Morris Minor Owners Club

Whilst the dust cap is a separate piece to the pinion flange it should be a tight fit on the pinion flange and should once fitted not rotate or move.

Measure the shims when you remove the carrier and take note of which side they were on. I can only upload five photos at a time so here are the photos of the carrier disassembly.
Regards
Declan

...and the pinion. Make sure you have a decent puller as it is usually very tight interference fit. I did post all these photos before but they seem to have vanished.
Regards
Declan

Thanks Declan. Does your bearing puller grip the outer bearing race, or the inner? Does it leave the bearing re-useable?

Having got the diff cage out of the case, I can see the pinion spins freely and smoothly in its bearing, with little noise, so I'm going to leave the pinion alone, just replace the oil seal. Any idea how I can remove the oil seal, which seems to be firmly rusted in there!

I'm also going to leave the diff bearings alone, for the same reason-they spin freely and smoothly, with no noise.

One of the planet gears in the cage has a fair bit of free play along its shaft-should this be the case, or should I renew the thrust washers? Apart from that, all seems ok, no sign of unusual wear on crown wheel, pinion or sun & planet wheels themselves.

N,
When you try to remove the carrier bearings you will probably find that the bearing separates and the balls go flying all over the workshop. It is an angular contact bearing so if you do try pulling it, do so in a plastic bag. The inner race can then be pulled off separately. Only then have you access to the shims. That is what makes life difficult on re-assembly. To set-up the differential, if for example you are changing the CWP, you need to remove these bearings several times to find the correct shim size. For this reason I made up a set of set-up bearings by grinding down a set of old bearings with a flap wheel so they can slide on and off without the need for a puller. Another alternative is to possibly put the shims on the outside of the bearings. Using the set-up bearings and a dial gauge you can slide the carrier back and forth with a screw driver to measure the shimming required.
If your bearings are OK then leave everything alone. If the trust washers are worn you can replace them.
To remove the oil seal with the pinion in place, you may have to puncture it to get a screw driver in to carefully lever it out. Maybe somebody else has a better suggestion on that.
Regards
Declan

Clean off all the muck around the seal. Soak with penetrating oil. Put a suitable self tapping screw into the metal part of the seal through a length of flat bar. Use the end of the pinion as a fulcrum point and pull up on the flat bar the seal should rise in the case and eventually come out.

Excellent idea Phil!
Regards
Declan

Thanks for the advice chaps.

In fact, after a bit of gentle persuasion with a knife and two screwdrivers, I managed to prise the oil seal out last night. I did think of drilling a hole in it, then using a punch to try to turn it, but I didn't want to risk getting metal swarf in the bearing.

Here it is, does this look ok?
Is that gap in the side an oilway, for keeping the bearing lubricated?

If stripping the diff cage doesn't involve removing the bearings, I will look at the planet wheels & shims, and renew if necessary.

Cheers N

N,
You don't have to pull the bearings to strip the diff cage. Start by driving out the pin. If my memory serves me correctly it is approx. 4mm. Location as in my fifth photo above.
Regards
Declan

Silly question. Why is the crushable spacer apprx 21mm long and the solid spacer is 40.5mm?

PoolGuy wrote: ↑Thu Sep 26, 2019 7:16 pm Silly question. Why is the crushable spacer apprx 21mm long and the solid spacer is 40.5mm?

Good question, can't answer that. My spare crush washer is 21mm as well.

Ok, here is my dissembled diff cage.
Yeah, the oil seal got a bit mangled!
If you look closely, you can see that the pinion on this side of the cage has worn the cage itself
And here's why. The thrust washer under one of the planet wheels was almost non-existent, just a thin ring of metal (bronze?).

The planet wheels themselves look ok, as do the sun wheels, there is a little wear, but I don't think it justifies replacing them. There is wear on the pinion shaft, I will replace this.
Oversize thrust washers are available from ESM, so I'm going to get two normal and one oversize, and see what combination fits best.

Question-the BMC manual talks about peening over the entry hole that the pinion shaft peg goes in. How do I do this? Will some thread lock or bearing lock retain the pin just as well?

Cheers N

While I've got the back axle off the car and in bits, I've taken the opportunity to do a bit of freshening up. Here are the rear brake backplates cleaned, painted & reassembled, ready for fitting to the also cleaned & painted back axle.

Hi nevans

Nice work there.

I want to thank you for taking the time to give us a pictorial coverage of your diff rebuild. Good quality pictures too.

I admit that a lot of the detail is going over my head, but I intend to attempt a diff rebuild soon. I hope that once I am hands-on it will all gel.

Don

Thanks. I've never done a diff before either, so it's a steep learning curve for me. I'll be doing some more on the diff itself next week.

don58van wrote: ↑Thu Oct 03, 2019 7:11 am Hi nevans

Nice work there.

I want to thank you for taking the time to give us a pictorial coverage of your diff rebuild. Good quality pictures too.

I admit that a lot of the detail is going over my head, but I intend to attempt a diff rebuild soon. I hope that once I am hands-on it will all gel.

Don

Ditto, I’m just at the ripping it apart stage. Thanks for sharing.

A few photos this evening of the innards of the diff cage.
The wear in the diff cage where the thrust washer has worn away to a ring is clearly visible. Can I have this machined out, and fit an oversize thrust washer? I have an 0.054" one available, as well as 2 x 0.035" thrust washers.

You could get it machined out but finding someone with the correct tooling will be the problem.

I agree with Phil, personally I would look into replacing it rather than attempting to repair it.
Regards
Declan

It should be noted that the ATA and BTA diff carriers are not interchangeable. The damaged diff carrier in the photo above is a BTA diff carrier.

So basically if you cannot find a machinist to do the job you are unfortunately back to square one.

Ok thanks gents.

So, if I just fit new 0.035" thrust washers, will it be ok?
What if I was to try to turn down a thrust washer so that it fits in the recess that's been worn? Could that work?