Gearbox

David Watson · Post by **David Watson** » Sat Mar 31, 2012 10:46 am

Hi could anyone one help me please i have a 1958 G2 and if i go past 40/45 it jumps out of top gear do you know what the fault could be and where to get the parts

Thanks David

John Jarrett · Post by **John Jarrett** » Sat Mar 31, 2012 12:31 pm

Refer to page 51 of the workshop manual which is listed at the bottom of the link http://archives.jampot.dk/Book/Workshop_manuals/ This describes the reasons for this common fault on the early 250 gearbox and the remedy. I can't help with the parts themselves or even how to identify the modified parts.. others may be able to. Suggest you check with the club spares scheme for the replacement parts.

David Watson · Post by **David Watson** » Sat Mar 31, 2012 1:10 pm

thank you will look

ajscomboman · Post by **ajscomboman** » Sat Mar 31, 2012 5:50 pm

No spare parts for this problem at the clubs parts service. The earlier gearboxes has third and fourth gear engage with the drive pins which were prone to jumping out under load. The remedy was replacement gears with undercut dogs as a method of engagement. You'll probably be better off contacting AMC Classic Spares to see if Steven has any gears in his secondhand stock.

John Jarrett · Post by **John Jarrett** » Sat Mar 31, 2012 6:40 pm

I presume by pins, that you mean that the early 3rd gear on the mainshaft engaged in holes drilled in the 4th gear and that the later 4th gear has external dogs?

ajscomboman · Post by **ajscomboman** » Sat Mar 31, 2012 9:47 pm

Yep, thats correct, later 3rd and sleeve(4th) gear have undercut dogs.