Harley Six Speed Transmission Rebuild - Part 4

If you have dismantled your Harley six speed transmission to this point, it is probably because you need to replace your Harley main drive gear bearing (sixth gear).

Speciality Tool

At this point, the main drive gear needs to be removed. To remove this gear, a specialty tool is needed. The tool pulls the gear through the main drive gear bearings’ inner race. It is good to spray the gear with a little lube before attempting to remove. The outer surface is typically rusted. The Harley main drive gear bearing will begin to break apart as you remove the gear. That is normal. When the main drive gear is in your hand, you will notice that one of the bearing’s inner races has remained on the gear. This race needs to be removed if you are to reuse the original main drive gear.

Reuse Or Replace Harley Main Drive Gear Bearing

Typically, this gear will be reused unless it is broken or damaged as it is very expensive to replace. There are a number of ways that this race can be removed. Mike shows us how to clamp onto the race and press it off with a hydraulic press. Remove the main drive gear inner seal (or, mainshaft seal) and replace. Then, slide a new o-ring over the gear and set it aside; ready for reinstallation.

Remove & Replace

Pry off the main bearing seal and remove the bearings’ retaining clip. Note that the flat side of the clip faces the bearing. The rounded, concave side faces away from the bearing. Now, it is possible to remove the remaining half of the Harley main drive gear bearing. The fitment if the remaining bearing and race is not very tight. Both pieces can be easily tapped out with a plastic hammer or a brass drift. You will need to use a specialty tool in order to install the new bearing, the main drive gear, and even the main bearing seal.

Next, we will prepare to reinstall the gear set back into the transmission case.