Have an early 90s Komatsu wa420 loader that we need to replace the rear pinion seal on. Looking for input on the process of doing it. The service manual isn’t much help. Will the rear driveshaft come off without moving the axle?
Haven't done one that old but done plenty of Komatsu loader ones, U can use a bottle jack to lift up one wheel or use stands under frame, lift machine with bucket and put them under and let it tilt forward. On the newer ones -3-6-7-8 ones just undo the drive shaft, drop it out, remove the flange nut, slap the new seals in with some 3bond around the outside, might need a new flange given the age of yours or seat the seal deeper and send it, tension the flange bolt back up and the drive shafts and off ya go
Jack up one wheel to unload the drivetrain. Remove the drive shaft, there is enough room once both sides are unbolted. Remove the pinion nut on the yoke. Remove the seal. Install new seal, install speedy sleeve on the seal area of the yoke. Install yoke on pinion shaft, new O ring, washer and nut. Torque to spec and reinstall the drive line, drop the jack and top of the oil level.