More Power to Your Elbow - More Speeds in your Gearbox

I mentioned in my alternative tuning article in this issue that a decision was taken to strip my five speed gearbox and observe any possible wear problems. After all. it had covered an unmerciless 12.000 miles since installation. The box was picked up by Dave Hirons of Tran-X and returned to its place of birth where Mike WaIters stripped it for inspection. No real worries were evident. although a couple of areas needed closer inspection. Following this. and previous experiences with the standard gearbox castings. a couple of changes to the system were made to further enhance longevity.

Maybe an unnecessary move since a gearbox fitted by Richard Longman & Co. to a reasonably powerful road unit has covered 24,000 miles without a hitch. Still. we always have our customers best interests at heart - the best being only just good enough. In fact. unlike other five speed 'box choices. so far we have had no failures at all. The only problems we have had were this casting inconsistency problem. We have now eliminated this from the equation by the brilliance of Dave Hirons.

The journey through the gate is as balanced as it always was, with no gear selection notchiness and ease of reverse gear selection from the superbly crafted gear lever base plate. Even the gear lever bias spring seems to carry just the correct amount of tension. As I have previously said, it almost feels like the fifth gear was always there, just needed that final link to make it operational.

In fact, so successful has this project proved. a special limited production six speed has already been planned. I know there is one already in operation. but ours will be a straight six speed with the sixth gear ratio one to one as it should be. Not the easily attained two overdrives - which probably makes diff ratio selection a nightmare. It will be limited in production numbers as the cost of producing such a technically advanced unit is high. We have even covered semi-automatic operation - an entirely feasible design already being penned by the mighty "Hirons·'.

Incidentally, the aforementioned "Hirons" consistently amazes me. On a recent visiit I stumbled on a real trick dog box set up he has been playing with. In its assembly, I have never seen an engagement select so quickly, so perfectly, every time. And, believe me, I compared it to all other types of dog engagement. I am desperately twisting his arm to go into semi production with this set up. but he refuses to be drawn at this point. Why? Because he is concerned the box might not make 1,000 competition miles! So self effacing is this man with ultra deep concern for his customers/users and the perfection of his products.

This visit also brought about an interesting discussion on the why's and wherefores of dog boxes verses the synchro box. I'll be covering this in the next Mini Tech News along with helping to recognise the good and bad of straight cut gears - be they cluster assemblies, drop gears. or final drives. Ifs VERY interesting. I promise!

Keith Calver

Importation rules regarding vehicles are very specific: Only those over 25 years in age may be brought in to the USA without compilance to Federal Motor Vehicle Safety Standards (FMVSS).