The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: Russ on 28.07. 2013 08:41

Title: Sliding plate behind clutch
Post by: Russ on 28.07. 2013 08:41

Guys I apologise for this question in advance.
I have been reading your posts regarding the sliding plate behind the clutch and my question is -  should my 51 A10 Gold Flash have one?
Russ

Title: Re: Sliding plate behind clutch
Post by: Brian on 28.07. 2013 09:19

No.

Title: Re: Sliding plate behind clutch
Post by: muskrat on 28.07. 2013 09:38

G'day Russ. Your g/box is fixed to the motor, the inner primary has a small sealed hole for the mainshaft. The swing arms gearbox moves so needs a bigger hole and the sliding plate seals it.
Cheers

Title: Re: Sliding plate behind clutch
Post by: Russ on 28.07. 2013 10:09

Thanks Muskrat & Brian,
I thought they were fitted to the Swing-arms and now I know why.
Russ

Title: Re: Sliding plate behind clutch
Post by: trevinoz on 28.07. 2013 22:37

Russ,
               There should be two plates riveted to your chaincase, one each side, with some sort of fibrous seal sandwiched in.
Drill out the rivets and fit a modern lip seal and rivet the plates back on.

Trev.

Title: Re: Sliding plate behind clutch
Post by: Russ on 29.07. 2013 06:45

Trev
Yes I have the 2 plates and seal in a set of crankcases which don't look too good. Can you elaborate on what a new modern Lip Seal is and what type of riverts would I need for this application.
Russ

Title: Re: Sliding plate behind clutch
Post by: Greybeard on 29.07. 2013 08:33

I got a seal from Draganfly and not trusting my riveting skills used small screws with Nylock nuts. Warning: there is not much room between the clutch bearing sleeve and the seal so the screw heads need to go on the clutch side. The chaincase is weak around the rivet holes, (DAMHIK) so be careful!

Title: Re: Sliding plate behind clutch
Post by: trevinoz on 30.07. 2013 22:44

Russ,
           I don't know the part number for the seal, I'll check the shed to see if I have one on the shelf.
Just measure the shaft diameter, the housing diameter and thickness and see your friendly bearing bloke.
I used pop rivets to reassemble. I don't think that they will leak but if you are worried about leakage try to find blind rivets. Probably not worth the effort for three, though. A dab of silicon should do the trick.

Trev.

Title: Re: Sliding plate behind clutch
Post by: Brian on 31.07. 2013 00:08

If memory serves me correctly which it most likely doesnt, I think the shaft is 3/4" so 19mm for the inner diameter and the outer is either 32 or 35mm.   

Title: Re: Sliding plate behind clutch
Post by: trevinoz on 01.08. 2013 00:10

Russ,
              The seal which I use is marked :- NOK  391-2883-048
It measures 3/4" x 1 3/8" x 5/16"

Trev.

Title: Re: Sliding plate behind clutch
Post by: Russ on 01.08. 2013 03:30

Thanks Trev I'll chase it up.
Russ.