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MG Midget and Sprite Technical - Wheel Bearings Knowledge please

I recently replaced a front wheel bearing on my wire wheel midget because I noticed that there was some play between the 12 0clock and 6 Oclock position (ie top to bottom). That wheel bearing had done just 2000 miles.
Having fitted the new bearing and torqued it up it now felt fine. However after 200 miles the same issue has developed. I am confident that it is the wheel bearing and not a worn hub or king pin etc because I can both see the movement and feel it against a fixed point. The strange thing is that if I turn the wheel a couple of inches and feel for play again, there is none. If I turn the wheel further there's play again.
Is this a simple case of another duff bearing or might it be something else. Incidentally I had the original bearing from the MGOC and they sent the replacement FOC.
The box the bearing came in is marked 'Powertune' with a reference no. RGHK1142 (Made in Taiwan)
Any advice gratefully received.
Neil (K series)

Neil. That number is the same part number as Moss list for a front wheel bearing kit. I think everything is made in Taiwan or China nowadays, with varying degrees of quality.
How much play do you have? I usually spin the wheel as I'm torqueing up to try and get the bearing to seat properly. Is there any noise like a growl when you spin the wheel fast? That would indicate wear, but at 200 miles, I doubt it.

Bernie.
b higginson

Hi Bernie,
Thanks for the info about the bearing no.
There's no rumble from the bearing and it spins freely.
Neil
Neil (K series)

How much was the bearing kit?

To get a bearing to fit correctly the 2 bearings MUST BE a matched pair. This is described as "Face adjusted" a face adjusted pair of bearings will typically cost you £90 if they are not then they will always have play.

On top of this ALL modern bearings including tapers and face adjusted will have a further problem. The inner radius of the inner bearing will be too tight for the radius on the alxle. This can cause the bearings to not sit exactly flush with the axle root. This should not be a problem as it has been the case for many years but a few people have suggested that it could be the cause of axles shearing?

It is possible to still find some original spec bearings the 2 numbers you require are
3MJT17 and 34LJT25

I believe this chap has bought up all the old stock and can supply the original equipment bearings identified above

http://www.ransomeandmarles.co.uk/

Good luck
Robert (Bob) Midget Turbo

Looks like this can o' worms will never go away!

Believe me Neil, you are not the first with this problem!

When you get a little time read this:

http://smithtr6.com/bearings.htm

And take Bob's advice!
Dave Rhine ('78 1500)

Neil

If it's the wheel bearing, you should have the same play at 3-9 o'clock as 6-12 o'clock.

Play between 6-12 o'clock might be the kingpin; you need to jack up the susp and have another look.

As asked above, how much play?

Last time I replaced a bearing, I tried 2 suppliers that seemed to supply joke-shop items, before I had a better one from Peter May; it still needed 10 thou of the spacer to eliminate excess play (my brother is a bit picky on this at MoT time... it's MoT time at his garage in Sheffield at 7am tomoz!)

A
Anthony Cutler

Hey neil,

Have the exact same situation, only at 3 to 9 oclock, if its sitting straigt... (No PLAY) if I turn so the back side of tire is in the wheel well ...(NO PLAY), but if the tire front is inside the wheel well there is (PLAY)...vary odd, I havent investigated yet, and Ill deal with it when I rebuild the front end, But i havent seen that before It is a head scratcher for sure....Not sure if my story is related to yours,,, but it is a HUMmmm kind of thing.

Ill be following.

Prop


Prop

To identify if the play is bearings vs. some suspension component, apply the brakes and try moving the wheel. By doing so, you are making the brake disc or drum solid to the brake caliper which is, or should be, solidly mounted to the stub axle. If there is still play evident with the brakes applied, the issue is in the suspension. Is the play disappears, the bearings are likely at fault.

Peter C.
Peter Caldwell

Good little tip that Peter may use that on our website.
Bob Turbo Midget England

Thanks for the replies.

Bob. I understand what you are saying. Didn't know that however. MGOC charge about £23 plus VAT for a bearing set. Moss a fraction more. £90 is a big step up.

Anthony. My suspension was renewed entirely less than 5000 miles ago. New stub axle assembly with king pins, spring pan and all bushes. Also well greased.
Also "If it's the wheel bearing, you should have the same play at 3-9 o'clock as 6-12 o'clock". Nope, just at 6-12. However if I turn the wheel a couple of inches the play will stop at 6-12.


Peter. Carried out your suggested test. With front brakes applied, there was no movement in the wheel when rocked as before. Therefore, wheel bearing?
Neil (K series)

Neil,

3MJT17 and 34LJT25
Just got 2 sets from Bearings Impex (01270 582228) when I rang and gave the numbers was greeted with "For your Midget?"

2 sets £149.81 inc vat & delivery



David
David Hunt

Thanks David.
Why then, when there is a problem with Midget bearings, do the mainstream MG suppliers still sell ones not up to the job?
In fairness, I have had bearings in the past that have been ok. I don't understand this.
Neil (K series)

Neil,

Moss have change their supplier again - but once bitten.... I'd rather pay £70 once than £30 three times.

I suspect the mainstream suppliers are catering to a price sensitive market in the most part.

Thank the lord for the BBS and all those who donate their time and experience to help those of us who just want to "fit & forget"

D.
David Hunt

I contacted Graham Naughton the director of ransomeand marles
For 2 x 3MJT17 and 2 x 34LJT25 it is £210
inc postage(£10)


Amazing how expensive these are......

Jon


J WHITE

Yes, they are very expensive...one of the reasons I haven't resloved my bearing issue yet!

That's what happens when all the NOS parts have been bought up & all the new parts are SO inferior.


I'm sure with all the information & discussion brought up on this & other forums and all the new inquiries to Ransom & Marbles, these folks have become awfully proud of their LIMITED stock of bearings!
Dave Rhine ('78 1500)

I have just replaced the bearings in one hub with the correct 3MJT17 and 34LJT25 bearings from the source mentioned above, but I can still feel a little play. So how much is acceptable?

Tore
Tore

Hi Neil
Don't know if this is your problem or not - but some inner races don't have a big enough radius on the inside where it butts up against the shoulder on the stubaxle.
What happens is the bearing contacts down in the radius area before the bearing seats up against the shoulder properly, holding it out off the shoulder with nothing to hold it nice and square. If it's not seated properly the chance of bearing failure is increased.
If the bearings being supplied to you don't butt up to the shoulder a shim could be fitted between the bearing and the shoulder to get the bearing seated against the shoulder. Try your bearing on the axle and see if there is a gap there and if so measure it with feeler gauges and get a shim just a few thou thicker than the gap.
Hope this is of some help Cheers Willy
WilliamRevit

Thanks Willy.
That's a plan. I'll give it a go this weekend. It's strange but the nearside front bearing has been fine.
Neil
Neil (K series)

Yeah, - could be a slight difference in the manufacture of the two axles, or the bearings could be a tiddle different - just enough to be a pest
OR it might not be this at all but worth a look anyway.
Willy
WilliamRevit

Willy, I rstored the car from a poor state and in doing so renewed all the front suspension inc stub axles with king pins, spring pans, bushes, bearings etc. It was a couple of years before I got the car to an MOT. It has come back to me now that at the MOT the tester commented on some play in the front o/s bearing. I thought this strange at the time as the bearings were new. I didn't change them immediately but did so before going on a long journey with it this summer. This is where, upon return I checked the bearing and there was play and my earlier description applies. It may well be that I have a faulty stub axle. Hadn't thought of that. It might explain the problem.
Neil
Neil (K series)

Neil please do not let people confuse you, a too large radius on the axle will NOT cause play. The too large radius on the axle only prevents the inner race of the inner bearing from transfering its horizontal load easily to the hub. The play in the bearing comes from the inner spacer holding the 2 bearings in a set position. If the bearings are not a matched pair (face adjusted) then 49 times out of 50 the wheel will have play in it when assembled.

You can address this problem in 2 ways, either assemble, note the play, machine down the inner spacer so that the bearings sit closer together. that will cure the problem and many of us used to do that for many years but is a bit hit and miss and if you machine too much off the bearings will overheat and wear preamaturely.

Alternatively buy a pair of face adjusted bearings such as the ones noted on the Midget Register website.

The only problem then is that ALL modern manufatured bearings use the same radius on the inner race so every Spridget and Morris Minor that has had new bearings fitted has had this radius problem. Now the only thing the radius problem can cause is failure of the stub axle, now correct me if I am wrong but how many times have you seen failures of stub axles on a moggy or a Spridget? Not many, but if it is a concern then you can get both the play and axle failure problems sorted by fitting NOS bearings as noted above.

The one thing to note is that face adjusted bearings will cost at least £90 a pair so if some one sells you a kit for £30 then it will not be any good. And it is not because the bearings are manufactured in the far east that is the problem it is the spec of the bearings that is wrong.

If you want me to email you the original BMC drawings of the bearings which show both the inner race tollerance and the necessity for face adjustment then I will!

Why is this issue so complicated by everyone!!
Bob Turbo Midget England

Thanks Bob. I have made enquiries with a bearing supplier locally and they can supply the bearings you speak of for £40 each plus VAT.

Isn't it strange though that the bearing I fitted to the n/s has been absolutely fine and they came from the same supplier.
Neil (K series)

It certainly is but it can be possible that the bearings will fit if the tollerances are the 1 in 50. However what is more of a worry is that someone (like me) may have machined shorter your inner spacer in years gone by. If this is the case then the face adjusted bearings will be fitted too tight.

To check this you need to measure the inner spacer. It should be exactly the same as the raised section in the hub normally about 1.5 inches.
Bob Turbo Midget England

Hi Bob,

how do you get the bearings back out to adjust the spacer length?

It seems like the only way to press out the outer bearing is to press on the spacer, which pushes the inner race and blows the bearing apart and damages the balls and races.


Norm
Norm Kerr

Bob - Neil
I'm not saying the different radius causes play in the bearing
What I was working on was that if the inner bearing isn't seated against the shoulder of the stub axle there might be a chance that the bearing isn't sitting exactly square and therefore might wear prematurely and cause the play.
Also if there are and burrs or lumps in the hub itself from being damaged when removing the old bearings this could also stop the outer faces of the bearings from seating in the hub properly which could also result in play/wear issues Just trying to help Willy
WilliamRevit

Sorry Norm missed your post.

to remove the spacer you simply pull oit the inner bearing from the inner bearing (if that makes sense!
That means that the inner bearings outer race remains in the hub and the spacer can be pulled out the back of the hub.

By the way I would not do this now as I would happily fit a pair of face adjusted bearings rather than guess and modify my hub and spacer.

Willy I would suggest that because the bearing is almost an interference fit on the axle a slight burr would prevent the bearing from sliding into position and it could not possibly become scew irrespective if it sat against the shoulder or not? but that is only my opinion.
Robert (Bob) Midget Turbo

Hi guys,
I can't upload the text file on this website, so here's a link to the MG Enthusiast BBS where I've posted some stuff I've written recently, in my attempt to summarize everything known (so far) on this issue (and also, a hearty "thank you!" to everyone who has contributed to this so far, including those I found in the archives here).

http://www.mgexperience.net/phorum/read.php?3,1538651,1538651#msg-1538651

I welcome your input / advice / bearing part numbers.

Summary:
- fitting the OE bearings (2 x 3MJT17 and 2 x 34LJT25) is the "best" answer, but they are expensive.

- the new wire wheel hubs sold by several of the "usual suspects" have a big radius inside that makes it impossible to fit the OE 3MJT17 (outer bearing). I am researching another source for new hubs just now, one that is NOT used by Moss or VB. Will update as soon as I hear back.

- the outer race of a ball bearing CAN be machined, by a shop that specializes in it. The machining costs $100 per bearing (!). I found a shop in New York that does this for large manufacturing equipment (to very tight tolerances). But, again, that is a lot of money to add a radius. Especially if you've just spent between $200 and $300 for a car set already (what those OE RHP ones cost now).

Norm
Norm Kerr

Bob,

How do you pull out that inner bearing? Or, were you talking about using tapered ones when you said that?


Updates:
- in my post above I realize that I was talking about a NEW radius issue that has not been discussed much until now (an issue I found, with new wire wheel hubs from VB and from Leacy), and my mentioning this new radius issue may have been unintentionally confusing for anyone trying to follow this story who already knew of the stub axle clearance concern with non-OE inner bearings.


- the original radius issue (at the base of the stub axle) is resolved by using those expensive OE RHP bearings. Or, it could be resolved by buying cheaper bearings that fit in every other respect and having them machined to a 2mm radius (for $100 a piece) and then shimming the whole lot for proper clearance (since other bearings are not face adjusted, shimming really should be done). A lot of work, to be sure, but possibly cheaper. After all is said and done, maybe not cheaper. I guess it would depend on the cost of those "other" bearings compared to the high price of the OE RHP bearings.


The upshot of all this bearing story is this: the front wheel bearings ought to last the life of your vehicle (or, at least 100k plus miles), so most of us should only ever need to mess with this once, if ever.

The bearings that were not fitted correctly are the ones that will wear quickly, and will then need re-doing.

According to John Twist (University Motors), these bearings do not need to be pulled and re-greased periodically. He advises instead to just add some fresh grease to the outer bearing anytime the hub is pulled (for, say, a new disc rotor, or a kingpin re-do).

When the hub must be replaced (worn out wire wheel splines, for instance), or the bearings re-done (for whatever reason), my goal is to find the best solution folks can follow, to be sure of a correct fit, to do it just that one time.


Norm "trying to get my bearings" Kerr
Norm Kerr

OK, thanks for the contributions. I have another question by way of follow up.
Having undone the castellated nut on my wire wheel hub, the hub came off the stub axle easily. No puller was required.
Suspecting I may have a faulty stub axle I then trial fitted just the new inner bearing by sliding it on to the stub axle. It slid on with no resistance at all and in fact the inner race spins on the stub axle.
I thought this should be an interference fit and not spin on the stub axle. I also note that I have pitting on the surface of the stub axle. I suspect that once the bearings are fitted into the wire wheel hub the play I can feel, when I rock the hub, is due to the stub axle not being spherical. Any views please?
Neil (K series)

Hi

by bearing design convention, the bearing should only be a tight fit to one of the mating parts, typically the part that does not rotate, relative to itself (in this case, it should be tight to the hub and loose to the stub axle).

But, "tight" and "loose" need definition, because too tight will actually squeeze the bearing too much, just as too loose will allow galling, which is what I think you are describing when you say "pitting".

If it is so loose that you can feel play, and in your case, have galling to prove it, then you want to have a machine shop re-size your stub axle diameter for you (weld up and machine back down to the right fit).


Norm

PS: by "spherical", you mean "cylindrical", I think.
Norm Kerr

Norman,
What I meant to say is that I think I have a flat spot on the stub axle which means the bearing can 'wobble'. I am summising that the pitting has caused this.
I have been in touch with the supplier and they have agreed to exchange the stub axle assembly. The nearside stub axle and bearing has been fine. It's just the offside one which has given the problem.
Neil
Neil (K series)

gotcha, I am glad they'll sort it out for you.

Also, I mis-spoke when I said, "weld it up", I should have said "spray metal buildup".

":o)


According to my measurements, the bearings ought to fit to the hub with about 0.001 ~ 0.002" interference (bearing OD x Hub ID), and fit to the stub axle with a line x line fit (both the bearing ID and the axle OD ought to be the same diameter, though I have seen a 0.001 ~ 0.002" clearance somewhere around the axle diameter when trying to use a digital caliper (a caliper is kind of "floppy" to measure stuff this closely).

Interesting little side note:
the purveyors of MG parts (Moss UK, MGOC, Leacy, Sussex, etc.) are selling the inner and outer bearings under the part numbers of GHB 128 (outer) and GHB 129 (inner). I just found out today that these are apparently NOT the original Austin Morris part numbers for those bearings. The original part numbers used by Austin/Morris/BL, back in the day, for the RHP bearings that are the right shape, were 2A 4178 (outer) and 2A 4299 (inner).



Norm
Norm Kerr

Neil
Glad you found something--
Very impressed that your axle supplier is standing by his product and resupplying another after a couple of years,-- Hope it all works out Willy
WilliamRevit

Thought I should update this thread.
As you know I had play in a front wheel bearing in the 12 to 6 oclock axis. I tried replacing the bearings and this made no difference. Some suggested it could be the poor quality of current bearings and I should go for face adjusted ones. I didn't do this. I was able to exchange my stub axle as the stub wasn't in great condition. Still no improvement. I have now put on a new wire wheel hub, courtesy of the MGB Hive at £55 inc VAT and hey presto, no more play. I did think about loctite but I opted for a new hub instead. I am chuffed. Thought I would share this as someone else might have a similar problem.


Neil (K series)

Yep worn hubs have been diagnosed on several cars on this side of the pond.
But the disk wheel hubs are not available....

looking in to ally ones now
Onno Könemann

This thread was discussed between 24/08/2010 and 08/10/2010

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.