1930s half shaft.

[Tony Fearn]

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I've had a problem with a half shaft on a 1933 7hp Jowett.
The ball bearing at the hub end of the shaft, which you can see if you remove the hub and the oil retaining cork, has seized.
The outer race is still a press fit in the rear axle.
The bearing doesn't turn because the inner race is static due to the seizure.
The half shaft still turns, and as the inner race is hardened, the latter has worn the half shaft away - see sketch above.
As you can imagine, if the shaft became too thin, when driving along, it could break and the wheel would come off, hub, and brake drum as well.
I've replaced the axle, but would like to dismantle the original one with the worn half shaft.
The instruction book states how to remove a half shaft up to a point, but I was wondering if there's anyone out there that has completely dismantled such a rear axle, and how they went about it.
Should I try to remove the axle tube first before I split the diff casing?
Will the tube come off if there's a burr created by the wear?......etc. etc..
All replies (if there are any) will be gratefully received.
Tony.
P.S. click on picture to enlarge.

[ian Howell]

Tony: -

I have not had to do this to any car half-shaft but I did have a similar problem with a pump shaft when I was at sea (No AA to call in mid Atlantic!).

The bearing is 'shot' so nothing to be gained by retrieving it intact.

Attack the cage containing the balls, remove the remnants of the cage, then shuffle the balls to one side and the shaft to the other side and remove the balls.

Now the shaft with the inner bearing ring still in place (probably won't come over the 'chafing' on the shaft), can be withdrawn from the tube.

The outer ring can now be gripped with a normal bearing puller arranged for internal fitting.

The inner ring can be cut away with an angle grinder (CAREFUL!) and split.

It should be possible to 'metal spray' the shaft damage and re-grind to fit a new bearing. (We had a spare shaft).

Robert's your mother's brother. Perhaps?

[Tony Fearn]

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Thanks Ian for your thoughts.
The pre-war Jowett axle, as you can see from the picture above, is rather a different kettle of fish (but from Idle not the mid-Atlantic).
In 'The Book of the Jowett', as well as the instruction book, there's a half-hearted article on how to change the half shaft, but it misses a few important and salient points for the novice.
It glibly tells us that we have to split the aluminium differential housing, and having done so to tap out the balance gear shaft.
After this, with a bit of jiggling the half shaft should be removable.

I have the rear axle on the bench, and have removed the pinion and its housing, and the seven bolts from around the differential housing, and have managed to part the latter with a mallet so there's about 1/4" gap between the two halves - and it won't move anymore at the moment.
I don't know if the axle tube will part sufficiently for me to access the innards and get to the balance shaft, but it must do according to the book.
Maybe, and I'll address this tomorrow, as you say there could be a substantial burr on the outer part of the worn shaft which precludes the axle tube coming any further apart until the burr's removed.
But I have a feeling that the inner bearing ring of the seized ball race is normally a tight fit on the shaft anyway, and this of course will make it much harder to knock away the axle tube to expose the innards of the differential housing.
This is why I was asking whether anyone has ever changed a shaft, and whether they had to overcome problems.
It sounds to be an easy job from the book, but of course it isn't.
More later perhaps.
I don't have much hair to tear out these days.
Tony.

[Tony Fearn]

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Well, with a bit of luck and a large lump hammer I have split the rear axle.
The offside shaft was the problem, and even after removing the burr, when I pulled the tubes apart, of course it was the nearside that came away easily.
The offside just needed a bit more whoomph, especially on the nut at the axle end, pushing the shaft into the tube, and the whole thing came apart.
So much for the instruction book.
I have attached photos to show what the inside of the diff looks like.
The white dot is on the balance gear shaft which I will attempt to remove in the next few days.
This should allow the half-shafts to come away from the differential as detailed in the instruction booklet.
We shall see!
BUT.. have a look at the photo of the worn shaft end where the bearing had seized.
I suggest you jack-up your pre-war and check there's no play in either half-shaft end within the bearing.

This of course leaves the problem of how to remove the outer wheel bearing from its housing at the hub end of the tube.
I don't have an internal puller and a slide hammer, so I might just try Ian's solution even though I'm not stuck at sea.

Any other suggestions will be most welcome.
Tony.

[Tony Fearn]

Just been on the internet.
Has anyone had experience with such a device as this internal bearing puller?

internal bearing puller.jpg

Tony.

[ian Howell]

Not me Tony!

[Tony Fearn]

Hello again Ian.
I had a brainwave at about 3.30am last night.
I have a lump hammer and a long steel rod, so before going down the road of buying an inside puller, I wondered what brute force would do.
Fortunately I have a couple of joiners' saw benches, so I up-ended the tube half, put the rod into the diff case end, felt my way to the bearing at the hub end and thumped the rod at 3, 6, 9 and twelve o'clock a couple of times and the bearing fell out.

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Now all that I have to do is source new bearings and hopefully, half-shafts.
I'm rather surprised that you are the only one to reply.
Perhaps, as a novice, I didn't know that everyone else has done this before.
I just didn't know where to look for the information.
Regards,
Tony.

[AlanBartlett]

Well done Tony!

I've been lurking/following with interest. Back axles & differentials have always seemed a dark art! As for the puller you mentioned I've used a similar tool for removing spigot bearings from crankshafts. Its surprising how much pull those little legs have.

Good luck on the re assembly.

Alan

[BarryCambs]

Hi Tony

I was lurking as well. I have bearing pullers and slide hammers, so didn't have any clever ideas. It's very interesting though as I have to do my own axle at some stage, which has a huge amount of back lash. I also need the hub taper metal sprayed, as while I managed to get it tight last time, I don't think I will again!

At the moment it has felt seals you kindly sent me a few years ago, but I was thinking of replacing the bearings with modern sealed ones when I rebuild. I do need to check that there's a way for the axle to breath though, as I suspect it's just the felt seals that allow air in and out at the moment.

[Tony Fearn]

Hello Alan and Barry, and thanks for the input.
It's good to see that Ian and I are not the only ones interested in 'the dark arts', although I don't think we ever lurk......?
I had cause to send the rear axle from 'Mary Ellen' away to be sorted in 2009 when the same thing had happened.
At that time I had a NOS half shaft that I bought from Roy Braddock around 30 years previously, along with a NOS bearing, just in case.
Cavendish garage in Keighley did the job expertly.

Fast forward to the Tewksbury Rally in 2016, when I bought another NOS half-shaft from Bob Holmes at a very reasonable price, just in case.
Again, foresight is a useful thing, so I have the un-used half-shaft for 'Sarah Jane', but not the bearings this time.

I rang Mike Kav to ask his advice on the bearings, and as I write, tomorrow I'm posting the very rough bearing to him, and he will try to sort me out via his Bearing Factor.
I will replace both bearings whilst the axle is disassembled.

The larger bearings on either side of the differential case seem to be OK, presumably as they are constantly oiled in the diff housing.

It's quite a coincidence that the bearings which seized in both cars were on the off-side - any ideas for future reference?

Barry, I hadn't thought of back axle breathing, but two of the spare rear axles I have, had cork seals rather than the felt ones we have been using.
They were a tight fit in the bearing housing just before the hub. Perhaps they were original and so were used only to keep the grease from the brakes.
Maybe if you go along the route of metal-spraying and re-grinding your half-shafts, we could all (or at least four of us) hear about it on the Forum.

Regards to all,

Tony.

[ian Howell]

Tony et al: -

Blinding glimpse of the obvious - if you can't pull it - push it!

I continue to watch with interest - and not a little trepidation!

There is a lot of 'lash' in my Long Four's back axle, which I have so far put down to wear in the diff 'planet' bearings, or the idler shaft. Now I wonder....

With regard to the oil seals, in my 1948 Bradford (back in the 1960's) the seals were sort of coils of cork with the 'thread' arranged to 'screw' any oil back into the casing (except of course in reverse).

I assume the bearing - RMS 9 - has 1 1/8" bore. Should not be too difficult to source but prices vary widely between 'Chinese' versions and NOS RHP or Fafnir items.

I am watching this space . . . .

[Tony Fearn]

I've spent a good few hours in the garage trying to get the rear axle ready to be re-assembled for when I receive the new wheel bearings.
I've tried the new half-shaft a number of times but have found that the splined diff end is a little longer than the one I took off, or the two I have which need fettling. This end bears on the balance gear shaft. I couldn't get the balance gear shaft to go back in.
Anyway, I've ground the end of the half-shaft bit by bit, (not very expertly) and tried a few times to fit it and I think I'm nearly there.
It was 6.45 pm and I was hungry, so there's always tomorrow.
I hope to write again about the problems, such as the balance gears falling out onto the floor when I removed the gear shaft, but to whet your appetite, here's a photo of the diff end of the half-shaft with the split collars.

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Tony.

[Tony Fearn]

Hello again.
I remembered that some time ago I posted this sketch of one way of removing a rear axle bearing if you didn't want to split the diff. casing.
You'll need quite a bit of kit, but as we're talking rear axles, I thought it might be a good idea to include it once more in this post.

Rear axle bearing removal.jpg

By the way the half-shaft has been replaced and the diff seems to work.
I've made a few notes which I need to sort, and although I don't wish to seem to be teaching my grandma to suck eggs, I hope to post them later.
They might be a bit boring to read through, but every little bit of information may help someone else.
Tony.

[Forumadmin]

Tony,
There are a number of grandmas who read JT.

[ian Howell]

You can never have too much information for a job that is seldom done.

Bob Jones' notes should by now be up to volume (5?)!