Axle tramp

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philthehill
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Re: Axle tramp

Post by philthehill »

Rob
I can second that.
A neat trick I learnt from the American Hot Rod magazines in the 60s/70s was to put additional clamps on the front half of the spring and if self locking nuts were used the tension of the bolts could be adjusted to not only eliminate tramp but adjust the spring ride.
Just fitting the clamps to my standard Minor 5 leaf springs made such a difference to the ride and handling.
Phil

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ndevans
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Re: Axle tramp

Post by ndevans »

Mine aren't from BM, they were new last year. The old ones were, and the spring clamps had completely rusted away. I did get a set of new clamps from ESM, but never fitted them, I decided that they sagged too much, and replaced them.

Edit re the above post-my new springs have two clamps fore and aft of the centre-is it worth adding another?
Last edited by ndevans on Sun Sep 22, 2019 10:01 am, edited 2 times in total.
cheers N

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33063, Eridge, Sept 2021 by Neil Evans, on Flickr
'69 Traveller, 1275, discs.
philthehill
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Re: Axle tramp

Post by philthehill »

If the spring leaf is not held by a clamp it is a good idea to fit one.
The two shorter leaves do not need the clamp.

Les posted a thread on improved spring clamps - if you can find it you will find it worthwhile copying his ideas.

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ndevans
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Re: Axle tramp

Post by ndevans »

Back axle stripped and cleaned, ready for a coat of paint, which is now drying.
IMG_20190922_164352~2.jpg
IMG_20190922_164352~2.jpg (1.84 MiB) Viewed 4660 times
IMG_20190922_164406~2.jpg
IMG_20190922_164406~2.jpg (1.55 MiB) Viewed 4660 times
I hadn't realised that the diff ratio and approx. date of manufacture are stamped into the axle casing.
IMG_20190922_164329~2.jpg
IMG_20190922_164329~2.jpg (1.26 MiB) Viewed 4660 times
Is it ok to clean the 4.22:1 diff by swilling a bit of white spirit around in it to rinse the oil off?

Cheers N
cheers N

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33063, Eridge, Sept 2021 by Neil Evans, on Flickr
'69 Traveller, 1275, discs.
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ndevans
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Re: Axle tramp

Post by ndevans »

Re-fitting the bearings to the hubs today, using a bit of bearing lock.
BMC manual says the outer face of the bearing should not protrude beyond the face of the hub and paper gasket when pressed into position.
However, having measured the hub recess to the shoulder that the bearing sits on, the depth is 16.5mm. Both old bearings, and the unused spare, are almost spot on 17mm.
The gasket I have is quite thin, of the order of 0.05-0.1mm, so I can't see how the bearing can be pressed into position without standing proud of the hub. Both bearings, and the spare, were new from ESM in 2016/7.
Am I missing something here?
cheers N

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33063, Eridge, Sept 2021 by Neil Evans, on Flickr
'69 Traveller, 1275, discs.
philthehill
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Re: Axle tramp

Post by philthehill »

The bearing is supposed to stand proud of the outer face of the hub and paper gasket by 0.001" - 0.004".
The hub bearing cannot be fully pressed home into the hub and be clear of the outer face of the hub.
I have just measured a original BMC UK made bearing and it is 17mm deep.
There has been some discussion on here as regards the correct thickness of gasket (use search facility) to use for each particular hub bearing application.
The thickness of the gasket will determine the amount of grip applied to (the bearing outer race) and between abutment shoulder in the hub and the half-shaft.
The gasket thickness should not exceed the proudness of the bearing from the hub. In fact it should be less to get the right amount of grip.

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ndevans
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Re: Axle tramp

Post by ndevans »

Ok thanks. So it's actually not far out then, as long as it's pressed home fully?
Is the BMC manual incorrect then, or have I just read it wrong?

Cheers N
cheers N

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33063, Eridge, Sept 2021 by Neil Evans, on Flickr
'69 Traveller, 1275, discs.
philthehill
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Re: Axle tramp

Post by philthehill »

BMC wksp manual section HH.2 is correct so I would suggest that you have misread the instructions.
The bearing must be pressed fully home in the hub before fitting the hub/bearing assy (and of course not forgetting the hub lip seal) to the axle.

I have now posted the procedure for determining the correct thickness of gasket required.
Last edited by philthehill on Sun Sep 29, 2019 9:38 am, edited 1 time in total.

pgp001
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Re: Axle tramp

Post by pgp001 »

Also pay attention to the correct way round for fitting the lip seal, it is easy to assemble it back to front and then you will end up oiling your brake shoes.

You are trying to keep any back axle oil that makes its way along the half shafts on the inside of the hub assembly, so the open side of the seal where the spring is fitted should be facing the hub bearing.

Phil
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ndevans
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Re: Axle tramp

Post by ndevans »

Thanks for the advice gents.

Here are a couple of pics of the bearings going back in.
IMG_20190929_172643~2.jpg
IMG_20190929_172643~2.jpg (1.65 MiB) Viewed 4509 times
N/S hub, with dial indicator zero'd on the hub face.
IMG_20190929_174743~2.jpg
IMG_20190929_174743~2.jpg (1.25 MiB) Viewed 4509 times
Bearing in place, dial indicator shows bearing is 0.2mm above the hub face (without gasket).
IMG_20190929_175740~2.jpg
IMG_20190929_175740~2.jpg (1.01 MiB) Viewed 4509 times
O/S hub, with bearing in position. The indicator was re-zero'd on the hub face, and shows the bearing race to be 0.3mm above the hub face, without gasket.
cheers N

Image
33063, Eridge, Sept 2021 by Neil Evans, on Flickr
'69 Traveller, 1275, discs.
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ndevans
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Re: Axle tramp

Post by ndevans »

I should add that I have the thin paper gaskets from ESM. They add a little under 0.1mm to the dial indicator.
cheers N

Image
33063, Eridge, Sept 2021 by Neil Evans, on Flickr
'69 Traveller, 1275, discs.
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