BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: Phil C on 19 Feb, 2021, 17:56

Title: Clutch oil seal (1965 B40F)
Post by: Phil C on 19 Feb, 2021, 17:56
Hello all,  Looking for the source of a slight oil leak, I've just removed the circular plate which lives behind the clutch. Keen to have a look at the oil seal, I was interested to see that there appears to be a bit of damage to it. I was surprised because I fitted it a couple of years or so ago and the bike has done very little mileage since then (probably not relevant.) I don't know much about oil seals, but it looks to me (see pics) like the actual sealing lip is fine, but the other side (gearbox side) is damaged. Is that significant?  How could it have happened? I've got a replacement to put in, but would be interested to know how it might have happened and if it's significant.

You'll also see marks on the taper and (bush?) Running my finger nail across these, I don't feel any very obvious wear/depression, maybe a slight grooving on the taper. Hopefully the marks are not a concern?

Any thoughts/observations/advice would be much appreciated.

Phil.
Title: Re: Clutch oil seal (1965 B40F)
Post by: Blackthou on 19 Feb, 2021, 21:49
Just a question, is the oil seal the wrong way round?
Title: Re: Clutch oil seal (1965 B40F)
Post by: Phil C on 19 Feb, 2021, 21:58
Anybody know? (see photos)
Title: Re: Clutch oil seal (1965 B40F)
Post by: PeteRae on 19 Feb, 2021, 22:57
Reckon its the right way round Phil...its purpose is to stop, or slow down, the oil escaping from the primary case. Did you have the big fluffy washer fitted between the sprocket nut and the plate? It soaks up some of the oil but might also keep rubbish off the seal face. You'll get all sorts of road rubbish flung around the sprocket that could do that kind of damage!
Pete.
Title: Re: Clutch oil seal (1965 B40F)
Post by: Phil C on 19 Feb, 2021, 23:11
I'm sure I would have checked when I fitted it that it was the right way round.

Yes I had a felt washer behind the plate.

Thanks.      Phil
Title: Re: Clutch oil seal (1965 B40F)
Post by: Phil C on 20 Feb, 2021, 07:25
Quote from: Phil C on 19 Feb, 2021, 23:11
I'm sure I would have checked when I fitted it that it was the right way round.
Or of course I might have just made sure I fitted it the same way as the previous one had been. Just checked Rupert Ratio and Haynes and service sheets: can't find any indication of which way is right.   Phil
Title: Re: Clutch oil seal (1965 B40F)
Post by: Pete A10 on 20 Feb, 2021, 09:10
Oil seals are normally fitted with the lip facing the side where you want to retain the oil
Title: Re: Clutch oil seal (1965 B40F)
Post by: Phil C on 20 Feb, 2021, 09:11
Does it look the right way round on the photos?
Title: Re: Clutch oil seal (1965 B40F)
Post by: PeteRae on 20 Feb, 2021, 09:27
yup....the lip/open side is facing the clutch.
If you put it in the other way it will  try to fold in when you push it over the shaft.
Pete
Title: Re: Clutch oil seal (1965 B40F)
Post by: Phil C on 20 Feb, 2021, 09:30
Thanks Pete.   Phil
Title: Re: Clutch oil seal (1965 B40F)
Post by: Phil C on 20 Feb, 2021, 15:22
Yes, just come across it in RR, p.101.  Phil
Title: Re: Clutch oil seal (1965 B40F)
Post by: Blackthou on 20 Feb, 2021, 21:52
Sorry for any confusion, just asking a question in case.
Title: Re: Clutch oil seal (1965 B40F)
Post by: Phil C on 21 Feb, 2021, 09:04
Worth checking, thanks Rick.  Phil
Title: Re: Clutch oil seal (1965 B40F)
Post by: PeteRae on 21 Feb, 2021, 10:26
Its easy to put it in the wrong way guys.....holds hands up :-[
Pete