The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: jimmy on 23.01. 2010 11:50

Title: `51 gearbox
Post by: jimmy on 23.01. 2010 11:50

G`day, the gearbox on my `51 has no oilseal on the output shaft, it has a steel plate that is a close fit to the sprocket boss, it appears to be original. Does this type leak oil, or should fit a plate with a real seal on it?
regards Jim

Title: Re: `51 gearbox
Post by: muskrat on 23.01. 2010 20:04

G'day Jimmy,
                 They do leak a bit. the original sprockets had a spiral groove in the boss to work the oil back in.
Cheers

Title: Re: `51 gearbox
Post by: trevinoz on 24.01. 2010 06:20

Jimmy,
             As Muskrat says. If your sprocket is worn out, replace it with the later type and fit an oil seal.
Trev

Title: Re: `51 gearbox
Post by: jimmy on 24.01. 2010 10:44

Thanks Muskrat and Trev, my sprocket doesn`t have the reverse scroll which tricked me,so I`ll do as you say, regards Jim

Title: Re: `51 gearbox
Post by: BSA_54A10 on 24.01. 2010 11:54

The 2 different sprockets are also different sizes, the latter oil seal type being slightly bigger than the early oil slinger type so you will know if it is wrong as the sprocket will be too tight in the box