but with the backing plates already feeling firmly sandwiched I can't see things tightening up all that much.

What's the suggested fix? I didn't do any of the assembly so I'm not sure if there's a margin of error in pressing the bearing on too far/not enough?

 

The bearing presses on until it can’t go any further, as in no gap between the race and the wider part of the axle (I dunno the technical term).


I pull axle shafts using a short chain and the removed wheel/tire, which has much more mass than a drum. Takes just one bump to pull the shaft.

 

Torqued the plates down to 40 ft/lbs and the axles still have end play (in and out). One side is just under 1/16, the other just over.







Are the cover plates in the right way?

 

Could it be something as simple as the paper gaskets I used behind the backing plates???

 

I noticed from the picture ...I am pretty sure that axle bearing is on backwards. The race should go to the inside of the tube not to the retaining plate. I am not sure if this is causing the issue BUT if this is a tapered bearing...I do not think you have the bearing facing the correct direction when it was pressed. ?? Jim

 

here is the way the bearing should go.

 

Here's the "exploded" view. All the movement I'm experiencing is in the bearing and I think reversing it will remove the play.




Can the bearing be removed and flipped or will I need new bearings?

 

Bingo! A picture is worth the many futile attempts. good luck

 

Welp...got the bearings reversed and rinstalled the axles...there's still a bit of end play but not as much as before. If I'm reading this right, one is at .026" and the other at .008".

 

glad to see you got it sorted out. i can drop off my axle puller if your gonna keep messing around in there