Tapered wheel bearing question

[62Countryman]

I am the process of acquiring all the parts for converting my brakes from Drum to Disk (7" Cooper). Mini shops are selling the Timken brand tapered bearings and the price is not cheap. Are the bearing sets they mini bits dealers selling a matched set? By that, I mean the bearing and the bearing race can be purchased separately. Purchasing the parts by themselves is cheaper than the bearing kit BUT I do not know if the bearing race and the bearing have to be sold asa matched set.

[guru_1071]

the bearing and the race are a matched pair.

one wears the other

[62Countryman]

So you are saying that I have to buy the kit verses purchasing the exact same Timken part numbers (race and bearing)?

[guru_1071]

ive never heard of bearing races been sold on their own.

bearing factorys will spin the new bearing cage & balls in the race to make sure they are a quiet & smooth matched pair.

i suppose buying individual parts and saving a few quid, then having to do the job again when it howls like a cat organ will only serve to underline the saying 'pay cheap, pay twice' mantra.......

[62Countryman]

I have a set in front of me now (came from my friends mini) and I am able to locate a source that sells the exact same parts (1 race and 1 tapered bearing) both made by Timken. I haven't been able to source the spacer but I am still looking. The race cost more than the actual bearing. The cost of purchasing the Timken parts is a big savings. I can purchase the parts for both wheels for the price of 1.

[Frogeye61]

It used to be that one could purchase outer races separately. One could for example purchase a new front hub for a rear wheel drive car, WITH outer races already installed.

Quite often an inner shaft diameter is specified and an outer bearing diameter is specified. They have standard sizes for the taper and different outer races can be used to provide a bearing set that fits any application. They are in this case "pieced together" from new parts. Tolerances of the taper surface are *very* small.

With reference to the Mini, both the inner and outer diameters are already specified, so a finished pair is available. In practice, one could change an outer race without problems, provided the bearings aren't worn. Hopefully the bearings aren't worn anyway and if it is the entire unit should be changed.

Normally it's cheaper to by the set than try to piece things together.

BTW, the dimensions of *nearly all* bearing surfaces is a standard originally developed by SKF.

[Michael7]

You may find old stock in N. America of the individual inner and outer races, which are commonly called "cups and cones" in the bearing trade over here. Anyone holding old stock may be able to sell them cheaply, but new stock will be affected by the very recent worldwide increase in the cost of these from Timken.

My understanding is that the spacer in the Timken-made full sets is custom matched to the inner and outer race to achieve the specified overall thickness of the bearing assembly once in place. In fact the spacers used to display markings which varied from one to the other. I suspect this level of care is carried out only by Timken, the original supplier. I don't think imported (Asian) taper roller sets will have custom sized spacers.

Of course, the machined-in race stop within your used swivel hub could no longer be to original specification as well, so even a matched set may not give the design spec preload. A good shop can set them up properly by feel, but it takes some trial and error.

[Frogeye61]

I think I remember getting a small set of shim spacers in various thickness's with the wheel bearing kit. Sort of like this
http://www.mgexperience.net/article/mgb ... arings.jpg