Front Wheel Bearings - Face Adjusted

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IslipMinor
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Front Wheel Bearings - Face Adjusted

Postby IslipMinor » Sat Mar 19, 2011 7:58 pm

What a difference! Like most other people I have had continual problems getting the front wheels to have the correct free play (i.e. none) to satisfy my own preference and more importantly the MOT man as well. I ended up changing the bearings sometimes after no more than 3/4,000 miles.

Today I fitted a complete set of new, face adjusted, SKF bearings. No fuss, just fitted everything as it should be and the wheels turn beautifully smoothly with no play, or stiffness at all. Got them from our local bearing suppliers, Brammer (was BSL, Bearing Supplies Limited). Will be very interested to see how they perform and last.
Richard



bmcecosse
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Re: Front Wheel Bearings - Face Adjusted

Postby bmcecosse » Sat Mar 19, 2011 8:09 pm

Code numbers please Richard!
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Fingolfin
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Re: Front Wheel Bearings - Face Adjusted

Postby Fingolfin » Sun Mar 20, 2011 2:26 am

Can someone from overseas get something like that? :wink:
The way to a man's heart may be making food, but the way to my heart is buying me car parts!
Come read about my Minor at An American Moggie.


IslipMinor
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Re: Front Wheel Bearings - Face Adjusted

Postby IslipMinor » Sun Mar 20, 2011 10:11 am

The bearing reference numbers are:

The NSK numbers for a 40 degree angular contact, face adjusted bearings are:
7303BEAT85SUN
7205BEAT85SUN

or for SKF the numbers for the same bearings are:
7303BECBP
7205BECBP

I bought them last October after a MOT 'advisory' on free play (again!), but have only just fitted them at the same time as new discs - ready for a track day tomorrow on the new 'extended' Silverstone GP circuit!. The only problem is the cost of the bearings - a total of £134 for both sides, including the oil seals and VAT. Only time will tell if it was worth it.

Fingolfin,

Shipping should not be too expensive, about the same as the VAT that would not be charged maybe, but not sure about import duties?
Richard



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Re: Front Wheel Bearings - Face Adjusted

Postby bmcecosse » Sun Mar 20, 2011 10:49 am

Thanks Richard. Bit too expensive for me - and I have never ever had any front wheel bearing issues - but then I sadly don't get to do 'track days' :cry:
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paul 300358
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Re: Front Wheel Bearings - Face Adjusted

Postby paul 300358 » Thu Feb 07, 2019 4:13 pm

For further information on this thread. I've just fitted new front wheel bearings which are the FAG equivalent of the 7303BECBP and
7205BECBP. The code numbers are


FAG 7303-B-TVP and FAG 7205-B-XL-TVP. Total cost for one side and a tube of LM grease was £67.

Paul

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Re: Front Wheel Bearings - Face Adjusted

Postby paul 300358 » Sat Apr 06, 2019 2:05 pm

Just an update on the above post, I had my car on one of the ramps at my nephews garage yesterday to replace a worn front hub. While it was in the air I had a feel at the other side front wheel bearing and found that there was plenty of play, so do not waste your money on the FAG wheel bearings as they have only done about 200 miles. I will end up buying a set of original RHP bearings.

oliver90owner
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Re: Front Wheel Bearings - Face Adjusted

Postby oliver90owner » Sat Apr 06, 2019 2:23 pm

Have you checked that it is, in fact, the bearings that are faulty?

paul 300358
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Re: Front Wheel Bearings - Face Adjusted

Postby paul 300358 » Sat Apr 06, 2019 4:49 pm

Yes, I had a quick look and the outer bearing looks like it has quite a bit of play, unfortunately I didn't have any spare bearings so I didn't want to remove them until I have some liquid nitrogen or an alternative bearing set. I don't think that its the hub as I had to hydraulically press the bearings in. The spacer is the correct size and the bearing appeared to fit fully up to the stub axle face.
The hub that was replaced yesterday had worn (original) bearings and the hub inner bearing face was worn, the inner bearing literally fell out.
I think that I will get a set ready and then have a good measure of the hub land between the bearing faces before refitting as if its worn the spacer will be too long for the hub and this will cause premature bearing failure. As I said in a previous thread, Bearings Impex of Crewe stock the original bearings but they are about £100 + vat per side.

philthehill
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Re: Front Wheel Bearings - Face Adjusted

Postby philthehill » Sat Apr 06, 2019 5:02 pm

There is no need to use any special process for the removal of the bearing outer race from the hub. There are two cut outs in the hub which allow for the use of a punch to drive out the bearing from the hub.


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Re: Front Wheel Bearings - Face Adjusted

Postby paul 300358 » Sat Apr 06, 2019 5:46 pm

Your right Phil, but using liquid nitrogen reduces the diameter of the bearing allowing it to be pushed out fairly easily in one piece. If the bearings are good they can be used again. If you drift them out you usually split the outer bearing to push the spacer over and access the machined channels this will leave small burrs on the race surface, if reused it probably wont last long.

Obviously the nitrogen will only work on the original hubs, new replacement hubs are machined out of bar and will have a similar coefficient of linear expansion as the bearings.

philthehill
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Re: Front Wheel Bearings - Face Adjusted

Postby philthehill » Sat Apr 06, 2019 6:08 pm

In many years of changing wheel bearings I have never had a damaged bearing race or seat or any related problems when drifting out the bearings.
We never used Liquid Nitrogen in the BMC garage just a good punch/drift which is softer than the bearing race or seat. The drift will get damaged before the race or seat.

What is special about your hubs that they need to machined out of bar?
Last edited by philthehill on Sat Apr 06, 2019 6:20 pm, edited 1 time in total.


paul 300358
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Re: Front Wheel Bearings - Face Adjusted

Postby paul 300358 » Sat Apr 06, 2019 6:17 pm

How do you access the machined groves with the drift without splitting the outer bearing and removing the spacer?

philthehill
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Re: Front Wheel Bearings - Face Adjusted

Postby philthehill » Sat Apr 06, 2019 6:35 pm

If required there is no problem in splitting the inner or outer bearing to gain access to the spacer and punch/drift recesses.
In many cases the inner bearing will fall to pieces when the hub is pulled off the stub axle.
Splitting the bearing is of no cause for concern if done carefully.
The ball bearings and cage can just be popped back into the races with a sharp tap.

I still do not know what is special about your bar sourced front hubs


paul 300358
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Re: Front Wheel Bearings - Face Adjusted

Postby paul 300358 » Sat Apr 06, 2019 6:50 pm

Nothing is special other than the difference in material, the bar stock will contract at the same rate as the bearings, so you gain nothing altering the temperature. The cast hubs contract at a slight different rate. I have access to liquid nitrogen so may as well use it to save damaging the bearings by popping the inners. Give it a try.

philthehill
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Re: Front Wheel Bearings - Face Adjusted

Postby philthehill » Sat Apr 06, 2019 10:40 pm

Fortunately my Minor is fitted with Marina hubs and stub axles so has taper bearings so easy to fit and remove.


paul 300358
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Re: Front Wheel Bearings - Face Adjusted

Postby paul 300358 » Mon Apr 08, 2019 5:26 pm

following Phil's advice I managed to drift the FAG bearings out without popping the outer bearing using a large copper drift and light taps. The bearings have axial play but I can't detect any radial play, so following Phil's other advice I have reduced the length of a spare spacer from 1.501 inch to 1.498 inch. I will give them a go on Wednesday and hope that the play has gone.
I'm just wondering if the bearing centres are a couple of thou bigger than the originals?

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Re: Front Wheel Bearings - Face Adjusted

Postby paul 300358 » Thu Apr 11, 2019 11:12 am

The FAG bearings were re-fitted with the shorter spacer but there was still play. So I've removed the bearings and fitted an old RHP set from a minor hub with a correct size spacer, all the play has now gone.
I did notice that the minor stub axle has a sharp corner where the inner bearing butts, The midget axle has a 2 mm radius. I wondered if this was due to a higher expected load on the midget due to it being driven by the young and reckless as opposed to vicars and nurses. Could this account for the lower torque on the minor bearings?

IslipMinor
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Re: Front Wheel Bearings - Face Adjusted

Postby IslipMinor » Thu Apr 11, 2019 2:44 pm

Paul,

The Minor stub axle is a different design to the Sprite/Midget, which comes directly from the A30/A35. There is no stress concentration in the Minor design, as it has a separate stub axle that presses into the upright, whereas the A30/35 based design is a one-piece forging, so there is a need to avoid a stress concentration in the corner where the diameter changes from the ID of the inner bearing, up to the oil seal diameter.

The hub nut torque setting for the Minor is 35-40 lb. ft., and was 55-60 lb. ft. on the A30/35/40 and early Sprite/Midgets, but changed to 25-65 lb. ft. later on, to allow the nut to be aligned with the split pin hole without going outside the recommended torque setting range. Since the design is common to both, and the bearings and spacer were the exactly the same from 1952 (A30 & MM SII) to 1980, when the last Midget was made, that is a much better value to use.
Richard



Edward1949
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Re: Front Wheel Bearings - Face Adjusted

Postby Edward1949 » Thu Apr 11, 2019 3:51 pm

This thread reminds me that Minors had a bit of a reputation back in the day for wheel-wobble at higher speeds, even after careful wheel-balancing. I always put it down to some subtlety of suspension design which exaggerated the slightest bearing play into an annoying vibration felt through the steering. I've owned other makes of car with much worse bearing play which had no perceptible steering vibration at speed. Strangely, my current 51 year old Minor (original spec, dubious maintenance history) has no steering vibes at 70mph. It has just-perceptible play at the rims which doesn't seem to matter. Could it be that modern tyres have more accurate natural balance during manufacture, and that 50 years ago the wheel balancing operative was making the best of a much less precisely made tyre?


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