Axle tramp

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pgp001
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Re: Axle tramp

Postby pgp001 » Wed Sep 11, 2019 11:03 pm

Yes way too much, I think you can be confident you have found the source of the clunking.
According to Haynes, the edge of the pinion flange should have between 1/32" & 1/8" free play.

Let us know what you find inside.

Phil

ndevans
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Re: Axle tramp

Postby ndevans » Thu Sep 12, 2019 7:23 am

I think I know what I'm going to be doing on Saturday!

Can anyone tell me what size the retaining nut on the diff plane is, please? The large central one, not the cardan shaft bolts. I have to remove it because the metal dust shield is damaged and needs beating back into shape.

Cheers N
cheers N
'69 Traveller, 1275, discs.

philthehill
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Re: Axle tramp

Postby philthehill » Thu Sep 12, 2019 7:47 am

1 1/8" A/F and torqued to 140lbf ft.

All the common nut /bolt sizes are listed in Mechanical - thread sizes and in most cases the tightening torque is also specified.


StillGotMy1stCar
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Re: Axle tramp

Postby StillGotMy1stCar » Thu Sep 12, 2019 11:12 am

I thought the 140 Lbs ft was for diffs with preload set by shims, did the later diff have a crush spacer that sets the pinion bearing preload?
If the nut is torqued up too tight will collapse the spacer further giving the bearing too much preload and alter the crownwheel and pinion backlash.
Perhaps it would be better to mark the nut with respect to the flange and the flange with respect to the pinion shaft you must get it back on the same splines. With nut and flange marks realigned the preload should be the same as before.
You will also have to reuse the straighten dust shield as the one on the duff diff may be a different thickness.
See link below with a previous posters experience.
viewtopic.php?f=4&t=69784&start=60
Regards John

pgp001
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Re: Axle tramp

Postby pgp001 » Thu Sep 12, 2019 1:07 pm

It might not be a problem with the mesh between pinion and crown-wheel, it could be other parts that are worn, half shaft splines for instance.
To have that amount of movement between pinion and crown-wheel it would have to be almost out mesh altogether, or a tooth missing, I suspect it might be something else.

Just go at it logically to identify what parts are moving in relation to each other, dont just rip it all apart before establishing what is wrong.

Phil

ndevans
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Re: Axle tramp

Postby ndevans » Thu Sep 12, 2019 2:12 pm

Worn half shaft splines has occurred to me, and I'll have to remove them before I remove the diff anyway. I've had them out in the last year or two, and I don't remember them looking worn.
I feel like I should replace the oil seal on the spare diff, as it's an unknown quantity, but maybe I'll put it on and see how it is. It'll be easier to get the nut off while it's in the car, anyway.
cheers N
'69 Traveller, 1275, discs.

ndevans
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Re: Axle tramp

Postby ndevans » Sat Sep 14, 2019 11:41 pm

Ok, seems like I may have a faulty hub after all.
I took to half shafts out, in preparation for removing the diff, and found that the drum screws and half shaft screws were a bit loose. I also found that the hub is loose on the bearing. It's the same both sides-there is a couple of mm play in the hub, axially, between the brake backplate and the bearing lock nut.

https://youtu.be/Lg6PiD-tf-s

When I fitted the half shafts and drums back on, there was virtually no play on the o/s, and a small amount, just detectable, on the n/s.
Both bearings and seals have been replaced in the last two years, by me, after one leaked so badly that it wouldn't pass the MOT.
So have I got worn hubs? Do I need to replace them, and of so, do I replace the bearings as well, given that they are only 2 years old, and have probably done under 3000 miles.
Cheers N
cheers N
'69 Traveller, 1275, discs.

pgp001
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Re: Axle tramp

Postby pgp001 » Sun Sep 15, 2019 12:23 am

It looks to me from the video that the bearing outer races have been spinning in the hubs and have probably worn them over-size.
If it were me I would be thinking about new bearings and some good second hand hubs, I had something similar on mine but nowhere near as bad as that. You have to get the end float correct when you re-assemble them, mine had gaskets that were too thick as well and it was causing too much end float and an audible clunk now and then.

However, I dont see how those bearings have anything to do with the diff backlash problem you showed us previously ?
Even if the drum and half shaft screws were a bit loose, it would all have nipped up when the wheel nuts are tightened.

Phil

ndevans
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Re: Axle tramp

Postby ndevans » Sun Sep 15, 2019 1:21 am

Well, that's what I thought, but all the wheels do it pull the hub tight against the half shaft. They don't actually prevent play, as far as I can see. Should the bearings be tight in the hubs, and not able to move back and forth in them?
I guess it's worth sorting the hubs out first before messing around with the diff. I am rebuilding my spare diff anyway, but that may go on the back burner for a while, if this proves to be the source of the clunking.
cheers N
'69 Traveller, 1275, discs.

philthehill
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Re: Axle tramp

Postby philthehill » Sun Sep 15, 2019 7:25 am

There should be no lateral or radial play in the hub or hub bearings. The bearing should be tight on the axle stub and in the hub. See wksp man illustration in the use of a puller to remove hub.
It is essential that you use the correct thickness hub gasket as it quantifies the lateral nip of the bearing in the hub - see wksp man for details. There has been some discussion on the message board about using the correct thickness gasket (use search facility).
There have been reports of rear hub bearings with excessive play on this message board in the past (use search facility) especially with C 3 bearings.
Always best if you can get NOS original BMC Minor/A35/A40/Sprite/Midget rear hub bearings though latterly BL/Unipart started to supply C3 bearings.
There has also been discussion (use search facility) on the use of sealed bearings in the rear hub.
If replacing the actual hubs it is better to use the later type with the rubber 'O' ring for better oil sealing.
I would also recommend using Allen headed countersunk screws for securing the axle shaft and brake drum.


ampwhu
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Re: Axle tramp

Postby ampwhu » Sun Sep 15, 2019 8:44 am

ndevans wrote:
Sat Sep 14, 2019 11:41 pm
Ok, seems like I may have a faulty hub after all.
I took to half shafts out, in preparation for removing the diff, and found that the drum screws and half shaft screws were a bit loose. I also found that the hub is loose on the bearing. It's the same both sides-there is a couple of mm play in the hub, axially, between the brake backplate and the bearing lock nut.

https://youtu.be/Lg6PiD-tf-s

When I fitted the half shafts and drums back on, there was virtually no play on the o/s, and a small amount, just detectable, on the n/s.
Both bearings and seals have been replaced in the last two years, by me, after one leaked so badly that it wouldn't pass the MOT.
So have I got worn hubs? Do I need to replace them, and of so, do I replace the bearings as well, given that they are only 2 years old, and have probably done under 3000 miles.
Cheers N

i suggested this further up the post.

2 options. this happened to me. either get hold of another pair of hubs, or use bearing lock to hold the bearings in place. I used green Loctite and the bearings wont move again. bear in mind people don't advise this, but engineering solutions are there for a reason. my engineering company use it on new machines and it works. Also once locked in, if the bearings fail in the future (doubtful as some cars still have original ones after 50 years) you will need another set of hubs. This is a cheap option and you have nothing to loose.


https://www.ebay.co.uk/itm/Loctite-641- ... SwwAdbBaBB

ndevans
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Re: Axle tramp

Postby ndevans » Sun Sep 15, 2019 8:52 am

ampwhu wrote:
Sun Sep 15, 2019 8:44 am
ndevans wrote:
Sat Sep 14, 2019 11:41 pm
Ok, seems like I may have a faulty hub after all.
I took to half shafts out, in preparation for removing the diff, and found that the drum screws and half shaft screws were a bit loose. I also found that the hub is loose on the bearing. It's the same both sides-there is a couple of mm play in the hub, axially, between the brake backplate and the bearing lock nut.

https://youtu.be/Lg6PiD-tf-s

When I fitted the half shafts and drums back on, there was virtually no play on the o/s, and a small amount, just detectable, on the n/s.
Both bearings and seals have been replaced in the last two years, by me, after one leaked so badly that it wouldn't pass the MOT.
So have I got worn hubs? Do I need to replace them, and of so, do I replace the bearings as well, given that they are only 2 years old, and have probably done under 3000 miles.
Cheers N

i suggested this further up the post.
You did, thanks, and it didn't seem to be coming from the wheels when I ran it with the axle on the stands. But I was wrong.
cheers N
'69 Traveller, 1275, discs.

ndevans
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Re: Axle tramp

Postby ndevans » Sun Sep 15, 2019 10:13 am

Question on installing bearings in hubs-do they need to be hydraulically pressed in?
I did it using a vice and the outside of an old bearing off the Micra, which was a good fit for the outer race of the Minor bearing. I pressed it home to the required depth, as in the BMC manual, and used a gasket & O ring that were the correct thickness. I don't remember there being this much play when I installed them.
cheers N
'69 Traveller, 1275, discs.

ampwhu
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Re: Axle tramp

Postby ampwhu » Sun Sep 15, 2019 2:56 pm

I do them in a vice as well. If the bearing seizes, then it turns in the hub. This is what happened years ago with me. Bearing lock solved the issue and is still on the car 10 years later.

ndevans
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Re: Axle tramp

Postby ndevans » Mon Sep 16, 2019 12:10 am

Is bearing lock a bit like thread lock? Does it still allow the bearing to be removed in future?
cheers N
'69 Traveller, 1275, discs.

philthehill
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Re: Axle tramp

Postby philthehill » Mon Sep 16, 2019 7:50 am

Loctite stud and bearing lock permanently secures the bearing to the housing or shaft and makes it very difficult to remove the bearing at a later date.

https://www.ebay.co.uk/itm/Loctite-Stud ... SwJkZdfT6C

There are other Loctite product available that may suit your purposes better and are not so permanent.

https://uk.rs-online.com/web/b/loctite/ ... lsrc=aw.ds


pgp001
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Re: Axle tramp

Postby pgp001 » Mon Sep 16, 2019 8:08 am

The application of heat (blowlamp) usually destroys the loctite bond.

I use it all the time when making parts in my model engineering workshop, it is very hand to be able to attach a temporary mandrel to a part to hold it whilst machining in a chuck or milling vice etc. Then once finished warm it up and the parts come apart again very easily.

I actually use a stronger grade for this purpose ie Loctite 601 or 638, only because I happen to have a big bottle of each.
I would not suggest using such a high strength on your hub bearings though.

Phil

philthehill
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Re: Axle tramp

Postby philthehill » Mon Sep 16, 2019 8:37 am

I have used the heat method to release and/or remove the Loctite but that Minor hub and bearing assy is a lot of metal to heat up.
Phil


geoberni
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Re: Axle tramp

Postby geoberni » Mon Sep 16, 2019 9:17 am

philthehill wrote:
Mon Sep 16, 2019 7:50 am
Loctite stud and bearing lock permanently secures the bearing to the housing or shaft and makes it very difficult to remove the bearing at a later date.

https://www.ebay.co.uk/itm/Loctite-Stud ... SwJkZdfT6C

There are other Loctite product available that may suit your purposes better and are not so permanent.

https://uk.rs-online.com/web/b/loctite/ ... lsrc=aw.ds
Totally agree. In my RAF career I encountered a wide range of different Loctite grades, because thread locking liquid might be used for everything from a little 8BA screw inside an instrument or gauge up to huge bolts on an aircraft structure.
There is a huge range of strengths across their product range.
Basil the 1955 series II

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Re: Axle tramp

Postby jaekl » 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?


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