Rear hub gasket

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philthehill
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Rear hub gasket

Post by philthehill »

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
Last edited by philthehill on Sun Sep 29, 2019 10:15 am, edited 1 time in total.

RobThomas
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Re: Rear hub gasket

Post by RobThomas »

Use a small ball pain hammer
:oops:

I think I know what you mean, Phil. :D
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don58van
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Re: Rear hub gasket

Post by don58van »

Dangerous things, those hammers! :o
philthehill
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Re: Rear hub gasket

Post by philthehill »

It was a pain writing the post as just as I was about to submit the power went off and I lost everything :-?

The hammers are described as ball pane, ball pein or ball peen so a right pain to describe. I have amended the above to read ball pane. Anyway you know what I mean.

Phil

pgp001
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Re: Rear hub gasket

Post by pgp001 »

Phil

When I did mine I found all sorts of burrs and chisel marks etc where previous people had pried the flanges apart on the hub and halfshaft.
I spent quite a bit of time with a very fine file ensuring the mating faces were nice and flat, and any holes were very slightly countersunk to remove any raised edges before starting the hub rebuild and taking any measurements for the gasket.

Glad you are doing an instruction page for this, it does seem to crop up fairly often. :D

Phil
ampwhu
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Re: Rear hub gasket

Post by ampwhu »

Rear Hub.JPG
Rear Hub.JPG (93.08 KiB) Viewed 4191 times
this is taken from my A30 manual (identical to my Series 2).

Around 10 years ago, I replaced a hub on the A30 for a later one with the rubber seal. I decided then to make my own half shaft seals out of some thin cork sheet as I was fed up with it leaking after replacing numerous times in the past. At the same time, I fitted stronger halfshafts as I fitted larger engines and better gearboxes etc. I still have this cork sheet and have now fitted my own "gaskets" to all 3 cars without any leakages.

whilst i can sort of see the need for a correct thickness of gasket, problems will arise if the gasket is too thin. In this case, ive noticed that plenty of people have fitted 2 and sometimes 3 gaskets to each half shaft to cure leaks onto their brakes. Of course this would be irrelevent if the vent hole in the backplate is full of debris.
philthehill
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Re: Rear hub gasket

Post by philthehill »

Whilst you may not have experienced any leaks using a cork gasket it is totally the wrong material for use in this application. Cork sheet is squashable and so will not give the correct side load on the bearing but cork gasket material will certainly fill any imperfections between half-shaft and hub.

I personally would not recommend its use in this application.

The need to use more than one gasket may be the result of not having the right thickness gasket paper and not necessarily to cure an oil leak.
Having read the attached extract from the A30 workshop manual it produces the same problem as the Minor workshop manual in that whilst the A30 manual gives a minimum thickness of paper gasket it does not go about telling you how to achieve the correct lateral loading on the hub bearing which leads me back to the prognosis above how do you get the right lateral preloading on the hub bearing with a squashable cork gasket?
At least the Minor workshop manual gives the correct clearance between the half shaft flange and the paper gasket/hub flange which when the half-shaft is fitted and wheel nuts tightened will give the right lateral loading on the hub bearing.
Later A30/A35 workshop manual may have the same details/specifications as the later Minor workshop manuals given that the axles are near identical.
Quite a few details/specifications that were not included in earlier workshop manuals were included in later editions.

The later hubs with the rubber 'O' ring are an improvement on the earlier hubs and should be retro fitted if possible.

As important if not more than the drain in the brake backplate is the main axle vent/breather located on the main axle casing which should be kept clear to allow any pressure that builds up inside the axle casing due to the agitation of the axle oil to escape.
The drain in the brake backplate only comes into play if the hub oil seal has failed it is not there to allow breathing of the hub or drain oil away from the half-shaft flange gasket.

Phil

ampwhu
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Re: Rear hub gasket

Post by ampwhu »

the Austin A40 manual from 1971 states almost the exact same.
philthehill
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Re: Rear hub gasket

Post by philthehill »

Whilst that may be true it still does not address the required lateral loading on the hub bearing.

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ndevans
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Re: Rear hub gasket

Post by ndevans »

Thanks Phil, very instructive!
cheers N

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33063, Eridge, Sept 2021 by Neil Evans, on Flickr
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ndevans
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Re: Rear hub gasket

Post by ndevans »

Seems like the most appropriate thread to post this.

Having got the bearings back in the hub, secured with a bit of bearing lock, I've now got the hub back on the axle casing. The BMC manual is a little vague on this subject, however, and I'm not sure how far in the hub should go.
I started by tapping the centre race of the bearing gently, using a large socket as a drift. Once there was enough thread showing, I put on the hub nut, and screwed it home using my home made hub spanner.
So how far should the hub go? I've screwed the hub nut so that the locating hole in the thread is fully visible (this is what the locating tab in the lock washer fits into). There's probably another 1/4-1/2 turn of the nut possible-do I need to wind it on as far as I can go? I know there is no torque setting for it.

Photo below-the locating hole is on the left, not visible in the photo, but it is fully exposed.

Cheers Nick
IMG_20191014_230817~2.jpg
IMG_20191014_230817~2.jpg (408.94 KiB) Viewed 4026 times
cheers N

Image
33063, Eridge, Sept 2021 by Neil Evans, on Flickr
'69 Traveller, 1275, discs.
philthehill
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Re: Rear hub gasket

Post by philthehill »

There are two things to consider:-

1. That the bearing is fully home in the hub.

2. That the bearing is fully home on the axle tube.

The hub/bearing assy should be installed on the axle tube and the nut fitted and done up fully tight (or as far as it can go) before removing the nut and fitting the lock washer. The nut should be re-fitted and done up fully tight. Doing it that way ensures that the bearing is fully home on the axle tube and ensures that the lock washer is not damaged.

All you can do is fully tighten the hub nut. There is no other option in ensuring the bearing is fully home on the axle tube.

When you fitted the bearing into the hub with bearing lock - did you press the bearing fully into the hub and kept the press load on the bearing until the bearing lock had cured?
Last edited by philthehill on Tue Oct 15, 2019 8:14 am, edited 1 time in total.

pgp001
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Re: Rear hub gasket

Post by pgp001 »

You need to nip it up so the bearing inner race is good and tight against the shoulder on the axle tube.

Phil

T' Other Phil beat me to it.
smithskids
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Re: Rear hub gasket

Post by smithskids »

I assume you don't fit the gasket as well as the "O" ring or the hub loading would be incorrect.
pgp001
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Re: Rear hub gasket

Post by pgp001 »

Yes both gasket and O ring are normally fitted, not sure what you mean about the hub loading though.

Phil
philthehill
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Re: Rear hub gasket

Post by philthehill »

The hub loading is the nip of the bearing between hub and half-shaft.
The thickness of the gasket paper determines the nip.
If the right thickness of gasket is not fitted it can effect the hub & bearing in that the half-shaft flange can be put under strain and the hub can float.

philthehill
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Post by philthehill »

See my original post above.

smithskids
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Re: Rear hub gasket

Post by smithskids »

Yes, see what you mean Phil, pensioneritus creeping in!!
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ndevans
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Re: Rear hub gasket

Post by ndevans »

philthehill wrote: Tue Oct 15, 2019 8:10 am There are two things to consider:-

1. That the bearing is fully home in the hub.

2. That the bearing is fully home on the axle tube.

The hub/bearing assy should be installed on the axle tube and the nut fitted and done up fully tight (or as far as it can go) before removing the nut and fitting the lock washer. The nut should be re-fitted and done up fully tight. Doing it that way ensures that the bearing is fully home on the axle tube and ensures that the lock washer is not damaged.

All you can do is fully tighten the hub nut. There is no other option in ensuring the bearing is fully home on the axle tube.

When you fitted the bearing into the hub with bearing lock - did you press the bearing fully into the hub and kept the press load on the bearing until the bearing lock had cured?
Thanks for that Phil. That's pretty much how I've done it-nut first, then washer.

Regarding the bearings- I put the bearings in the freezer overnight, then warmed the hubs up in the oven until they were just hot enough to hold. The bearings then just dropped straight into the hub, all the way, with an audible click, with bearing lock smeared inside the hub. I've checked it with a dial indicator, the bearing is just proud of the gasket, by about 0.1mm.
cheers N

Image
33063, Eridge, Sept 2021 by Neil Evans, on Flickr
'69 Traveller, 1275, discs.
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ndevans
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Re: Rear hub gasket

Post by ndevans »

philthehill wrote: Sun Sep 29, 2019 9:30 am 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
Reviving an old thread here. I fitted new bearings, seals, O rings and paper gaskets a year or so back, and I now need to renew the gaskets, because I've had the half shaft out and the gasket off, to inspect the bearing. As a result the gasket is damaged, and needs renewing, so I need to get the right thickness gasket.
Just to be clear, in step 2 above :-

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.

Do you mean the outer face of the bearing should be a little proud of the hub?

Also, is it ok to use 2 or more gaskets, if necessary, to achieve the correct thickness?

Cheers N
cheers N

Image
33063, Eridge, Sept 2021 by Neil Evans, on Flickr
'69 Traveller, 1275, discs.
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