Rear hub gasket

[biomed32uk]

Interesting, I do need everything, well the seal as I already have O ring and gasket but thats no issue.

The bearings fitted are R&M LJ35s.

6207 is an equivalent, and I can get them from simply bearings from quite a few manufacturers SKF, FAG, NSK, KOYO as either standard or C3.

I cant imagine the minor hub getting that hot in normal conditions. Anyone know what the specs of the LJ35s would have been ?, my findings conclude they are standard ??.

What are / have others fitted, how awful is the play induced by a C3 bearing ?.

[ndevans]

Can I ask what is a C3 bearing, and how is it different to the standard fitting?

Not sure whether the ones I fitted were C3 or not, but they were moving within the hub. The hub may have been worn, which may have caused the movement-some bearing lock has cured the movement.

[paul 300358]

C3 bearings have a small amount of play in the bearing race to allow for expansion when warmed up, the external dimensions are all the same.

[geoberni]

I've been reading this with interest since I was going to replace my half shaft gaskets after disturbing them replacing the brake cylinders
viewtopic.php?p=668949#p668905

However, having seen the difference between what was in there and the new ones, I've decided to leave well alone.

20210627_125708.jpg (591.31 KiB) Viewed 2286 times

[philthehill]

With the thin hub gasket you may have to use more than one gasket to get the right bearing nip.

[ndevans]

I thought the thin gaskets were the correct thickness? My hub bearings were loose in the hub, I suspect more because the hubs themselves were worn. The thin gaskets haven't been a problem in terms of oil leakage.

[philthehill]

There is no such thing as the correct thickness of gasket. The thickness of the gasket will depend on the amount the hub bearing protrudes from the face of the hub. See wksp manual for details.

[geoberni]

I thought the thin gaskets were the correct thickness?

There is no such thing as the correct thickness of gasket. The thickness of the gasket will depend on the amount the hub bearing protrudes from the face of the hub. See wksp manual for details.

I think I understand it now, and it comes back to a comments by Phil back on page 2

The outer face of the hub bearing should be proud of the outer face of the hub as per stated in the wksp manual.
You can get suitable/different thickness gasket paper in different thicknesses from 'e' bay.
That proudness is what grips the hub bearing and stops the outer part of the bearing rotating and removes the possibility of lateral movement of the hub.

Section HH2 of the manual contains a small para as follows:

Gasket.JPG (58.68 KiB) Viewed 2229 times

So it doesn't specifically state the 'adjustment' is via the paper gasket, but if the bearing is correctly fitted, I guess gasket thickness is the only other adjustment available.

I'm sure Phil can confirm or correct me on this.

[philthehill]

The thickness of the gasket determines the nip (or preload) of the bearing outer race into the hub.
These are the extremes:-
If the gasket was too thick the bearing outer race could move in the hub.
If the gasket was too thin the half-shaft flange could be distorted.
It is not just a case of fitting the first gasket supplied - there has to be some thought as to the thickness of gasket required.
It can be taken as read that the gasket must allow the bearing to protrude the required 0.001" - 0.004" beyond the hub and gasket when fitted to give the correct nip.

[LaughingBoy]

E.S.M. parts website says the thickness of the original gasket was 0.006" which seems correct - at least for me :

I have 0.008" clearance between the hub outer face and a straight edge positoned across the outer face of the bearing, so deducting the median of 0.002" (i.e. how proud the bearing should be from the hub & gasket) means that I need a gasket of 0.006".

I guess this could vary from hub/bearing to hub/bearing but a 0.006" gasket should be in the right ball-park.

All the gaskets I have bought in the past (and fitted without too much thought re clearances etc) have actually been around 0.026" - over 4 times too thick! E.S.M also tend to send out the thicker ones still so if anyone does order them make sure you ask and get the right thickness for your car.

.. having seen the difference between what was in there and the new ones, I've decided to leave well alone.

Geoberni - your photo above shows the 2 thicknesses of gasket. Your used one looks to me like a 0.0026" gasket and the new one probably 0.006". Would be useful to know where you got it for future reference.

Personally I would rather err on the thin side to ensure that the bearing is gripped by the half shaft.

Graham

[geoberni]

Geoberni - your photo above shows the 2 thicknesses of gasket. Your used one looks to me like a 0.0026" gasket and the new one probably 0.006". Where did you buy it?

Personally I would rather err on the thin side to ensure that the bearing is gripped by the half shaft.

Graham

Graham,
my gaskets came from ESM.
As my Electronic Vernier only reads to 0.00, all I can say is they are less than 10 thou, since I couldn't a reading on it.

[LaughingBoy]

OK, thanks geoberni - almost certainly 6 thou then.

[philthehill]

Make your own gasket with the required thickness of gasket paper.
Making a rear hub gasket is an easy task - all you need is a small ball pein hammer and use the ball against the edge of the holes to cut the gasket.
Various thickness of oil resistant gasket paper is available on 'e' bay.

https://www.ebay.co.uk/itm/141462465314 ... SwNJpbftXw

[ndevans]

Make your own gasket with the required thickness of gasket paper.
Making a rear hub gasket is an easy task - all you need is a small ball pein hammer and use the ball against the edge of the holes to cut the gasket.
Various thickness of oil resistant gasket paper is available on 'e' bay.

https://www.ebay.co.uk/itm/141462465314 ... SwNJpbftXw

I use a largish ball bearing and a washer to fit the stud. Place the gasket with the hole position marked over the holes in the washer, place the ball bearing on top, then either tap with a hammer, or, if you're careful, place the whole "sandwich" in a vice & close up.
But then I like doing things the hard way!

[oliver90owner]

But then I like doing things the hard way!

You most certainly do! Mechanics used to make most gaskets in the manner described by PTH for many years before ‘gasket sets’ and even separate gaskets were commonly available.

There are also hole punch sets available for the job - I even have a set for cutting shapes other than circular holes - which is still easier than messing around with ball bearings, washers and hammers - but it will work, so just carry on as you are…

[ndevans]

In fact, until we cleared out my dad's house, I didn't possess a ball pein hammer, so I had no choice really. Seeing this has reminded me that I now have one, so I might just make a couple of spares.

[ndevans]

To eliminate any confusion and to ensure that the rear hub bearing has the correct lateral loading between hub and half-shaft the thickness of the hub gasket which determines the amount of loading should be correct .
It cannot be assumed that the gasket supplied is the right thickness.
Too thin and the half-shaft flange is overloaded and too thick there is the possibility of the bearing moving in the hub.
Whilst the workshop manual gives the clearance it is not clear on how to go about determining the correct thickness of gasket required.

So to get the gasket thickness right...…………..

References:

a. BMC workshop manual AKD530L

b. Gasket part No: GFG110

c. Clearance 0.001" to 0.004". Median 0.002"

d. Bearing part No: GHB130..... Numbers stamped on outer race 40-M97. Numbers stamped on inner race40-N97. Manufacturer R+M England.

1. The bearing should be fitted fully home in the hub after fitting the lip seal. Ensure that the seal is the right way round.

2. A straight edge is placed across the outer face of the bearing and the clearance between the straight edge and hub outer face measured with a set of feeler gauges.

3. The feeler gauge measurement then has the median (0.002") subtracted from it and the resulting figure is the thickness of the gasket required.

4. Fit the correct thickness gasket to the hub, place the straight edge across the outer face of the bearing and measure the clearance between the straight edge and gasket. The clearance should now be the median 0.002".

Notes:

Determining the gasket thickness is easier with the hub off the axle.

Suitable gasket papers of various thicknesses are available from 'e' bay. https://www.ebay.co.uk/itm/GASKET-PAPER ... SwNJpbftXw
It is easy to cut a new hub gasket from a blank sheet of gasket paper when the wheel studs are removed. Use a small ball pane hammer for cutting/forming the gasket.

The gaskets supplied by the various Minor parts suppliers are not all of the same thickness so a selection of gaskets from different suppliers may prove beneficial.

Photos of the procedure to follow.

Phil

Hi Phil,

I'm looking on the R+M bearings website, and I can't find a GHB130. Am I looking in the right place?

https://www.rmbearings.co.uk/bearings/

Cheers N