Rear axle oil seals

[MichaelElsom]

I am amzed to find that this is the first post since January, but here goes...
As long ago as 2018 I had noticed an obvious oil leak from the os rear brake drum - manifested by tell oil strakes on the inside face of the tyre. The car was then sat in the garage until I was able to get round to dealing with its various problems until early 2023 (combination of COVID and personal health problems).
I changed the oil seal and used one of the recently made new retaining rings which James kindly let me have.
Since then I have covered approximately 1,500 miles with no apparent problems in this department. The first time the car went anywhere this year was a round trip of 50 miles or so on New Year's Day. Nothing untoward appeared then as far as I could see.
I was therefore surprised to see what looked like a trace of something coming down the inside face of the tyre towards the end of February. Over optimisim saw this dismissed as dirty water from the last wash so off I went in the car to a motoring friend's funeral not very far away.
There was nothing further to be seen after that trip and so at the beginning of April I did a 60 mile round trip and when I checked the car the next morning, there was a much more obvious line of oil down the inside face of the tyre. Stripping things down the other day revealed oil in the brake drum which had obviously been coming through the axle bearing and then finding its way into the brake drum before dripping onto the wheel rim and then running down the tyre. There is no sign of this happening except when the car is stationary - the previous leak had resulted in liberal radial leaks onto the brake drum, wheel spokes, rim and tyre.
Examination of the seal fitted in 2023 reveals no obvious defects. Needless to say when dismantling the two dished washers fell out and so I could not record which way they had been fitted!
I seem to remember some wisdom about seals and bearings on this forum or in the Newsletter which might have helped, but so far I have failed to find it.
Can anyone offer any ideas as to why this leak should have occurred, how to remedy it and - in particular - which way round the washers should go!       
The other odd things is that despite carefully cleaning all the oil out of the wheel bearing carrier, oil still appears in the threads - have I over-filled the axle?

[Mark Dibben]

Hello Michael,
Speak to Tristan at Omicron. They have just completely re-done the rear diff seals on SN7801, which had lips, but the seals on each were not only different from each other, but both were the wrong size! 
All best cheers,
Mark

[Kari]

Hi Mark,

I wrote about 2 different types of rear brake drums in the Augusta Newsletter No 30. There, the brake drums required different size seals of the modern variant (lip seals). The dished washers (Belleville washers) are spring washers compressing the inner race of the ball bearing.
Karl

[MichaelElsom]

Dear Karl
Thanks for this wisdom.
Just to confirm everyone's (probable!) view that I am an idiot, I cannot work out from the image which way round the washers should go!
Reading what you say it sounds as though the dished (concave) face should lie against the bearing face thus bearing more on the bearing race which is in contact with the axle shaft and thus rotating with the axle shaft.
Could you be good enough to confirm whether that is right or not.
Incidentally there would appear to be two different types of axle - the one shown in the spares list is quite different to CLM (a 1936 car). The housing that holds the bearing is held in place by a ring of machine screws which go through the backplate and are secured by nuts.   
Michael

[MichaelElsom]

I have managed to find the answer to the question about the washers by looking again at Dale Hick'sdrawing in Newsletter 10b.

[Kari]

Dale Hick's drawing is far better than mine!
The very early Augusta had a different rear axle. In my catalogue the later one is pictured. It may well be that the early axle had different attachment if the wheel bearings and hub.
See Augusta Newsletter No 30

If there is any dripping from the drain behind the back plate, the drain can be extended by short length of hose, to avoid oil dripping onto the tyre.

Karl

[higgsy 45]

Hi Michael   My memory doesn't remind me to look on the forum very often, it's obviously been a long time.  I had to do a lot of rectification when I got my Augusta, including front and rear brakes and seals.  I did a drawing of what I did to my car plus other drawings, so not sure if I sent DH/LA 21113/SK1 to Morris.
I basically wanted to remove any future risk of oily brakes (until I had to buy 4 new cylinders)
The car had been fitted with Aramid packings (good for 20,000psi pumps but not back axles) so  they had worn serious grooves in the sealing face of the half shafts, I didn't have a parts book at the time so I didn't know that there is a ring which could be machined off and a new one fitted with the correct sealing diameter retained. I had mine machined down to 35.00 diameter (originally 38.00).
I bought a 35 x 52 x 7 standard lip seal which sits in the axle recess nicely but not push/light press fit, I used the original spring which pushed the seal face to the housing and gave a seal, I then bought a 4602-2RS sealed double row ball bearing which is 30 x 62 x 20 long (1mm longer than original) and reassembled it with my 2 very basic retaining nuts which still live there, these do not have a recess for an internal oil seal.
All good so far!
This might come in useful for someone.
Cheers
Dale