Hello everybody,
as we know the rossa has mini front roller bearings on the back and outer CV joint from a 1000cc mini.

every since ive had nelly she has RAPIDLY worn out the nearside rear bearing.
ive put one in every 2 years - so that's 5 in ten years.
this is clearly wrong.
the other 3 bearings have not been a problem.
(that's two timkens at the front and another roller bearing on rear offside of course)
ive replaced the hub carrier, outer cv joint and drive flange with NEW parts -
and its STILL wearing out the bearing RAPIDLY.
the only thing I havnt changed is the actual driveshaft
could it be the driveshaft?
shurely not.

the other thing I want to do as im fed up of this problem is change the bearing for a different type.
can I put a Timken bearing in there? does anybody have experience of different bearings at the back of a rossa??
I don't mind changing the outer CV for a 1275cc one but can that be done??

many thanks for your time in answering these queries . .
best wishes
peter in Manchester

ps ive had experience of bearing hassles with my classic mini way back last century and I know that
everything has to be straight and true and the outer bearing racemust be properly seated etc etc . . .
I don't have excessive spacers - just the 1 inch built in ones.

Yes you can fit a set of timken taper bearings in there without modifications, I have always run Taper bearings on my coupe, bothe when it had a drum setup, disc setup and even when i mixed a drum set up with the larger disc cv.

Neil

The only time I came across a problem like this was from a distorted swivel hub.

The bearing locating recesses had packed down unevenly and the bearings were seating too deep and off square.

When you say the bearings are wearing out ,how are they failing? What are the condition of the balls and outer bearing surfaces when stripped down?
Most problems can be traced back to the swivel hub,distortion or out of specification
as previously posted.

I have found that the preload spacer are not all ground to the same thickness !!,the 1"
spacer. Not tightening the hub to the correct torque can result in a lot of flexing of the drive flange on the CV joint and wreak this ,enlarge the hub and fail the bearings.
I have experienced this on my car .Used distorted hubs that do not locate the bearings correctly will result in on going short bearing life expectancy..
I hope this helps, let us know more detail
PiltV40

The last time I fitted bearings they didn't have a separate central spacer. Each bearing had an extended inner race and they met in the middle when correctly tightened.

you people are the best! many thanks for all the replies!

I agree with all the comments and im chuffed that I can put a Timken in there.

the symptoms are nelly has ALWAYS worn out her nearside rear wheel bearing in no time.
I changed the drive flange , outer cv and hub recently (summer 2011) and it has had no effect
still wearing out bearing in no time. that new bearing had integral spacer.

after reading your replies my conclusions are:
1. there was something wrong with the hub before I replaced it.
2. ive done something wrong with the new (2011) assembly or the new hub also has a problem

heres the TWO POINT plan:

ONE. new roller bearing arrives this week and I will carefully assemble it into the hub.
is there anyway I can test for bad geometry?
im thinking if the resistance to turning is different from my good hub ive got a problem . .

TWO. if all is well then its jobsagoodun stop here.
if it wears out again then im gonna buy ANOTHER hub and put a timpken in it

what do we think people?
am I sucking on diesel? or am I sniffing glue?
many thanks for your replies and assistance.

ive had a think, and im gonna go straight to a Timken bearing
in the hope that it is better.
I found this on the "ausmini" forum (Australian minis) :

Assembly of Timken style tapered roller bearings to Mini front hubs (both drum and disc type)
NOTE- special equipment is needed- if you don’t have it, take it to somebody who does.

1. Clean the hubs out, check for undue wear on the centre web from bearing cups spinning. If bad, find another hub. Fit the new cups, ensuring they seat against the web. If slightly loose use Loctite 609 on the outside of the cups.
2. Check the new bearings are a neat sliding fit on the C/V (are on drive flange, with drum type). Remove any burrs with 220 wet/dry paper. If the C/V or drive flange is grooved, find another.
3. Assemble the bearings, spacer, C/V and drive flange without the seals and without grease.
4. Fit the nut and washer, torque up to 60lb/ft for drum C/Vs and 150lb/ft for disc C/Vs.
5. Rotate the drive flange by gripping it with finger and thumb, if it feels slightly tight but spins without any jerkiness that is OK. If it is tight and jerky when turned slowly, the spacer is too short. If it is loose and can be rocked even slightly, the spacer is too long.
6. If there is looseness (the usual problem if any) set up a dial gauge on a magnetic base or bracket, aligned with the end of the C/V. Push and pull the CV to establish end float present. Then machine or surface grind the spacer by (end float +.001”), this will give .001” preload when assembled. eg if it has .005” end float, grind .006” off. The spacer must be accurately machined parallel, do not try and do it by filing or using an angle grinder. Reassemble and check again rotation again.
7. If the bearings are tight and jerky you will need to find or make a spacer that is too wide, then assemble it, and proceed as in [6] above.
8. When you are happy with the rotation torque, disassemble, grease the bearings, fit the seals and reassemble.
Properly done, the tapered rollers last for a long time. My car had them replaced by me about 85,000 miles ago using this method, they are still fine.

these Australians are straight talking blokes and I think us GTM owners like them.
I will let you know how I get on . . .

Also worth noting the conical washer, this need to be in good condition, also lube it with engine oil when fitting, It says this in the haynes manual and is often overlooked, even I have missed this in the past it makes a big differeance to where the nut ends up when torquing and therefore resulting in more clamping

Neil

Hi again
SKF failure statistics show 36% bearing failure is due to poor lubrication and 34% are due to excessive loading.You can normally understand what type of failure mode has taken place by examining the races. I have overloaded mini hubs by excessive front wheel offset and additional spacers ,ever Rover was guilty of this.

If the correct running tolerances can not be achieved this can result in additional loading and chatter that probably breaks down the lubrication film. The hubs from minispares
I have found to be dimensionally correct for bearings with inbuilt spacers or the older spacer configuration

I have purchased some new hubs that have been machined out of tolerance .
and I have resorted to buying s/h hubs originally supplied by BMC in serviceable condition.
Install the bearings correctly and you should have no problems .
Regards PiltV40

many thanks for all the info !
im in agreement with all your words!
Mystery is solved - I got up early and stripped down hub ready to fit taper timpken bearings.
discovered my drive flange was completely and totally "out to lunch"
it looked like a metal rat had been gnawing at it for weeks!
so im defo an idiot for fitting my roller bearing at the wrong preload.

so set off for minisport in padiham in my mates mx5 (yes that one!)
wow! a snowy wasteland ! with ten abandoned cars and two abandoned buses!!
got a new drive flange for £22! marvellous
on the way back all the cars etc were being collected so that's good.

rebuilt the hub with new drive flange and new taper bearings.
now I don't want to tempt fate - but it feels "right" there is the right amount of resistance to rotation that you get with a "proper" fit taper bearing.
(ive had incorrect bearing spacers like mentioned earlier so I know what a "wrong" taper bearing is like.)
I did of course inspect the hubs and they seemed fine.

so at this stage im very pleased - it all seems sorted.
jobsagoodun. hopefully

I will use taper bearings all round in future as they are stronger.

best wishes everybody . . . .

just to add all is still good with wheel bearings
which is great.