This is an optional Schumacher Spec R Gear Differential, and is intended for use with the Schumacher Mi4 touring car. The Spec R gear diff for Schumacher Mi4 uses Mi4CX sliders and specially designed outputs. It will also fit other Mi4 models which use blades. Schumacher team drivers have been using Schumacher 70wt shock oil in the diff for best results.
NOTE: It is recommended to fit the small shims included against the output shafts, this is not shown in Spec R's instructions.
Spec R Build Tips:
- Assemble the entire Differential unit
- Rotate the Differential from each side to make sure the internal gears operate smoothly
- Diff feels coarse when the internal gears are too tight. Open the Diff and use fine sand paper to sand the flat side of the large internal gears, re-assemble and test again. Fill the Diff with diff lube when Diff feels smooth.
- Diff feels very loose when the internal gears are loosely meshed, add a 0.1mm shim on the bottom of the larger internal gear, re-assemble and test again. If the diff operation is still loose add another 0.1mm shim to the bottom of the opposite large internal gear. Diff should feel moderately smooth but not too loose or too tight. Fill the Diff with diff lube when ready.
- Fill the Diff to about 1/2 of 2/3 full. Do not over or under fill the Diff.
Watch this handy video for detailed building tips: