ausmini
https://www.ausmini.com/forums/

Gearbox woes
https://www.ausmini.com/forums/viewtopic.php?f=2&t=76036		 Page 1 of 1
Author:  looopy [ Tue Mar 20, 2012 9:29 am ]
Post subject:  Gearbox woes
I have my Cooper S back home in NZ, the original engine is out & has been looked over by a mechanic.

The gearbox has close ratio straight cut gears which apprantly are well beyond their used by date.
I would like to make an original gearbox to go with a pretty original engine as I engine I have in the car is a 1410 with a new straight cut box in it. This then gives me options

What are peoples idea on what to do and more importantly were to go
for parts.
Do I replace the gears with a std set or just look for a Mk2 S gearbox somewhere ?

Thoughts???
Author:  Irish Yobbo [ Tue Mar 20, 2012 10:02 am ]
Post subject: 
Quote:
The gearbox has close ratio straight cut gears which apprantly are well beyond their used by date.


I'm no expert, but it's very hard to tell the wear of the gears without stripping the box down. The laygear (the big expensive one) should be good as new unless something catastrophic has happened, like teeth breaking off or something. The other gears don't tend to wear either unless the synchros or forks are very worn, which can wear and chip the dog teeth.

What I'm saying is that the expensive bit of the box - the straight cut close ratio gears - might be fine. It's most likely to be the relatively cheap bearings and synchros. Did your mechanic say the box was worn, or was he talking about the gears themselves?
Author:  looopy [ Tue Mar 20, 2012 10:10 am ]
Post subject: 
In typical mechanic terms he said that the SCCR gears were stuffed.

I had a lot of confidence in him (he race prepares all types of cars, used to race mini's himself and build the other engine for the previous owner)
but now I'm not so sure.

Would it be cheaper to but a Mk2 S box if I want something original or am I likely to get problems with that too?
Author:  drmini in aust [ Tue Mar 20, 2012 10:25 am ]
Post subject: 
Straight cut gears wear their teeth more than helicals do, due to point loading on the teeth.
Mk2 S box had almost the same gears in it as an Oz Mini K 1969-71 or early Oz Clubby, 1971-74.
The exceptions are the 22G1371 1st motion shaft and the 22G1040 cluster/laygear. Swap these in and fit a 3.44 diff and you have Mk2 S ratios. I run 2 of these boxes under a 1360 and a 1412 stroker.

The 22G1371 is getting a bit scarce new now, but you can replace this with a DAM3167. Same gear, except it has an 18mm needle bearing inside instead of 14mm. I can modify your standard mainshaft to suit this bearing.

Mk2 S helical gears are pretty durable for road use unless you go flat shifting. If you want to do that, go buy a Jap car... :lol:
Author:  GT mowog [ Tue Mar 20, 2012 12:44 pm ]
Post subject: 
drmini in aust wrote:
The 22G1371 is getting a bit scarce new now


Doc, I think, this was the case, but I seem to recall Mini Spares were making them again, only quite recently.
Author:  drmini in aust [ Tue Mar 20, 2012 1:27 pm ]
Post subject: 
You could be right, but not long ago nobody had any.
I prefer the DAM3167, the bigger mainshaft nose bearing is more durable.
Author:  kiwiinwgtn [ Tue Mar 20, 2012 7:58 pm ]
Post subject: 
Try Phil Deane From PD Automotive (WGTN) of Swift Automotive (CHCH)

Phil is a Mini Specalist

He should have the bits you want

PM and I will send you his details

Kiwiinwgtn
Page 1 of 1 All times are UTC + 10 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/