Morris Minor Owners Club

And here is the new, improved, extra brilliant white work surface and vice setup. Not much to see actually, but underneath I have reinforced the surface with 50x50mm timber, screwed to the wall in about 15 places. It's much stronger and more rigid now, and barely moves even with 120ftlb on the torque wrench.
It'll probably be Weds before I can finish torqueing the flange nut properly, but it's all progress.

Last night I managed to get the flange nut up to 140ftlb. The bench held firm, which is pleasing, but the pinion bearing pre-load is still not significantly higher-it's around 1/4 of what it should be. I've tried two different torque wrenches, so I'm fairly sure it's not a wrench calibration issue.
So do I need to strip it completely, and renew the crush spacer? What if there isn't a crush spacer?
I haven't so far tried using engineers blue to see the pinion/crown wheel mating area.

Cheers N

Bad luck.

The spacer will either be a crush spacer or a solid spacer. It is highly unlikely that you will find a 'No Spacer' situation.

If you are able to remove the outer bearing centre race you can access the spacer without removing the pinion shaft from the casing.
When the pinion bearing is stripped out and you find it is a crush spacer replace the crush spacer with another crush spacer. If it is a solid spacer adjust the shimming or replace with a crush spacer. With the solid spacer the preload is adjusted by adding or subtracting shims from between the spacer and outer/front bearing..

If the spacer is solid and the pinion bearing races are worn the solid spacer/shims will keep the bearings apart and you will be unable to reach the required pre-load.

Declan, did you get an answer from ESM re the cwp being A or BTA?

Also, can anyone shed any light on this?

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?

If they are indeed those measurements there must be a solid spacer to make up the difference.

I haven’t seen one listed anywhere, have you?

PG,
Not until now although I sent them a reminder.
Regards
Declan

Ok, thanks Phil & Declan.

Since it looks like I am committed now to getting the pinion bearing off, I guess I might as well replace it. Do I need a bearing puller to remove the outer bearing inner race? Also, will I be able to remove the new oil seal that I fitted a couple of weeks ago, without damaging it?

If I don't replace the outer bearing, just the crush spacer or solid spacer & shims, I guess I have to go through the procedure for setting the pinion height?

Should I take measurements of the current height of the pinion face wrt the cage bearing seats, or wrt anything else?

Cheers N

Declan_Burns wrote: ↑Wed Oct 30, 2019 10:34 am PG,
Not until now although I sent them a reminder.
Regards
Declan

Thanks Declan, any ideas on the spacer sizes?

PG,
I measured the crush spacer at 18.95 … 18.98mm on my 3.9 diff. The new one I put in measured 20.28mm. I had solid spacers made and still have quite a few of them if anybody needs them. They are 20.04/20.05mm. I intend to use one when I take the diff out. They will have to be ground to finish size which can be measured with a dial gauge.
Regards
Declan

That’s very odd then, the crush spacers are the same. Anyone taken out a solid one and measured it?

If/when I get that far, I'll let you know!

PG,
I have never seen a Moggy differential with a solid spacer. That is why I had the solid spacers made the same size as the new crush washer.
Regards
Declan

The BMC part number for the solid spacer is ATA7046.

You should be able to remove the centre race of the outer bearing and gain access to the spacer solid or crush which can then be removed and replaced.

Looking back through this thread there is a picture of the pinion fitted with the outer bearing centre race removed - so access to the spacer is possible. Therefore I would suggest that there is no need to strip out the outer bearing completely. It all depends upon the fit of the outer bearing inner race on the pinion shaft and the fit of the spacer also on the pinion shaft.

As regards the pinion seal - with care and using a large flat screw driver the seal can be removed and refitted again for further use.

Ok thanks Phil. I'm prepared to buy another oil seal if necessary, I'd just like to avoid it.

So does the inner race just tap out?

And, if I have a crush spacer fitted, is it ok to fit a solid spacer and shims instead? I have a new crush spacer, just out of interest would like to know.

Cheers N

philthehill wrote: ↑Wed Oct 30, 2019 4:52 pm The BMC part number for the solid spacer is ATA7046.

And the crush spacer is BTA532, so it could be another difference between the ATA and BTA diffs?

Crush spacer BTA532 can be used for either ATA or BTA diff carriers.

philthehill wrote: ↑Wed Oct 30, 2019 5:19 pm Crush spacer BTA532 can be used for either ATA or BTA diff carriers.

I’d have trouble using it in mine, it’s half the length it needs to be

The whole pinion with the inner bearing cone and spacer just taps out. You won't be disturbing anything by removing it. The outer bearing is nowhere near as tight as the inner. The outer and inner bearing cups remain in place. (You need a drift to remove the cups.) Then you will soon see if you have a crush spacer or not.
Regards
Declan

Here’s the difference.