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MG Midget and Sprite Technical - Front hub bearings ( yet again, it seems ! )

I have fitted new bearings to the front hubs, but when the castellated nut on the stub axle is tightened, the hub seizes on the stub axle. Can anyone explain why this is happening please ? I was confident that the bearings and distance pieces had been fitted correctly, but now my confidence is draining away !!
Thanks in advance for any help.
Myles
M W Sutherland

Myles,

Did you manage to swap the distance pieces from one side to the other. I would expect them to be matched to the hub and so swapping them could lead to what you describe. Could also be they weren't driven home fully. Is one side tight and the other loose.
David Billington

Hi David,
I may well have done. I didn't realise that the distance pieces would be matched to the hub, so it is perfectly possible that I swapped them over in error. Thanks for your help.
Myles
M W Sutherland

Distance pieces are not matched to the hub.
Most likely a PO or garage took a bit off the spacer last time to get the slack out.

Shim it up or get a new spacer
Onno Könemann

Hi David, I've not heard of distance pieces being matched to hubs before. The ones that I've measured were within 0.001 of being 1.5".

Myles, which bearings did you fit?

Also, x2 on David's question about confirming that the bearings were driven all of the way into the hub (only press on the outer race, never on the inner, of course, when driving them home).

Crazy question: did you fit new wire wheel hubs? If so, there have been a bad batch floating around that have an incorrectly machined pocket for the outer bearing. It will not allow the bearing to be fully seated and will bind on assembly. I got a set like that from Leacy (UK), and a set like that from VB (US). Finally, I got a good set of hubs from Moss (US). All three sets were brand new, and looked like they were made by the same outfit (there was a small, white sticker on each of them that was clearly applied during manufacture, and they all looked the same).


Norm
Norm Kerr

I don't know for sure if the spacers are matched to the hub or not, Onno says no, but it's an application where having matched items could be applied if the economics favoured finding a size match as opposed to consistently having to machine the hub and spacer to a very close tolerance. It's not something I would want to risk finding out by trying it as removing the bearings usually destroys them when the inner pushes out of the outer race.

Myles,

Maybe you just got a bad set of aftermarket bearings that are too tight. Shame the originals are not more readily available, welI think are from a few sources but not necessarily cheap.
David Billington

Thanks for all your comments guys.

The hubs are 4-stud ones, not wires. I bought the bearing kits from a reputable MG parts specialist in SE England, from whom I have had many parts that have been fine, so far at least. My mate has a bearing press, which we used to fit the bearings. The new bearings did not, however, have the word ' thrust ' on them, so we fitted them by mating the faces that matched those on the old ones, which did have ' thrust ' on them, against the bearing seats. He has done some before so I feel pretty sure he put them in correctly, and the press should have ensured that they were fully home and seated correctly, I would think.

I'll get the hubs off and check the spacers. Are they meant to 'float' a little or be a tight fit between the inner faces of the two bearings ?

I'm assuming that the bearings are preloading incorrectly as the hub nuts are done up ?

Myles
M W Sutherland

Myles,

I've always found that when off the stub axle the spacer can float around a bit. That'll be due to no load on the inner races allowing them to float in the internal clearance of the bearing so not nipping the spacer. When fitted to the stub axle and the nut done up then the spacer is solidly clamped by the races and if the assembly then binds the spacer is too short.
David Billington

That's interesting, David. Putting a shim or two in may solve the problem, or fitting two new spacers ? Maybe the old ones have been machined, like Onno suggested earlier in this thread. At least, it's a place to start.
Thanks again.
Myles
M W Sutherland

Non of the reputable MG supplieres supply the correct face adjusted bearings.
In previous threads possible supplieres have been mentioned (but they are expensive)

I think it is a miss match of slightly fettled spacers and slightly off bearings.
Try some shims and with some trial and error you will get it right
Onno Könemann

Do both hubs seize up when tightened ?

Assuming the bearings are fully pressed in and the correct way around it must be either incorrect bearings or both spacers have been machined - which is more unlikely both machined the same amount.

Can you measure the spacers accurately ? - I can check against some here or do you have access to try other spacers.

I do not think spacers are 'hub matched' as they were sold seperately not as sets - BMC would have machined them accurately !

R.
richard boobier

I have removed the hubs again using a proper puller, and the same thing has happened to both i.e. the inner bearing has remained jammed on the stub axle, or at least the inner portion of each bearing. The balls and races were still there too, with the seals. The remains of each bearing are stuck fast, and one is fully home on the stub axle whereas the other has pulled off about half an inch before becoming stuck fast.

Have I done something elementarily wrong i.e. dumb !

As regards shims, where do these fit please ?

Sorry to be so clueless. I'm on a steep learning curve here !

Myles
M W Sutherland

Hi Myles,

Here is an article that goes through the front wheel bearings in detail, I think that it answers your questions. Scroll down to see the (several) illustrations that (hopefully) make it easy to follow.

http://www.mgexperience.net/article/mg-midget-wheel-bearings.html

if you have any questions, please don't hesitate to ask



Norm
Norm Kerr

I thought that the problem is that many of the current aftermarket pattern bearings do not seat properly. The bearing should have a radius on its inner edge where it buts up against the back of the spindle. On some, the radius is insufficient to allow the bearing to push fully on. Apart from creating a weak point this also would cause the bearing to bind when used with the correct spacer. I believe that some spacers may have then been machined to correct the binding without addressing the real cause of the problem.

Guy
Guy

Guy,

Not sure youre correct about not seating on the spindle would cause binding.

The hub inners are tightened together i.e inner bearing centre/spacers and outer bearing centre to form a solid mass - this then allows the outer races and hub to run round the inner - with the face adjusted bearings providing the clearance.

True its not good if the inner bearing face dues not meet the shoulder, as twisting can/could occur.

(sorry this is no help to the problem !)

Myles where about in Devon are you ?

R.
richard boobier

There is an added problem here because if in removing a bearing from the spindle it separates,(as is often the case) pressing it again can often result in bruising and damage to the bearing surface. When a hub + bearing is torqued up and has the correct end float first time there is never an issue - but if you have to reassemble more than once - because it's either too loose or too tight - the resultant bruising will often mean the bearing will need replacing again or in the short term.
F Pollock

As I understand this, the radius is on the stub axle shaft, only to prevent a weakness that would exist if it was a sharp angle instead.

The Radius on the inner bearing, is there so that the face of the inner bearing can butt up flush with the verticle of the stub axle. Then when the whole assembley is torqued correctly, it adds to the strength of the shaft.

If the radius on the inner bearing is too small, the bearing is not able to butt up flush.

Then:

1) A poetntial weakness exists, due to the reduced contact surface area between the inner bearing face and the verticle of the Stub axle.

2) The Hub is moved outwards causing the Brake Disc to run closer to the caliper, instead of centrally.

I can't see how the inner bearing could twist. The shaft would prevent this happening because it's a pretty close fit on the shaft. Unless the either the shaft diameter was reduced or the inner bearing diameter was increased.

So the binding must be due to either the bearings being too close to eachother under torque (short spacer), or some other cause.
Lawrence Slater

For poetntial, read potential, unless you are in a prose like frame of mind :)
Lawrence Slater

Ahh Richard. Yes you are right. I was thinking if the inner bearing is moved outwards by a few thou because it doesn't seat properly, it would reduce the running clearance for the balls in the race. But of course the whole thing then moves outwards as you say. It is still a problem in reducing the stiffness of the stub axle (or rather, not increasing it) but it shouldn't then have a direct impact on the bearing causing it to bind as I imagined.

Lawrence, there was a problem with early cars with the stub axles shearing. It isn't that the shaft prevents the inner bearing from twisting, although it does in a way. Its more that the inner bearing, clamped up with the sleeve, effectively increases the spindle diameter and prevents the whole thing flexing.
Guy

Firstly, thank you all again for ongoing help - much appreciated. I am going to get the 'face adjusted' bearings from R & M, despite heavy comparative cost, I think.
Secondly, many thanks to you, Norm. The article is comprehensive, to say the least ! Some of it is too technical for me to fully understand, but it will certainly help me when attempting to reassemble everything once the new bearings arrive.
Lastly, to answer you, Richard, I am in Exeter. Anywhere near you ?
Cheers once again.
Myles
M W Sutherland

Thanks Guy.

When you say early cars, do you mean that the first spridgets didn't have the spacer to increase the shaft strength? And where did they sheer? I don't doubt you, but I've never read about that before.
Lawrence Slater

Lawrence,
I don't know the mechanical details, but I think it was related to the way the stub axle was fabricated. It was a fault experienced on some rally sprites. I could look it up, unless someone else can fill in my memory gaps.
Guy

No that's ok Guy, I just wondered how early as in Mk1,2 3?

And if you say only rally sprites, then it doesn't sound like it is something likely to happen to a road car.

Mind you, with these stub axles now approaching, or already 50 years old, maybe we should all be a bit worried about the strength of the axle shaft. In which case the better the bearing fit with regards to the radius, the better, irrespective of any play in the bearings from an MOT point of view.

Lawrence Slater

Lawrence. You just triggered something in my mind. I read above and have read on several threads before, that some bearings have been manufactured with the wrong radius on the inner bearing. Now, you mentioned that the stub axles are approaching 50 years old, but as we all know, we can get complete exchange stub axle/king pin/ bottom pan assemblies from various suppliers. My question is, are some of the "new" stub axles(if indeed they are new) being made with the wrong radius at the inner end as well as the bearings? Sorry to throw another hand grenade into the mix!

Bernie.
b higginson

Myles,
If you are going to get face adjusted bearings, measure your spacers or get new ones because as has been mentioned above they may have been shortened in the past. As Norm states above they need to measure 1.5" to within .001". Not ensuring this may result in failure of your new rather expensive bearings!

Trev
T Mason

Myles,

I live in Clevedon, North Somerset, but currently working in Exeter during the week on a major construction project (have family in Exeter).

Did you see Dave Prices post regarding a Masc initial meeting in Devon - next one will be at Ashburton - you don't have too be a club member - just turn up and say hello.

My phone number is 077907 26285 if you want a chat / pint etc.

richard boobier

Bernie,

You'd hope they were new stub axles, but they are all in fact exchange. I can't find anyone supplying new ones.

So any previous damage or alteration gets passed on to the next owner. Maybe if you have good ones, it's better to buy a pin reamer, and keep your own.

They are indeed getting very old for the function they perform. If they were an aircraft part, they would be grounded lol.

For such often changed parts i.e bearings and pins/stubs, you'd thing there would be a new supply, and of the correct fit too. They'd have plenty of customers to make it worthwhile I'd have thought.
Lawrence Slater

Lawrence,
The reference to breaking stub axles is in "Spritely Years". JS mentions something about a casting hole on the early (A35 Parts Bin) sprite stub axle which may have been the culprit. But I have heard of other, more recent failures.
Guy

Just to confirm as we do everytime this subject comes around.

2 faults are present with new front wheel bearings.

the first is that if you use non face adjusted bearings, the ones that are supplied by various so called specialists and costing anything below £50 a set then you will end up with too much play when the job is finished and your car will potentially fail MOT. The only bearings available to rectify this are either NOS originals or the more modern 40 degree angular contact. I wrote on this extensively almost 2 years ago.

The second point is the problem our American friends identified and they suggest cause broken stub axles (I personally am not convinced by that but the facts about fit are correct when compared to the original drawings I supplied to them) The inner radius of the stub axle can be manufactured at 2mm. ALL modern bearings of that size (Whether tapers or any angular contact equivalents) will be manufactured to 1mm tollerance. Thus if both dimensions are adhered too then the fit will be less than absolutely perfect and whilst not causing any other problems may contribute to stub axle failure. To date I have never seen this occur!

The ONLY bearing that fits this radius perfectly is the NOS bearing currently being sold by someone who is using the R&M name.

I am personally happy to fit the 40 degree face adjusted but I can see why the NOS bearings can be desirable whilst stocks last. Both 40 degree and NOS bearings are expensive so buyer beware of cheap alternatives.

Regarding the problem experienced above only 2 things can cause it.

Either the spacers have been machined (simply measure them with a vernier, they should be very close to 1.5 inches) or and I suspect this is the reason, the outer races have not been fitted correctly into the hub. Either they were not belted in hard enough or some foreign body is holding them proud.

I agree with others that now you have pulled the bearings apart then they may not be much use as possibly they were not anyway
Robert (Bob) Midget Turbo

I've measured the two spacers, and they are both spot on at 1.5 inches, so it looks like the second of Bob ( Midget Turbo )'s reasons is the likely problem.
I thought that by using the proper press the bearings would be seated properly, but maybe not.
However, the fact that the inner bearings have jammed themselves onto the stub axle would tend to suggest that they didn't have the correct inside measurement to start with, surely ?
I am using exchange stub axles, but if they are all 'reconditioned' rather than new, would this not suggest that, if anything, the stubs would be smaller than 'original' rather than larger i.e. tending to confirm that the problem is with the inside measurement of the bearings ?
I am resigned to lashing out on the expensive, correct, type of bearings, and hopefully all will be well with those.
Many thanks to all once more.
Myles
M W Sutherland

Just to clarify that although most people seem to have trouble with non face adjusted bearings being too slack, they can just as easily be too tight. What you get will depend on the relationship of the tolerances between the outer and inner race. This is the reason for face adjusted bearings, which makes the face to track centre dimension identical on both races.

Trev
T Mason

Robert (Bob)

When you fit the 40 degree bearings, do you pack/shim the inner bearing, to compensate for the less than perfect fit to the radius?

Or have you left the small gap?
Lawrence Slater

Hello Lawrence

I fitted the 40 degree angular contact bearing a good while ago now and have not fitted any since.

The issue with the inner raius was brought to my attention by a guy called Tom from the states who was trying to rectify this issue as he believed it to be responsible for the stub axle breakages. For some reason the Americans o not seem to worry about excessive play caused by non face adjusted bearings yet as we in the UK are far too aware it is the MAJOR problem for us with this issue causing many MOT failures.

However as tated when this was brought to my attention I looke at the original drawings I had of this arrangement and realised if the tollerances were at each end on the axle and the bearing manufacture hen possibly a gap could exist between the inner race face and the stub axle face. As I said I am not convinced this is a major issue however it is not exactly as designed.

However it ought to move the centre line of the disk out by 1mm but looking at my disks mine run exactly central in the caliper suggesting that my hub is in the correct position. I do note that I had considered a 1mm shim on the stub axle would certainly correct any potential problem but I have not found the nee for this.

I have known a few enthusiasts who have since fitted the 40 degree angular contact bearings without shims and without further issues who are now very happy bunnies. :)

Robert (Bob) Midget Turbo

can't see it anywhere on the thread so can someone tell me how much a set of 4 of the r&M bearings would cost please?

graeme
graeme jackson

200 quid for 2 Inners and 2 outers. I've just asked them, as I have play on one side of the newly reassembled ( < 3000 kms ago) of my midget.

*sigh* It's a lot of cash for bearings.

Has anyone made alloy hubs machined to fit taper bearings (one thread I stumbled across this morning mentioned a 3.5mm radius KOYO bearing that fit the stub but didn't fit the hub :( ) since there's a lot of expense on a bunch of NOS bearings that will run out some day, I guess, and lightening of unsprung mass can only be a plus point... :)

P.S. KOYO bearing mentioned here : http://www.mgexperience.net/phorum/read.php?3,1205925,page=2
OrangeSpyderMan

Hi bob,

Thanks for that.

I have to strip my stub axles down this year sometime due to play, and it's a long time since I removed/fitted wheel bearings. Probably the last time I fitted them I bought originals, so I assume I have never encountered the problems attributed to the replacements.

I do have a little play in the wheel bearings, but it has been there for years and years, never getting any worse. I use a very friendly, and 60's car knowledgable, MOT tester. So maybe that's why I haven't had MOT problems so far.

Judging by your experience then, rather than go through the hassle of play and shimming, I think if I can't get the NOS bearings, I too will fit the 40 degree type, since they are of similar cost.

200 quid for bearings. Hmmmm.

So at about 100 quid per side, it aint as cheap as it used to be to do front wheel bearings.

Normally I would balk at spending such sums for replacements, when the originals were so cheap. That feeling of being ripped off springs to mind. And many on here think that it's too much to spend too.

However, people are prepared to spend relatively huge sums getting sills replaced, or respraying, or making dor gaps exactly right etc etc. Horses for courses.

My own view is that these are modern bearings, and whilst these are expensive when compared to the originals, you will likely only need to fit them once.

If you keep the car for even 5 years after fittting, that works out at only 40 quid a year. That is naff all compared to the amount of money spent on petrol each year. Just about a tank of petrol a year. Nothing really.

Of course I have a different view of my sprite, compared to the views of others of their own cars.

To me, it's a souless collection of metal plastics and rubbers, with a bit of organic material, some of which is human, caught in the cracks. The only purpose of which, is to provide me with pleasure whilst driving.

I don't care too much about aesthetics. I have always been function over form. So circa 200 quid for bearings is well spent, and the bent rear wing and poor paint job can stay as it is. :)




Lawrence Slater

Lawrence, I wish we could take your post and make it a "stickie" (one of those posts that appears at the top of the forum), because I couldn't agree with you more and your sentiment applies to so many things about owning an old car equally well.

Sort of, "the philosophy of faded paint, and shiny internals".

Norm
":o)
Norm Kerr

Blimey, thanks Norm. :)

You must be careful though, agreeing with me might get you a bad name LOL.
Lawrence Slater

I have followed this thread with interest and although it's probably been covered before and is lurking somewhere deep in the archives ( I have to admit I haven't checked), but has anyone any experience of Speedwell's tapered bearing conversion? In particular, does it require any machining to work? <http://www.speedwellengineering.com/suspension/tapered-front-wheel-bearing-conversion>

Peter B
Peter B

Their web site claims that it doesn't require any machining, but I've never seen one in person, or heard back from anyone who's tried it.

Speedwell's web site, also, is mysteriously silent on the subject of the inner radius, and it is hard to tell from their photo if theirs is large enough.

"Poets have been mysteriously silent on the subject of cheese." - Gilbert K. Chesterton

Norm
Norm Kerr

Peter

For us in the UK a taper bearing modification will cure the main problem of play in the front wheels, but it will not cure the inner radius problem as all modern bearings of this diameter will be made to modern engineering standards and will probably be about 1mm the same as all others.

The taper mod whilst curing the play problem is not a good solution as it is not a good solution. A twin deep groove bearing with inner spacer is far stronger and is far more efficient. The majority of modern cars use this set up but unlike the Midget have a double row deep grove bearing made in one piece rather than have to set 2 individual bearing up with a spacer. Tapers are a cheap alternative in the motor industry and the last I saw were rear wheel bearings on a ford Fiesta! cheap and cheerful.
Robert (Bob) Midget Turbo

Thanks Norm and Bob.

I half expected those answers so I think I'll avoid that method when my turn comes to replace front wheel bearings, and swallow hard and buy the R&M ones.

Thanks for the advice.

Peter
Peter B

If I've followed this correctly then with the non faced replacement bearings from the usual suppliers, there is a 1mm gap between the bearing and the stub axle face? So why not include a suitable 1mm shim/spacer with replacement bearing kits to be used as and if required?
Surely it can't be as simple as that can it?

Jeremy
Jeremy 3

Hi,

No it seems it's not that simple from what I have read.:(

There will likely be play in the bearings that you have to shim for (it seems most do), AS WELL AS, a gap at the radius, that you can "chose" to shim for, -- however this radius gap, might or might not move your disc too close to the caliper.

Better to bite the bullet I think in this case and pay the circa 200 quid.
Lawrence Slater

Thanks Lawrence, I've a set of non faced bearings in my spares drawer so they'll be pressed into service this time. Be interesting to see how long they last though...

Jeremy
Jeremy 3

Jeremy,

Can you check to see what the radius is on the inner radius of the inner bearing. I asked before whether the bearings being supplied had the correct radius but not the correct adjustment and didn't see any reply. Certainly the industry standard bearings have too small a radius but bearings are made for stub axle use with larger radii. I've seen a set for a VW Beetle and a similar set for a Porsche and both had significantly larger radii on the inner radius of the inner bearing where the bending load is at its greatest.
David Billington

I don't know how to make it clearer?

Non face adjusted cheap bearings will leave the wheel with play in it. This may cause it to fail MOT.
Robert (Bob) Midget Turbo

Robert,

I have no issue with that, what I was wanting to find out was whether the current replacement bearings, available from the usual suspects, have the correct large radius on the inner bearing inner race.

I see the R&M bearings as being an expensive option but the correct one. The SKF or NSK ones you gave details for before have a radius that conforms to standard industrial bearings and so is too small in which case they can be used but should have a shim between the inner bearing and stub axle so the inner race seats against the correct face rather than the small radius touching the larger stub axle radius.
David Billington

That is right Dave and there is nothing to suggest that any run of the mill bearing of this size would have nothing but a standard 1mm diameter.

With this in mind for quite a number of years we have had Spridget owners and Moggy owners fitting bearings that have not sat flush with the axle face. To my knowledge this has neither caused axle shearing nor disk clearence with the caliper. (Moggy has drums) So it seems strange to me that the issue that had caused Tom originally to look at the problem in the USA was the fact that he fitted bearings that had caused the disk to interfere with the caliper? I am wondering why was that?
Robert (Bob) Midget Turbo

Hi Bob,
I wonder if it could have been an extra large radius on one that caused his caliper to rub? When Tom and Pete measured a large number of stub axles at Pete's shop, they reported that they found anywhere from 1mm to 3mm on them (with the majority at 2). Probably the folks who've had no troubles had closer to a 1mm stubby, and the ones with the most trouble had much larger?

This would be a good reason to measure the bearing fit each time, if using NSK bearings, to make sure that the shim used does actually provide the support intended. (note, however, that the thicker the shim fitted, the more likely that the grease seal's lip will "fall off' of its sealing edge, as there isn't a lot of overlap to start with)


The fact that there have been some stub axles fail, over the years, indicates that there is a need for some care with this structure. But, on the other hand, I do have to admit that the fact that so few of them have failed, and some folks driving around with these ill fitting bearings, wheel wobble, and some even with no spacer at all, makes it seem that the original design had a fair amount of margin.

Unfortunately, it is difficult to say how much margin. All we can say for sure is that the system is stronger when set up as designed, and that it might still work for a long time if it is not.

My biggest concern is that the most likely form of trouble would be under fatigue, meaning that a failure could happen after a great many miles, making it hard to see the direct case and effect of this bearing fit situation.


Norm "bearing with it" Kerr
Norm Kerr

Norm, surely the extra large radius they found would not foul anything but allow the flat of the bearing centre to sit squarely against the flat load face of the stubaxle.

As I understood it it was too small a radius, holding the flat face away from the axle load face that was/is causing bearings to permit wobbling instead of making the necessary stability. This would also possibly allow the hub to run out of line with the caliper openings even though I wouldn't expect it to run so far out that it caused real problems.

Maybe as so often I have it wrong about all this, no doubt all will be revealed soon.
Bill 1

David,

I'll check the radius in the morning and see if I can post a photo as well. I'll also see if there's a 1mm spacer kicking around in the garage.

Jeremy
Jeremy 3

Is there any way to measure a radius, as small as the one on these bearings, without a gauge?
Lawrence Slater

Interesting comments above about the simple answer. The simple answer would be for one of the leading suppliers to buy the correct bearings from Orinoco who have them made (or go to the manufacturer direct). If they had them made in say batches of 50 the price would drop significantly. They do it with several other parts so no excuse not to really.

Trev
T Mason

Trev, you are correct, there is no excuse for them not to. Moss, or at least the MGOC should have been on this by now!

Lawrence, it can be tricky to measure an outside radius accurately. One trick is to use some modeling clay, press it over the shape, then cut the bit of clay in half to get a clean section of the shape (a thin scale is often sharp enough to make the cut), and then extend the straight portions until they meet and measure from the tangent of the curve to the extended, straight line to get the radius (harder to explain than it is to do).

Fussy, but accurate.

A borrowed, or purchased radius gauge set is very handy to have access to, but clay does work in a pinch.


Norm
Norm Kerr

Yep Sadly Bill I am afraid to say you have not understood the problem correctly (you are far from being alone howvever)

""As I understood it it was too small a radius, holding the flat face away from the axle load face that was/is causing bearings to permit wobbling instead of making the necessary stability""

The wobble as you refer to it (play in wheel bearing) is caused by non face adjusted bearings!

The inner radius problem is thought to cause failure of the stub axle and possibly as in Tom's case the disk running out of line with the caliper.

The only way present manufacturing techniques could deal with this problem would be for a small bearing manufacturer to buy from NSK etc. 40 degree face adjusted bearings and regrind the inner race internal radius. This is common practice for this kind of issue. However this would not be a cheap solution and as can be seen from these discussions people would not be prepared to pay the price and convincing them of the issues that cause this price would be a nightmare! So no hope.
Bob Turbo Midget England

Bob,

I also read (can't remember where now) that to re-engineer the radius, can cause damage to the bearing faces. Something called brinelling. It seems the grinding causes the balls to jump around, and can albeit minutely, dent the otherwise smooth surface of the bearing.

So that appears to be a possibly unreliable fix if true.

Have you heard of this, or have I mixed it up with another problem?

Norm, thanks for explaining the clay technique. I think I understand, but maybe I could find a cheap radii gauge instead . :) I think I'll take a look on Ebay and see how cheap/expensive they are.
Lawrence Slater

Cheers Bob, knew there was something of that in it and knew I wasnt taking it all in. The radius factor that threw me is something I would personally treat with a grinding wheel to get clearance on the inner of any bearing but I did recognise there'd be more to it after all that


So we agree that proper face Adjusted Wheel Bearing sets are what is needed, purchased in bulk from NSK?

All I need to do is convince Ron Leacey that there's real money in it

Did I say ALL I need to do?

doh

I may take a drive down to see him in a week or two, I need a gasket set for my engine soon, preferably with a Payen head set. It's "clean up Lara's act" time at last this winter.
Bill 1

If this affects all spridget and moggie owners too, then if a reasonable guesstimate could be made of the user base, it should be possible to work out the potential profit in getting batches made. I would think.

But does anyone have any real idea of how many of these cars are actually out there?
Lawrence Slater

Someone will have the link to the database that says how many if each car there are out here

I think it was several thousand Midgets

More thousands of Moggy Mynahs and all the others

Must be quite a target area

Found the link

http://www.howmanyleft.co.uk/

7896 Midgets
14394 Morris Minors

If you want a surprise look up the Sierra

Bill 1

Where did all those sierras go then? Heaven. Maybe all the spridget and moggie owners nicked all the g/boxes, and they had to be scrapped lol.

There are more MKII consuls than sieras, that's really great. :)

Well that's quite a few spridget/moggie owners, so there must be a decent market there I would have thought.
Lawrence Slater

Hi

Hi Lawrence, regarding your question about machining: I found a machine shop (in New York) who does this kind of machining on a regular basis because, often, in heavy machinery, there is a situation that no one manufactures exactly what is needed to repair an otherwise useful piece of old equipment.

Unfortunately, they charge $100 per piece. Not an issue for a manufacturer repairing a multi-million dollar press that only needs a new one about every 40 years, but no cheaper than buying from Orinoco, so I dropped it.

They use very special grinding equipment to keep the vibration down, and special rubber dampening rings clamped on to keep the balls from moving around while doing it.

When the bearings are originally made, the balls and the inner race are frozen and the outer race is baked so that there is clearance to assemble them. I suppose that someone COULD work out a heating/cooling jig to do something with already assembled bearings to get them apart without damaging anything, then you could safely machine the larger radius. The trick is to not exceed the temperature at which the metallurgy of the outer ring would start to change (blow torches need not apply).

As Bob said, the most straightforward solution is a bulk order with Orinoco to manufacture a few hundred sets for someone like the MGOC, and then the MGOC sell them out to Moss and Leacy and Sussex and B&G, etc. for a small mark-up. Maybe then the price would be about half, or less, of what it is now, for the face-adjusted, large radius bearings our cars need every 80,000 ~ 100,000 miles!

The trouble is that there are probably only about a dozen Midgets and Minors, each year, who actually NEED these parts. That could make the return on investment pretty lean, for whomever undertakes this noble effort.


Norm
Norm Kerr

As Norm states there ae companies who specialise in just this sort of problem and do grind bearings to suit applications. The company who NSK uses do this by utilising a new bearing of as near spec as possible then modifying it to suit.

Why do NSK or SKF not manufacture them? there is no call for this specification! :)
Robert (Bob) Midget Turbo

Looks like when I come to get a new set I'll either be buying the correct items from R&M, or getting NSK or SKF and adjusting them with the toolpost grinder to the correct radius.

The other option would be a set-up to measure the bearing play and working out the shims required to get the correct pre-load prior to installation. As most information appears to indicate the bearings will be loose that would mean a shim behind one of the inner races to take up the play.
David Billington

Thanks Norm. So it's possible, but not really worth it then as Bob and you said.

Just a case of accepting that in this instance, it's better to pay the piper. And it's a pretty decent tune after all.

If it was only a case of the radius, I think I too might also look at having a go with a mini grinder at opening up the radius, on a CHEAP non faced bearing set. (Assuming there is sufficient metal there to remove, without weakening the structure of the race).

But you would still be left with main problem of the play.

It seems to me that the time spent trying to get the shims right, could be better spent earning the money for the face adjusted bearings, or going for a drive or down the pub :).

Also, if the bearing wears a little after fitment and use, you could have to do the shimning again. And from what people say, you have the problem of removal each time, which damages the bearings when they come apart.

For all that though, if I had a cheap set lying around, out of pure pigheadedness and money ?savingness? (i'm tight really), it would be an interesting even if futile excercise. :)
Lawrence Slater

Its worth mentioning that if you do decide to do any machining on a bearing it will need to be thoroughly washed out afterwards to ensure no foreign matter has got into the bearing.

Norm, in my time in the industry we never froze and heated the races or balls to assemble them. Depending on the number of balls , most have room to fill them with balls on one side before the cage is installed. There are several other techniques for types that this doesn't work for. There is a lot more to it than meets the eye. For example I bet not many people know that we used to make each size of ball in 15 sizes, from -.0007" to +.0007". This means that you can machine the races to a small tolerance but have exactly the same clearance in any bearing.

Trev
T Mason

Trev,

The heating cooling makes some sense as I was wondering how they assembled the bearing with machined brass cages. Do you know how that would have been done.
David Billington

David, a lot of it depends on the depth of the track, as obviously a shallow track is easier to fill than a deep one. For ball bearings with brass cages many had a filling slot almost the size of the ball machined in the outer race on one side and a jig slightly distorted the outer race to get the balls in. Roller bearings have no such problems as the cage is in two parts that are rivetted together after assembly.

Trev
T Mason

Is that R & M bearings of Dundee (http://www.rmbearings.co.uk/) or Ransome & Marles bearings of Newark on Trent (http://www.ransomeandmarles.co.uk/) who call themselves R & M on their website?
Dave
Dave Brown

Its the second one. They have various websites under the old names, but they are actually called Orinoco Bearings. The first site is nothing to do with them.

Trev
T Mason

Thanks Trev,
I have just ordered mine.
They have been inundated with orders thanks to this thread/forum and have run out of stock. They are expecting more in early October but most of these are taken. They will be getting more in in November but the price will have gone up by then. Sorry, I should have asked how much they will be.
Dave
Dave Brown

Dave,

You might ask if the volumes are increasing due to the recent publicity whether they can do them cheaper. Hopefully they'll help support these classic cars and not try profiteering.
David Billington

Yes, I've just ordered a set, and have had the same feedback..

BTW - nice to meet Onno @ Angouleme :)

Take care,

OSM
OrangeSpyderMan

This thread was discussed between 10/09/2011 and 20/09/2011

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