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Re: Axle tramp

Posted: Mon Sep 16, 2019 12:30 pm
by ndevans
jaekl wrote: Mon Sep 16, 2019 11:48 am Bear in mid that the restraint of the bearing is designed such that a seize bearing will spin in the hub rather than the axle housing. The nut needs to clamp much tighter than the halfshaft flange against the out race. The outer race has better leverage so its clamping should be rather light. It's cheaper, easier to replace the hub than the axle housing. What's the argument for the criticality of the flange gasket?
You raise a good point about the bearing nut. I don't think there is a torque specified for it, and as I haven't got a suitable socket, I have used a large spanner in the past. Maybe I am not quite getting enough clamping force from the nut?

Re: Axle tramp

Posted: Mon Sep 16, 2019 2:20 pm
by philthehill
There is no specified torque for the Minor axle hub bearing nut. It should be done up tight but do not use gorilla strength on the nut./spanner.

If you use a socket make sure that you grind out the concave from the centre of the socket. The hub nut is not that thick and you do need all the grip on the nut you can get.
Or alternatively use a flat plate spanner.

https://www.bullmotifspares.co.uk/produ ... 105/DIF105

https://www.ebay.co.uk/itm/rear-hub-nut ... xyuOtRa9uD

Re: Axle tramp

Posted: Mon Sep 16, 2019 7:28 pm
by ampwhu
I've used a 47mm socket for about 20 years. It works fine

Re: Axle tramp

Posted: Mon Sep 16, 2019 8:12 pm
by philthehill
At least you did not use a cold chisel to undo and tighten the nut.
I have found many a Minor rear hub nut butchered that way. :(

Re: Axle tramp

Posted: Mon Sep 16, 2019 8:35 pm
by myoldjalopy
Not to mention the steering wheel nut :(

Re: Axle tramp

Posted: Mon Sep 16, 2019 10:10 pm
by pgp001
It's probably worth mentioning that one side is right hand and the other side is left hand threaded as well.
Not immediately obvious if you don't know about it.

Phil

Re: Axle tramp

Posted: Mon Sep 16, 2019 11:49 pm
by ndevans
philthehill wrote: Mon Sep 16, 2019 8:12 pm At least you did not use a cold chisel to undo and tighten the nut.
I have found many a Minor rear hub nut butchered that way. :(
Ah....errr......
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Re: Axle tramp

Posted: Mon Sep 16, 2019 11:56 pm
by ndevans
There is clear evidence that the bearing has been turning in the hub-the outer edge is polished, and the hub inner face is as well, but not as much. It's also swimming in oil, but I think that's where it spilled out when I removed the halfshaft.
The bearing nut and tab washer were done up. I was able to push the bearing out of the hub, with some difficulty, with my hands. I can't push it back in with my fingers, it would require pressing.
I have a new bearing and seal kit, and I will get some bearing lock as well. Loctite 641 is apparently suitable for items that need periodic dismantling.
Looking at the price of hub spanners, I think I will make one from some scrap angle iron.

Re: Axle tramp

Posted: Tue Sep 17, 2019 12:02 am
by ndevans
Here is the splined end of one of the halfshafts. Both sides are pretty much the same. There is a small amount of wear, not easily visible in the photo.
Both halfshafts are hardened, were fitted in 1995, and have done around 50,000 miles.
Do they look good for more service?

Cheers N
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Re: Axle tramp

Posted: Tue Sep 17, 2019 7:26 am
by philthehill
I have seen worse.

If there had been any sign of twisting of the splines I would have said replace but looking closely at the photo I would suggest that there is plenty of life left in those half shafts yet.

Refit and enjoy.

Re the hub nut photo above - the problem with using a chisel to undo and do up, especially the doing up is how do you know how tight the nut is ? - only using a spanner/socket with lever can you judge the tightness.

To do the job properly a spanner or socket must be used.

Phil

Re: Axle tramp

Posted: Wed Sep 18, 2019 5:48 pm
by ndevans
Have had a further look at my 3.9:1 diff now, the cage is separated from the case, but still assembled, leaving just the main pinion, bearing & flange mounted in the case.

Both cage bearings look and feel ok. They spin smoothly & quietly, and there is only just detectable lateral movement between inner & outer race. I'm thinking that they are fit for further use.

The cage pinions look a little worn, and one seems to have some lateral play on its shaft. I believe these are easily replaced, and I am thinking it would be wise to do so, along with the cage pinion thrust washers. The crown wheel looks good, with little wear.

The main pinion spins, but not particularly freely. I haven't measured it using my home made device, but there is definite resistance to movement when trying to turn it from the flange. It also does not turn as smoothly as the cage bearings. I can't really see the pinion bearing very well, but it does not look worn, and there is oil in there. The pinion itself again looks good with little wear. As a minimum, I am going to replace the pinion oil seal.

I have read the BMC manual on setting up the crown wheel & pinion. If I understand it correctly, there are two parts to it-setting the height of the main pinion relative to the base of the cage bearing seats, and setting the lateral offset of the crown wheel & cage relative to the main pinion c/l.

I know I've asked a similar question before, but just for the sake of clarity-if I just replace the main pinion oil seal, bearing & crush washer (if fitted), and do not change the crown wheel/cage/bearings in any way, apart from replacing the worn cage pinion & thrust washer, can I get away with just resetting the main pinion height?

In other words, if the crown wheel/cage/bearings have not been changed, do I need to reset the crown wheel & cage offset relative to the pinion c/l?

I don't have BMC tool 18G191, and I suspect no one does now, but I do have a DTI.

Cheers, N

Re: Axle tramp

Posted: Wed Sep 18, 2019 6:01 pm
by philthehill
If you change the pinion bearings you may in all probability find that the fore and aft position of the pinion teeth relative to the crown wheel teeth has changes and the meshing then is all up the spout.
If when turning the pinion as is currently and no roughness is felt I would leave well alone.
The pinion shaft is not meant to spin freely because of the preload.
If the crown wheel has not been moved either way in the housing you do not have to reset the crown wheel relative to the pinion but if you replace the pinion bearings I would expect to find the pinion to crown wheel meshing is all up the spout.

Re: Axle tramp

Posted: Thu Sep 19, 2019 12:23 am
by ndevans
Hmm. I would say there is resistance to start the pinion turning, then it turns quite easily. The rollers in the pinion bearing all appear to turn smoothly, and there's little noise. It's not what I'd describe as rough, but not as smooth as the two cage pinions. As far as I can judge, there is no axial movement in the line of the pinion shaft.

Re: Axle tramp

Posted: Thu Sep 19, 2019 11:09 am
by pgp001
I'm still on the edge of my seat wanting to know where all that free play in your prop shaft was coming from.
Did you ever find out for sure what that was ?

Phil

Re: Axle tramp

Posted: Thu Sep 19, 2019 11:48 am
by ndevans
Don't know, I haven't actually got the 4.22:1 diff off the axle yet, and I may not for a while, depending on how quick I am at getting the 3.9:1 back together.
The half shaft splines look ok. Could it be the loose bearing in the hub that caused the play?

Re: Axle tramp

Posted: Thu Sep 19, 2019 3:29 pm
by pgp001
I have my doubts that your hub bearings have got anything to do with the play, after all they rotate by design, but yours were moving axially in the hubs, and that would not account for any rotational clearance. I think you have another undiscovered problem lurking in that diff. :(

Please keep us informed when you do get it in bits, it is interesting to hear the outcome of these problems.

Phil

Re: Axle tramp

Posted: Fri Sep 20, 2019 12:18 am
by ndevans
I'll report my findings either on here, and/or my differential overhaul thread. All these things may be useful to someone in future.

Re: Axle tramp

Posted: Fri Sep 20, 2019 10:19 pm
by ndevans
Picking up new lh hub nut tomorrow, and a few other bits and bobs, from Charlie Ware's, then going to pressure clean the axle casing, reassemble the bearings in the hubs with bearing lock, then have the 4:22:1 diff off for a gander. I'll decide then whether I put it back on and keep the car on the road while I finish the 3.9:1, or just crack on with the 3.9.

Re: Axle tramp

Posted: Sat Sep 21, 2019 10:51 pm
by ndevans
Rear axle stripped and pressure washed. Diff removed. A cursory look suggests nothing major wrong with it, but it's covered in oil still, so not easy to tell.
In other news, home made hub spanner worked well

Re: Axle tramp

Posted: Sun Sep 22, 2019 8:29 am
by RobThomas
I fitted several extra clamps to the front half of the nasty Bull Motif rear springs and the tramp has completely gone. Still worked out cheaper than buying proper springs from Rossendale.