BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: LIONELSMITH on 11 June, 2017, 20:24:40

Title: Needle bearings
Post by: LIONELSMITH on 11 June, 2017, 20:24:40
I have converted my STD gearbox on my 1961 A10 to needle rollers. As the needle roller has no thrust washer portion that the bush has, there is nothing to hold it in place. Should I arrange to have a groove machined for a spring washer?
Title: Re: Needle bearings
Post by: JulianS on 12 June, 2017, 09:27:45

You need to use the proper hardened steel thrust washers at either end of the layshaft;

Between inner cover and H gear part 42 3079 (also used on A65) which is listed as 0.113 - 0.115 inch thick, also available thicker as 42  3212 (0.120 - 0.122 inch thick) and 42 3213 (0.127 - 0.129 inch thick)

Washers from my box shown left to right in photo.

Between H gear and layshaft shoulder - same thrust washer as bushed box part 67  3203.

Between B gear and maincase clutch side part 42 3078.

I would not use a spring washer which would probably break up.