Creating a brand new ’50 year old’ gearbox from scratch

General Chat with an emphasis on BMC Minis & Other iconic cars of the 1960's. Includes information on MK1 Action days.
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iain1967s
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Creating a brand new ’50 year old’ gearbox from scratch

Post by iain1967s »

Another in my occasional series of articles under the general theme of ‘adventures in classic mini ownership’. I’m posting with prior permission of Mark - these were originally written by me for our local mini club newsletter, but I thought may be of wider interest here.
This one is a multi-parter, based on this thread but with technical details reduced for a more general audience.

Part 1 - “Gearing up” - from the December newsletter is attached (click to enlarge), and Part 2 will probably be run in January’s edition.
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Peter Laidler
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Re: Creating a brand new ’50 year old’ gearbox from scratch

Post by Peter Laidler »

Mark, will you do us all a favour and, if Iain agrees, at the end of this series, publish it in full (and bigger size please!) on the how-I did-it part of the tech forum. Timely too as I'm about to start sumfink similar but 4 speed all synchro. Thanks Iain and Mark

iain1967s
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Re: Creating a brand new ’50 year old’ gearbox from scratch

Post by iain1967s »

Peter, pm me your email address and I’ll send you the draft text for the complete series of articles. But bear in mind that I deliberately dumbed down the actual sequence for a more general audience.

This one is much more of a running commentary, than a technical how-to. There are some good hands-on videos on YouTube if it’s a technical guide to rebuilding that you’re looking for.

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winabbey
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Re: Creating a brand new ’50 year old’ gearbox from scratch

Post by winabbey »

In case it's of interest I have scanned a four page article from the Sept 1972 issue of Cars and Car Conversions magazine that describes with text and photos how to rebuild a 3 speed Mini gearbox. I can post on here on request.

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mk1
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Re: Creating a brand new ’50 year old’ gearbox from scratch

Post by mk1 »

Always happy to post & host this type of article.
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winabbey
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Re: Creating a brand new ’50 year old’ gearbox from scratch

Post by winabbey »

mk1 wrote:Always happy to post & host this type of article.
Below courtesy of Cars and Car Conversion magazine - September 1972 issue.

Please click on the link below to open the file.

http://mk1-performance-conversions.co.uk/pdf/3sync.pdf

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surfblue63
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Re: Creating a brand new ’50 year old’ gearbox from scratch

Post by surfblue63 »

Peter Laidler wrote:Mark, will you do us all a favour and, if Iain agrees, at the end of this series, publish it in full (and bigger size please!) …
If you place you cursor on the image and click, the image opens up. Then you can click on it again and it will enlarge to the original size. If you right click your mouse you can copy the picture to your hard drive and view at your leisure, obviously remembering where you saved it to.
Has any body seen a dog dyed dark green?

iain1967s
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Re: Creating a brand new ’50 year old’ gearbox from scratch

Post by iain1967s »

The C&CC article is very close to the sequence I used, but I will highlight two differences:

1. The A type gears did not all use bushings. Late A type gears (eg the 190 gearbox used on 1071 S) have needle rollers on the 3rd gear. I found that out the hard way - details to follow in part 2 of my article.

2. The modern reproduction laygear does not use a spacer between the inner circlip and the bearing. Instead, the laygear is now machined to use the longer needle roller bearing cages used on the 4 synchro box. Both bearings stop up against the inner circlips, so the assembly drawings in the original akd are now quite misleading.

Also, I rebuilt it with an ‘S’ Hardy Spicer diff rather than using an LSD, so that was a little more straightforward.

iain1967s
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Re: Creating a brand new ’50 year old’ gearbox from scratch

Post by iain1967s »

Part two, hot off the press...
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iain1967s
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Re: Creating a brand new ’50 year old’ gearbox from scratch

Post by iain1967s »

Third and final part of my “magnificent octopus”.
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