BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: Mike Farmer on 01 Feb, 2022, 15:39

Title: A50/65 Fork Oil Seals
Post by: Mike Farmer on 01 Feb, 2022, 15:39
 :) :) :) :)

Hi, I am looking for fork oil seals for A65. They are listed as 29-5313  and 65-5451. I cant see the difference because the foto is not the best.. Help please are they interchangeable. I assume my forks are original late 62 early 63.

Your assistance appreciated.

Mike 8) 8) 8) 8)

Title: Re: A50/65 Fork Oil Seals
Post by: Spaceman on 01 Feb, 2022, 16:21
The 1964 parts book, in particular, shows both part numbers for the same seal. All I can think of was that, at the time, there was a difference between the earlier seal design and the later one adopted in ~1964 but clearly both will fit.
Title: Re: A50/65 Fork Oil Seals
Post by: JulianS on 01 Feb, 2022, 17:51
The 1960 on A10 parts book also shows the 2 numbers.

65 5451 is marked with an asterisk and the key shows "American type"

By the time of the 1964/65 A65 sports model parts book only 65 5451 is listed.

What the difference was I dont know but I expect which ever number you use you will get the same part
Title: Re: A50/65 Fork Oil Seals
Post by: Spaceman on 01 Feb, 2022, 19:57
It looks as though the 1960-62 A10's came with either a US (29-5310) or a non-US (42-5315) oil seal holder with the two different oil seals to match. However, up to ~ 1965, the A65 was only fitted with the US oil seal holder (42-5315). I therefore now think that the two seals were of slightly different thickness and the shims indicated in the parts book were needed to be used to accommodate the difference when used with seal holder 42-5315 on the A65.

I am sure only one thickness of seal is now available and the safest approach would be to check its thickness against the old seal.

Title: Re: A50/65 Fork Oil Seals
Post by: Mike Farmer on 01 Feb, 2022, 20:19
 :) :) :) :)

Hi all thank you for your input. I thought it would be along those lines. So now I can go ahead.

Mike 8) 8) 8)