7 replies to this topic

[AndyMiniMad.]

Hello folks!!!
This is the gearbox case from my 1380. Its been worn by the idler gear shim. Its not bad about 3/4 thou. Took it to a local machine shop today and asked them if they could weld it up to raise the worn section and then machine it flat again. They recommended simply machineing the whole thing down 5 thou and useing a fatter shim to take up the idler gear slack.
What do you think??

Edited by AndyMiniMad., 08 February 2011 - 05:59 PM.

[Guess-Works.com]

the latter...

I'd also found out why it wore the case.... so either failed idler bearing or improperly shimmed.

ps... if you hadn't already noticed you have the economy input gear on your gearbox...

Edited by Guess-Works.com, 08 February 2011 - 06:37 PM.

[MRA]

We manufacture idler shims to any size

[mini-geek]

when they say machine the whole thing down, do they really just mean the area around the idler gear bush? Because surely doing the whole thing will mean the box wont line up with the block properly...

[AndyMiniMad.]

Thanks for that. Im fairly sure the bearing in the flywheel housing is kaput. How can you tell its an economy gear and what diference will it make. Do the drop gears all have to be matched up? I could have fitted the wrong input gear by mistake. Is it important?

MRA-MINIS. I will defo need to get some new shims once this box has been machined. Thanks.

[AndyMiniMad.]

when they say machine the whole thing down, do they really just mean the area around the idler gear bush? Because surely doing the whole thing will mean the box wont line up with the block properly...

Yes sorry your correct.. just the bit thats worn will get machined down.

[Guess-Works.com]

Nothing wrong with having the eco' input, just means the gearbox will have a slight 'over drive' as the transfer gears will not be a 1:1 ratio... you may also have the eco' primary ( look for a grove through the primary gear teeth ), if you do then you'll be running 0.933:1 drop gear ratio, therefore turning a 3.4 final drive into something like a 3.1

PS, you can tell it's the eco' ( 28 tooth ) version by the grove round the shank of the gear.

[AndyMiniMad.]

Thanks Guessworks, I am useing a 3.1 final drive ratio so what sort of "real" final drive ratio will these eco gears be providing. Maybe as low as 2.9??