classic motorcycle forum

Motorcycle Discussions => Identify these bikes! => Topic started by: jrlandau on March 31, 2013, 05:57:07 AM

Title: Identify a gearbox?
Post by: jrlandau on March 31, 2013, 05:57:07 AM

Can anyone help me identify this gearbox?  I'm pretty sure it's British because my Whitworth wrenches fit the case nuts, and the threads are 5/16 x 26tpi. 

Title: Re: Identify a gearbox?
Post by: wetdog on March 31, 2013, 09:51:11 AM

Norton Dolls Head i think , and the top lugs arnt damaged , last one i saw sold fetched £450 , not sure of the exact year but someone here will know . look here for more info
http://www.wdnorton.nl/Gearbox%20and%20Transmission.htm

Title: Re: Identify a gearbox?
Post by: Norton55 on March 31, 2013, 02:54:04 PM

Yes, It looks like it's a Norton Dolls head gearbox. They were used from about 1934 to 1945. The gear ratio on the gearbox 1, 1.1, 1.33, 2.33 matches that used on the Norton International's with kick start. But the gearboxes used on the Norton would have used the the top outer cover with the Norton logo, and your gearbox was probably supplied to another motorcycle manufacturer. It could be from a Brough Superior as they used Norton Dolls head gearboxes in the late 1930's.