SMCO Honda S40 Transmission
Our D series transmission start with a S40 gearbox core. The boxes are first power washed and then disassembled. The cases are hot tanked and then vapor blasted to a better-than-new finish. The hardware is glass beaded and then re-plated in yellow zinc (again better than new).
The internals are all redone. New bearings, new seals, and new carbon synchros. We re-shim the main thrust washers internally, which most rebuilders typically do not do. The shims are no longer available from Honda so we laser cut and machine grind our own from spring steel. The synchro rings are M factory carbon units, the best you can buy.
We also have an option for an M factory LSD. This is a Torsen type differential, therefore it will never wear out or make noise, and will put power to both wheels, increasing traction and allowing you to get on the power sooner at corner exit. We recommend this addition for anyone looking to get the most performance possible from their car.
For exclusively street driven cars the factory open diff is suggested as it puts a little less shock through the steering wheel and provides a more relaxing driving experience.
3 weeks lead time
Long first gear
We install this longer first gear whenever we do a custom build. It makes taking off the line smoother and it also reduces torque steer. This makes first gear more usable and tractable especially when used with 10" wheels.
We install these in all our in house builds and when ordering a rebuilt transmission from us, we install this final drive with every gearbox we sell
3.1 final drive
This final drive makes the gearbox much more tractable, giving longer gearing and is excellent at reducing torque steer and achieving the best highway manners.
Running 165/70R10 tires, you will be doing 129.58 km/h (80.52 mph) at 3000rpm making for a perfect cruising rpm while still having power to pull in 5th.
We install these in all our in house builds and when ordering a rebuilt transmission from us, we install this final drive with every gearbox we sell
Optional M-Factory LSD
The LSD by M-factory is our differential of choice. Not only does it put the power down to both wheels, giving you the ultimate in traction and corner exit speed, but because of its gear driven design it will never wear out or make noise.
We reccomend this diff for anyone looking to get the most performace out of their car. The added traction from the lsd will help power out of corners at the expense of a bit more lively driving experience.
