18.75 to 1 Outside Drive Reduction Staton gearbox, it is CNC machined, has Six High speed Double sealed ball bearings, 1/2" thick gears and a 5/8" output shaft with a 3/16" key way and snap ring groves.
This gearbox will mount to the Honda GX50, 49.4cc GX35, 35.8cc Four Cycle, Zenoah G430RC (G43L) 41.5cc 1.97 hp two cycle, Tanaka Pure Fire PF-4000 (4210) 39.8 cc 2.2 hp Two Cycle and other with the same clutch rotor and bolt pattern, NOT INCLUDED.
We also make adaptors for the Honda GXH50 and special 3 shoe clutch.
It has a 5/8" OD output shaft with a 3/16" key way and snap ring groves.
Over all length of the short shaft (standard) is 0.94" long with a usable length of .75".
Cast Alum. One of our web sites will be engraved on the outer cover.
MADE in the USA.
Note: Engine, engine bolts (6 mm x 1.0 x 30 mm SHCS, Black 8.8 Socket Head Cap Screw, black, Metric) ,sprocket and other parts are extra - Not included.
Be sure and add about 10 oz of # 1 Lithium Multi-Purpose Grease (Max Lithium Multi-Purpose Grease NLGI # 1.5) to the gearbox before bolting the cover on.
Do not use any weight of oil as it could enter the clutch drum / clutch rotor.
Use Four 6 mm x 1.0 x 30 mm Socket Head Cap Screws. Place blue lock tight onto the lower 3/8” of threads to attach the lower / engine side of the gear case to the engine.
After 9-17-07 all 18.75 to 1 gearboxes have the 1-3/8" Int. snap ring that separates the bearings.
The clutch drum / shaft with 3/8-24 male threads.
Place the some Blue or green lock tight where the lower bearing goes. This will help lock it to the shaft so it does not spin.
Then add ONE 5/8” x 14 gage machined washer. This is to keep pressure off the inner races of the bearings.
Add Blue or Red lock tight to the 3/8-24 male threads and thread on the 12 tooth hardened gear.
Make sure the 3/16" round x 3/4" long Location Pins are installed by both fulcrums (where the 3/8" thru holes are). Using a rubber mallet tap the cover of the lower / engine side of the gear case.
Be sure and install all 8 of the ¼-20 x 1-1/2” long Socket Head Cap Screws.