Ausmini
It is currently Wed Jun 25, 2025 9:34 pm

All times are UTC + 10 hours




Post new topic Reply to topic  [ 7 posts ] 
Author Message
 Post subject: Gearbox questions
PostPosted: Sun Jun 23, 2024 8:40 am 
Offline
848cc
848cc
User avatar

Joined: Fri Aug 06, 2004 5:47 pm
Posts: 150
Location: Victoria
Greetings all. It's been a while since I posted here but I now have a new potential project or two in mind and would appreciate some thoughts from the Brains Trust if possible.

The basic question is this: can a 4 synchro set of gears be installed in (a) a magic wand (850) gearbox and/or (b) a remote change (Morris 1100) gearbox?

Plan (a) is to update an 850 project to all synchro without losing the iconic magic wand. The secondary plan (b) is to improve my original M1100 3 synchro to 4 synchro, also without external changes.

I'm aware that there are major differences between early and late boxes, particularly in the selection system, so I imagine any donor set would need to be compatible. Sort of rules out rod change internals I suppose, or does it?

I've built a few gearboxes in my time (not just Minis) so I have the skills to do this, just not the first hand experience of Mini boxes other than the rod change iteration.

So if any Experts out there have done this, I'd love to hear from you. Or, if it's just not feasible, I guess I want to hear that too.

Thanks in anticipation, Pottsy.

_________________
Smile Up at The Trucks!


Top
 Profile  
 
 Post subject: Re: Gearbox questions
PostPosted: Sun Jun 23, 2024 9:01 am 
Offline
religious status
religious status
User avatar

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 39752
Location: near Baulkham Hills, NSW
Short answer is no.
You need a 4 synchro case. You can then fit the 850 or Morris 1100 diff housing and shifter. After checking bearing housings for diameter and alignment.
Leave the 2 dowels out if you have to. I've done quite a few.
You can fit all the rod change gearset except for reverse gear into a 4 synchro remote case.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. :mrgreen:


Top
 Profile  
 
 Post subject: Re: Gearbox questions
PostPosted: Sun Jun 23, 2024 9:23 am 
Offline
998cc
998cc
User avatar

Joined: Fri May 03, 2019 7:17 am
Posts: 750
I seem to remember there was a magic wand shifter that fitted a 4 syncro box.

_________________
Cheers Dave.


Top
 Profile  
 
 Post subject: Re: Gearbox questions
PostPosted: Sun Jun 23, 2024 10:03 am 
Offline
848cc
848cc
User avatar

Joined: Fri Aug 06, 2004 5:47 pm
Posts: 150
Location: Victoria
Thanks Doc.

I've always considered the casing and the diff housing to be a matched set. Are you saying that a magic wand diff housing will bolt up to a 4 synch casing? If they're mismatched then I guess you're saying they need to be tunnel bored to suit the bearings?

Obviously the lateral clearances need to be set and shimmed, easy enough. Also, can I assume the mesh clearance of the cw/p would be pretty much the same between diff housings? Once again, easy enough to check I guess.

I'm encouraged now! Cheers, Pottsy.

_________________
Smile Up at The Trucks!


Top
 Profile  
 
 Post subject: Re: Gearbox questions
PostPosted: Sun Jun 23, 2024 10:29 am 
Offline
1275cc
1275cc
User avatar

Joined: Sun Apr 29, 2012 1:19 pm
Posts: 4494
Location: Wollongong, NSW
I was lucky enough that my 850 diff cover fit perfectly on a 4 synchro remote casing, no machining needed

Image

_________________
Image


Top
 Profile  
 
 Post subject: Re: Gearbox questions
PostPosted: Sun Jun 23, 2024 10:37 am 
Offline
religious status
religious status
User avatar

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 39752
Location: near Baulkham Hills, NSW
Pottsy wrote:
Thanks Doc.

I've always considered the casing and the diff housing to be a matched set. Are you saying that a magic wand diff housing will bolt up to a 4 synch casing? If they're mismatched then I guess you're saying they need to be tunnel bored to suit the bearings?

Obviously the lateral clearances need to be set and shimmed, easy enough. Also, can I assume the mesh clearance of the cw/p would be pretty much the same between diff housings? Once again, easy enough to check I guess.

I'm encouraged now! Cheers, Pottsy.


Laterally they are the same. Vertically not a problem, drill the stud holes if you have to. You could tunnel bore them if you have the equipment, but I measure how much needs to come off each particular corner of the diff housing to get both bearing bores the same, then set that up on the mill and skim it flat.
Only had to do that on one diff cover.
You can assemble with 1 gasket, 2, or none depending on the measurements.
Crown wheel mesh is determined by the gearbox case, diff housing just holds the bearing in.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. :mrgreen:


Top
 Profile  
 
 Post subject: Re: Gearbox questions
PostPosted: Sun Jun 23, 2024 10:42 am 
Offline
religious status
religious status
User avatar

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 39752
Location: near Baulkham Hills, NSW
Steam wrote:
I seem to remember there was a magic wand shifter that fitted a 4 syncro box.


Yes it's the puddin' stirrer shifter. Bolts on where a remote extension would. But it was rubbish design compared to the 850 set-up. A ball sitting in a bit of tin with no adjustment.
Agricultural solution. And all NLA now.

Was used on pov pack clubby. And some Mokes maybe?

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. :mrgreen:


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 7 posts ] 

All times are UTC + 10 hours


Who is online

Users browsing this forum: stewartp and 101 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  

© 2016 Ausmini. All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.