8 replies to this topic

[Mini Man Sam]

This my be on already but have done a search and not found it.

I think the front wheel bearings need doing. There is a fairly loud noise coming from the general direction. It is not a knocking and does not realy change under load (cornering etc) but is fairly constant. Have turned engine of and freewheeled in neutral and noise still there.

Have not yet checked for any play etc with wheels of ground but what i want to know is how easy is it to change. Do you have to follow the haynes comic and remove struts etc or can it be done in situe.

May find that it something as simple as disk rubbing when I investigate just trying to get one step ahead of the game.

Car is a 1990 998 mayfair with 12 inch wheels and disks.

Any advice will be greatfully recieved.

[Guess-Works.com]

Any work on the hub is best done with it removed, and is essential when dealing with the wheel bearings, basically as you have to undo them to get the driveshaft out...

Once the hubs are off it's just a matter of drifting them out with a punch and hammer, and putting in the new ones... If there is any spin in the bearing reace to hub fitting, then a new/replacement hub will be required.

As for what type, the arguments may follow, but IMO, if you have disk brakes or are using wider than std wheels then you should be using TIMKEN bearings and not the rollerbearings.

but back to the bearings themselves, I would jack the car up and have a feel, grasp the wheel at the 3 and 9 o'clock positions, and push and pull with each hand alternately... any movement ( which is not the steering rack ) will signal a loose/dry bearing.

First of all undo the hub and inspect the bearing ( and if you wing ballbearings and you on disks, change them anyway !! ) re grease and re-assemble.. torquing up the drive shaft nut to the specified rating on the manual... the rock may dissapear, if not, then new bearings.

Edited by GuessWorks, 20 June 2005 - 12:37 PM.

[Ade]

Timken ones?? Are these stronger than most or something? I have to do one side of mine but if there are stronger ones than standard available I might as well do both sides..

[Guess-Works.com]

Timken bearings are tapered rollers and not balls. Because the bearings are angled then there is natural holding action create in the hub.

[Ade]

And the natural holding action does what? I'm curious as to whether it makes them last longer? Or is it better for wider wheels?

[Guess-Works.com]

When the bearings are torque’d up, it's like two cones being pressed together with a shim between then this prevents sideways movement of the races within the hub. The Ball bearing races are not thrust bearings like those using in differentials, but deep groove bearings, and therefore can be subject to wear under sideways loads...

This is my opinion and I am aware that there are different schools of thought, but the overriding thought is, BL and Austin Rover were tight gits, therefore why would they install a more expensive bearing type when they switched to disks, unless it was absolutely necessary.

[dklawson]

This is another point where I think we are separated by a common language. Technically, both types are roller bearings. However, the common arrangement uses a pair of ball bearings. What you are referring to as the Timken bearings is specifically a tapered roller bearing (and a specific manufacturer at that).

The tapered bearings are preferred in large part because they have greater contact area which allows them to support higher loads. However, the Mini is the first car I've had where tapered roller bearings could be used on the front, driving wheels. Most front wheel drive cars I've worked on use heavy duty, double-row, angular contact ball bearings. The hubs and bearings are larger to accommodate the higher loads. Tapered bearings on non-Mini cars are very common on the rear hubs. On non-Mini cars it's common to torque the bearing/hub to some pre-determined value (which frequently corresponds to when the bearing starts to create drag). Then the wheel is "spun" by hand for a few revolutions and the bearing nut is loosened a specified number of flats and the cotter pin is inserted to keep the nut in that position. The Mini is obviously different in that the spacer between the bearings must be the precise length to give the desired preload and/or play.

Well that's my bearing lecture. The upshot or summary is the tapered roller bearings have higher load capacity and are generally therefore longer lived and a good investment.

[Turbo Nick]

i personally use the ball race bearings in my disc brake hubs. i'm running 13x7 wheels and i found that i was going through the taper type bearings in 6 months. changed to the older style and they have been fine for 2 years, checked em for the MOT yesterday and there's a little play in em so i'll change em and they'll be good for another 2 years

[bluebottle]

my jem runs on wide 10" wheels and has gone through loads of timken taper roller bearings, the life seams really short on them.
my mates hillclimber went through a set in just 6 events, which in road terms is only about 15 miles!......i've also heard that some miglia racers change thiers after every 2 races.