Ttalk Tech

insert content here

5 & 6-speed gearboxes for the TD/TF - a project in process


 I love to drive my TF. I want to be able to use the full capacity of what is now, quite a good engine, so I continue to cast about for a 5_speed gearbox. The purpose of this thread is to see if there is not some sensible alternative to the pricey kits that put a 5 or 6-speeds out of reach for many of those all over the world, that participate in this BB.


At present, the most affordable choice seems to start with the difficult (if not downright impossible)_to_find gearbox for the ‘77 to 82 Datsun 210 (note: NOT the 210B), and the Ford Sierra type 9 g/b, now again being manufactured in Germany, but I believe there are other options. Both of these are available in kit form specifically for the TD and TF from Hi_Gear Engineering in the UK, and from Skyhook Engineering in Maine. The kits will run in the $2,500 and up, range -  not installed; unfortunately both beyond my (retirement) budget.


The other options I have been researching for, are gearboxes that might fit. So I have put together a table that when complete, will serve as a starting point for this whole project


The major limitation is that they must have a remote change. There are other small 5_speed front-engined, all-synchro gearboxes from the Datsun SR5, Sundowner and Mazda 2000 trucks; the Chevette /Isuzu and the 79 to 82 Corolla, to mention just a few. But all these have direct gear changes which puts the gear lever too far forward, and unless the lever is ridiculously short, and it will still be almost impossible to change gear.


One possibility is to look for a remote gear-change that can be added to one of the above direct-change gearboxes. Perhaps someone reading this will have some comments.


An acquaintance of mine, is in the process of installing the Honda 6_speed in his MGB, something I feel is a bad choice because the ratios for 2nd, 3rd and 4th, are clearly so low as to take advantage of the high_revving Honda 2000 engine. It means he’ll have to shift at higher (rev) points, not natural to the torque curve of the MGB.


Bud Kruger has graciously offered to host the table that I have started see :-


The information that I am first seeking, is to see if any of these g/b options will fit. And so the missing data for g/b length and the depth of the bell-housing should be a good starting point. So if anybody has access to this data, please let us (all) know. Also, of course I invite any and all comments not just from Canadians and Americans, but Brits, Scots, Aussies, Fancophones, etc.


So In order to bring all this information to a common point, I think its best to post them to this thread so we can all benefit, or you can e-mail me at the address at the left.


Gord Clark

Rockburn, Qué.

Updated 8 March, 2006

5 and 6-speed gearbox options for XPAG/XPEG engines
std TD/TF Miata 5 Ford Type 9 Datsun 210 Miata 5 Honda 2000 Suzuki  ² MGB MGA
4-speed 5-speed 5-speed † 5-speed 6-speed 6-speed 5-speed 4sp + od 4 spd
Approx. US $$ $2,200 $ 2,000 $ 750.00            
(New or rebuilt)
or auto re-cycler $ 800 $ 150.00              
g/b Length * 18-¾"                
Bellhousing 4-½"   Custom avail. From Custom avail.          
depth Hi-Gear - see pic from Skyhook
Standard total depth 23-¼           24"    
1st 3.5 3.136 3.65 or 2.98 3.513 3.37 3.13 3.513 3.44 3.65
2nd 2.07 1.888 1.197 2.17 2.269 2.05 2.17 2.167 2.214
3rd 1.385 1.333 1.37 1.378 1.645 1.48 1.378 1.37 1.374
4th 1:1 1:1 1:1 1:1 1.257 1.16 1:1 1:1 1:1
5th or O/D   • 0.814 0.82 0.846 1:1 0.97 0.821 0.082  •
6th   •  •        •   • 0.843 0.81   •   •  •
* = incl. Output flange but not incl.intput shaft
† = closer ratios avail.
² - Suzuki Swift engine uses Samurai gearbox. Geo Tracker - same engine, g/b
More Datsun info