SMCO Honda S20/S40 Transmission

Our rebuilt S20/S40 gearboxes are from base model civics with hydro clutches and 3.722 final drives. The boxes are first power washed and then disassembled. The cases are then walnut blasted and then vapor blasted to a better-than-new finish. The hardware are all glass beaded and then re-plated in yellow zinc (again better than new). 

The internals are all redone. New bearings, new seals, new synchros etc. We re-shim the main thrust washers internally, which most rebuilders typically does 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.

All gearboxes come with upgraded detent springs for a better shift feel. 

From there we have a few options available:

The base model is as is, with the factory open diff and stock gearing. 

We also have an option for an M factory LSD. This is a Torsen type so it will never wear out or make noise, and will put power to both the wheel, increasing traction and giving more power at corner exit. 

Another option is for a longer first gear. We swap this gear in to make taking off the line smoother and it also reduces torque steer. This makes first gear a bit more usable and tractable especially when used with 10" wheels.

We can also add a 3.1 final drive. This makes the gearbox the most tractable, giving the longest gearing and is the best at reducing torque steer and the longest gearing for the best highway manners.

We can do any combination of those two options.

3 weeks lead time