1 - 4 of 4 Posts

10 Posts
Discussion Starter #1
hello , i looking information gearbox r53 for short box .

I can't find a short final drive

I know the 170 is shorter than 163, but I'm looking for even shorter


Premium Member
4,369 Posts
Thanks E-R53. Yes I can indeed help with these, the default is semi helical (noisy) or helical with an optional finish for additional quietness if preferred, installation varies whether I have just the box or the car, if you're overseas and wanting to install it there then you must expect to make adjustments to other components for clearance as required. These are actually marginally better installed to a pre-facelift BKD early box which has slightly longer gear ratios but work in the later box with even shorter 1st/2nd most noticeably.

The F/D provides approximately 20mph/1krpm instead of a factory ~23.5mph/1krpm in top gear and makes a tremendous difference, transforming the car ;O)

Different gear oil is strongly recommended, I use Redline lightweight shockproof which does have a slightly negative affect on synchro's which feel very slightly lazier during warm up in particular but this improves, just try not to rush a cold gearbox is my advice, you might not notice it. Use of conventional oil will accelerate wear of the new parts.

Semi Helical kit is £1,800 plus installation. The sound is still loud and especially at low speed can attract some strange looks, it is intrusive but it is nice on the move if you like the sound of touring cars 😂, it goes quieter from around 90mph. It is quite likely that the car will drive swiftly straight to the rev limiter in top gear with this conversion if making decent power.

I can also supply the F/D conversion already installed to a used BKD transmission with a new MFactory ATB differential, or other if you have a preference plus cost adjustment, the MFactory is a step up on the Quaife though and very well suited to this gearbox revision. The box then ready to fit is £3000, an ideal option for those wishing to retain their stock box for reinstatement.

I would highly recommend considering installing a GTT aluminium flywheel with a stock cover and bearing and utilising a Helix organic sprung clutch disc for optimal performance supporting the final drive in getting the engine spun up fast into the cam range and aiding shift quality.

If you want to go a step further then I also have a complete dog engagement gear kit to run with the F/D conversion, on these the gear ratios are improved bringing 1st and 2nd to somewhere between the F/D kit and stock perhaps and has closer ratios. Gears are straight cut and are helping the F/D's give closer to ~18mph/1krpm. There is no requirement to use the clutch when upshifting and shifting down is also possible clutchless although most use it. Once practised, use of the transmission is reasonably straightforward and although not really practical it could even be used on the road, it needs additional planning for down shifts while slowing etc, timing and shift action are the main learning curves.

In the U.K. any interested in these can have these demonstrated in my own car on road or sometimes on track, currently with the full conversion installed.

A very brief road clip:
A brief track clip:

1 - 4 of 4 Posts