Changing diff ratio without splitting engine/box

Post any technical questions or queries here.
Post Reply
User avatar
AndyB72
1275 Cooper S
Posts: 1386
Joined: Thu Jun 24, 2010 12:44 pm
Location: Wakefield, West Yorks
Been thanked: 1 time

Changing diff ratio without splitting engine/box

Post by AndyB72 »

Is there a way of locking the gearbox to change the diff ratio without splitting the engine/gearbox?
User avatar
Spider
1275 Cooper S
Posts: 4861
Joined: Mon May 07, 2012 6:10 am
Location: Big Red, Australia
Has thanked: 206 times
Been thanked: 79 times

Re: Changing diff ratio without splitting engine/box

Post by Spider »

Gosh yes, why make work when you don't need to!

Remove the diff outputs (flanges, yokes or pot joints), remove the diff side plates, remove the diff cap and there's the Crown Wheel, change that over.

Remove the Speedo Drive End Housing, lock in 1st and 4th (all synchro) or 2nd and 4th (3 Synchro) depending on the type of gearbox, undo Pinion nut, remove Pinion, refit, and basically the reverse of the above.

Regasket, reseal, re-shim the diff, all on a sasame seed bun ;)
User avatar
rich@minispares.com
1275 Cooper S
Posts: 6806
Joined: Thu Aug 08, 2013 3:16 pm
Been thanked: 2 times

Re: Changing diff ratio without splitting engine/box

Post by rich@minispares.com »

you can do it but its an utter git to lock a rod change into 1st and 4th, its easy on a remote as the fork rods are accessible (but take the two detent plunger cover bolts out first to make it easier to manipulate the forks)
should you wish, you can contact me on rich@minispares.com

'long beard boss'
User avatar
Spider
1275 Cooper S
Posts: 4861
Joined: Mon May 07, 2012 6:10 am
Location: Big Red, Australia
Has thanked: 206 times
Been thanked: 79 times

Re: Changing diff ratio without splitting engine/box

Post by Spider »

rich@minispares.com wrote:you can do it but its an utter git to lock a rod change into 1st and 4th
Mmmm,,, rubbish. It's easy enough, though fair enough, it's easier on a remote box.
User avatar
AndyB72
1275 Cooper S
Posts: 1386
Joined: Thu Jun 24, 2010 12:44 pm
Location: Wakefield, West Yorks
Been thanked: 1 time

Re: Changing diff ratio without splitting engine/box

Post by AndyB72 »

Smart thanks! Its a remote box by the way.
User avatar
rich@minispares.com
1275 Cooper S
Posts: 6806
Joined: Thu Aug 08, 2013 3:16 pm
Been thanked: 2 times

Re: Changing diff ratio without splitting engine/box

Post by rich@minispares.com »

Spider wrote:
rich@minispares.com wrote:you can do it but its an utter git to lock a rod change into 1st and 4th
Mmmm,,, rubbish. It's easy enough, though fair enough, it's easier on a remote box.
not if you have massive hands like me it isnt :lol:

I have a bent screwdriver for hooking/pushing the 3rd/4th hub across, which does help!
should you wish, you can contact me on rich@minispares.com

'long beard boss'
mk1
Site Admin
Posts: 19835
Joined: Thu Jun 24, 2010 11:30 am
Location: Away with the Faries
Has thanked: 3 times
Been thanked: 10 times

Re: Changing diff ratio without splitting engine/box

Post by mk1 »

Image
User avatar
Spider
1275 Cooper S
Posts: 4861
Joined: Mon May 07, 2012 6:10 am
Location: Big Red, Australia
Has thanked: 206 times
Been thanked: 79 times

Re: Changing diff ratio without splitting engine/box

Post by Spider »

rich@minispares.com wrote:
I have a bent screwdriver for hooking/pushing the 3rd/4th hub across, which does help!
Yeah, that's pretty much how I do them, on the shift bell crank

Image

Push the 3rd / 4th crank IN, then lever the 1st / 2nd hub across, sometime need to rock the gears a little to get that one on.

But, that's all academic, as the OP has a remote.

and Mark
mk1 wrote:Image
I recon my fingers are at least as big as this guys ;)
Post Reply