58 replies to this topic

[tiger99]

I believe that Ethel is right about needing to clean the seating, which I always do as a matter of course, using a pointed tool such as a scriber. Check very carefully that the bearing outer races are not showing roller indentations due to having been overloaded. If so, they are scrap, unfortunately.

When driving them in I always use an old outer race, cut through with the angle grinder to make it springy so it does not become jammed. I put the narrow edge of it against the new race and whack it with a hammer, or use some very large thick washers and a threaded rod to pull them in. When nearly seated, I always use the hammer and listen for the change in sound as the bearing becomes firmly seated. I have done many cars that way, not just Minis, and so far with no problems.

I always have used Castrol LM for wheel bearings, as well as the nipples and various other bits, and have had very few wear out.

[Fossy313]

Hello mate, some great advice, where would the roller indentations be?, and as for cutting the old one, do I need to take a slot out or just cut through it anywhere once? Surely it will just bind up to the same size and get stuck again?

[Fossy313]

tried again this morning, the races are definantly seated this time, however the wheel bearing is still stiff, if torqued all the way up, could it just need bedding in at all?, everything is seated properly, well greeced etc etc, i have torqued it up to 81nm and then backed it off to the nxt split pin hole, the wheel bearing moves in one hand but it does feel stiff when moving it, whats the best option, take it for a drive then see or?

[tiger99]

Do not under any circumstances drive it. The bearing will rapidly overheat, as will the stub axle, which will get soft and fracture, so you will lose the wheel. That is, if it does not sieze totally and lock the wheel first.

 

As to looking for roller indentations, they will be visible in the outer race where the rollers run.

 

To make my installation tool, you just cut right through the bearing outer ring in one place, so it can spring inwards slightly and not jam if it goes far enough into the hub. A hacksaw cut would be wide enough, but a hacksaw is not going to cut that metal, so I just go through with an angle grinder. A thin disc will do, or a standard one, the width of the cut is not important, as it only has to allow the outside diameter to relax by a thou or so, to prevent it being tight.

 

Edit: When installing a bearing you should always rotate it while torquing up, and if it starts to get slightly stiff, stop immediately and find out why before overloading it. A taper roller must always run with a very small amount of clearance, and must never be tight.

Edited by tiger99, 08 June 2013 - 10:18 AM.

[Fossy313]

Cheers mate, looks like in going to hae to take it apart again and see! There is a lot of people saying just to do it up until it gets tight then slacken it off? But I'm not confident doing that at all

[Ethel]

There are bearings that are fitted like that, but better to do the job correctly as it'll be designed with the clamping force of the torqued up nut. Were you doing the other side, what about swapping the bearings side to side? A manufacturing fault is possible. I'd expect the major dimensions to be checked, but an inadequate champfer to clear the root radius of the stub axle seems more probable.

[Fossy313]

Might be my last resort I guess? Swap the bearings over from the other side and see ...

[adam_93rio]

Tapered bearings expanse when in warm slightly so they should be tightened until tight then backed off until there is a little bit of play.
This is on other cars I have worked on but don't see why it would be different for the mini with tapered bearings

[Fossy313]

See, two completely different answers, one saying just till tight then backed off, another saying it has to be till 81nm?

[mini13]

definatly get the race out and give the hub a clean, a good scratch round it right into the corner, and a blast of brake cleaner, carb cleaner or some other solvent. and a blast of air if possible. also look for any dings  that may stop the race going in.

 

i always put a little wipe of grease in the hub to help the bearing race in, you'll see this ooze out when the race goes hard up against the spacer in the hub. you bust be sure the race is hard up against the hub!

[Fossy313]

Ok mate, will try again, thanks

[Fossy313]

Found out the problem guys, its the wheel bearings, minisports gepuenine specification wheel bearings arnt genuine timken ones, I tried it with my old set of timken and they work completely fine.....

[KernowCooper]

There we go another reason to not use anything but timken replacements

[Vipernoir]

There is a lot of work going on behind the scenes to sort out the various issues with non-gen bearings.

Two of the problems that have surfaced so far are inconsistant pre-load (the spacer is the wrong size) and the supplied grease is appalling.

 

If you can afford the genuine Timken bearings, do so.

 

If you can't, the non-gen can be made to work by modifying the spacer and avoiding the supplied grease like the plague.
 

[Ethel]

You could compare the widths if you have half decent measuring gear. Like I said, I expect they'll be the same as the originals. The difference will be in the finishing; no internal corner is truly square, there's always going to be some sort of radius (unless it's undercut, like an A+ crank), it's an extra machining job to put a bigger radius on an external corner to ensure it doesn't foul when the 2 are mated together. That or the taper faces will be ground and assumed to be correct without checking for inaccuracies due to tool wear, heat expansion....

 

Regarding backing off taper bearings, this would be valid if you were tightening the races against each other. With Mini wheel bearings you are leaning on your torque wrench like Billio  in an effort to clamp the inner races against the spacer - the spacer should provide the correct running clearance, and if it was slacker than intended it could allow the inner races to spin on the axle.