7 replies to this topic

[Rich's trailer]

I want to try & source some compatiable shims to have control over the bearing tightness of the wheel hubs. This is for trailer that has mini hubs and wheel by the way and not for a car.

I know that if I just buy timken bearing it would probably remove the need for these but it also might not, plus I just think the mini hub is bad design. Tappered bearings should be adjusteable shouldn't they? If your going to have fixed torque then they should be plain bearings.

So.. could anyone help me please. I just need the inner & outer measurements of the orginal spacer.

Many thanks, Rich.

[Dan]

Moved.


No, tapered bearings as installed here should absolutely not be adjustable. The tolerances are properly designed out in the first place. The spacer or spacered race that comes with each set is selected to fit that specific set of rollers and give the required pre-load to the rollers when clamped into the assembly, assuming the rest of the parts are not worn. There is no generic set of measurements because the part is machined to fit the bearings it comes with. There isn't a separate part. Properly installed Mini rear hub bearings last for decades of service and can easily outlive the car. The only reason you would need to make further adjustments would be if other components were worn. If the shoulder of the radius arm is worn then the entire hub would be able to sit further in towards the arm. If the locator built into the hub is worn, the two outer races would be closer together and leave the bearing slack. The only real way either of these could happen is if the bearing had been ignored after a failure long enough to seize and spin the races in the hub or on the shaft. Further, the only way they could need additional spacing would be if the races weren't pressed in far enough because there was some dirt behind them. If all the parts are properly machined there is no adjustment required, it is taken out at the bearing factory.

[Ethel]

Just for completeness, there are taper bearings that are torque adjustable - the front hubs of Sherpa vans were held on by nuts at 5ft/lb. No suggestion you could do the same with your Mini!


.... an afterthought,

Since the tapers & balls fit the same stub axle, deducting the width of the taper inner races from the ball's should put you in the right ball park ( pun). Of course the material hardness will also be a factor.

[Rich's trailer]

Just for completeness, there are taper bearings that are torque adjustable - the front hubs of Sherpa vans were held on by nuts at 5ft/lb. No suggestion you could do the same with your Mini!

Yes, I had a Mk1 Fiesta which also had a torque setting for the bearings but it was to tighten to a set torque then undo a 1/4 of a turn (or something like that).
Also had a MK3 Golf and the wheel bearing tigthness was judged by how freely you could slide the washer side to side with a flat blade screw driver - that was a very good system for judging tightness.

All of these had a thick washer with a placement tab to stop a spinning bearing from being able to undo the nut (as well as the split pin).

The mini hub is so dependant on everything being right that it begs the question why it was designed that way, I mean surely a system that can accept a little adjustment would be better?
Personally I like plain bearings - there is no loading effect from torquing up the inner shell if installed correctly (not side loaded) and if you have play you need a new bearing.

I've read several threads on the web of people complaining about the rear wheel bearings in mini hubs. Having the ability to adjust the feel of the bearing seems a logical improvement rather than having to trust the bearing manufacturer can make the bearing to the exact tolerance required.

My hubs look fine and still had the orginal bearings in them when I changed them. I went to geat effort to clean out the hubs before installing the minisport bearing and also made 100% sure the out shells were firm against seats - yet they were very tight once installed & torqued.

[tiger99]

Your problem is that you bought cheap Chinese bearings from Minisport. They have been implicated in other recent threads here. If they are wrong, you should send them back and demand a refund. If enough people do that, they will lose so much money that they will learn the lesson and stop sourcing defective parts from China, or go out of business.

[Ethel]

Well the rear hubs weren't designed for tapers, they're a modification Cooper came up with. But one so effective it eventually replaced the original design. The front hub nut has more to do than tension the wheel bearings.

[Rich's trailer]

Your problem is that you bought cheap Chinese bearings from Minisport. They have been implicated in other recent threads here. If they are wrong, you should send them back and demand a refund. If enough people do that, they will lose so much money that they will learn the lesson and stop sourcing defective parts from China, or go out of business.

Okay - could you (or anybody) please give me an accurate measurement of a quality bearing (including the built in spacer). I can then measure mine and if substancially different I will know that this is the problem and will also have some evidence to go back to minisport with.
I have a digital vernier caliper which accurate to 0.03 mm - should be enough.

[Dan]

Also had a MK3 Golf and the wheel bearing tigthness was judged by how freely you could slide the washer side to side with a flat blade screw driver - that was a very good system for judging tightness.

Well actually I think that sounds like a pretty awful way to judge the load on the bearing. It depends on all sorts of things that would effect the friction between the parts, including the degree to which the parts are polished which is a much harder process to control than machining to a finished size. Nomatter what car it is and what the parts are, you have to trust the parts manufacturer to produce parts to specification. The simple fact is than in 41 years of production, this design was never really changed aside from the swap to taper bearings which was to cope with larger wheels and greater offset (and the later addition of an extra seal) and with over 5 1/2 million cars running on these bearings, they were never something prone to give trouble until very recently. Because they were simple to install and didn't rely on any subjective assessment of feel by the mechanic. Remember we are looking at this from 13 years after production ended and parts supply is now less controlled that when there were thousands of these cars coming off the line every year.

Edited by Dan, 08 April 2013 - 12:48 PM.