I just rebuilt an HD reverse motor for my buddy. It always had a weird gear sound and slow speed but finally quit working completely.
Do yourself a favor, remove the body. 8 bolts some plug in wires and 2 people will make your life much easer.
Three things I found during tear down.
1. The brushes, although they were still in usable condition, were sticking in their housings.
2. The rpm reduction gear compartments had lots of metal grit in the grease used to lubricate them.
3. Small ball bearings.
I completely dissembled the motor including removing the drive gear and actuation arm from the front housing.
Everything got cleaned and inspected. The reduction gears, 6 of them, all looked good including the motor housing ring gear.
I was surprised the reduction gears looked as good as they did because of the amount of grit I was feeling in the grease. I wasn't concerned
with the condition of the armature because I wasn't reusing it. Luckily, I chose correctly because even though the old one was still functional,
the worm gear on the armature that drives the reduction gears was worn badly. This explains the weird noise and grit in the old grease? The 6 reduction gears looked hardened and had almost no wear.
The grease used in these reverse motors is not your conventional bearing grease. It's an extreme pressure gear grease w/moly. I chose 3% moly, you can
get 5% moly online. Just thought I'd let ya'll know this in advance because it's not stocked everywhere.
The kit I used included the front housing bearing, rear armature shaft cover bushing, brushes and plate, armature and solenoid.
I installed the bearing in the front housing. There's a spiral lock ring that holds that bearing in. Next the drive gear assembly and actuating arm
re-greased as from the factory.
THIS IS IMPORTANT ....... there are 2 small ball bearings that drops into the bushing hole of the gear reduction plates. There are 2 plates that hold the speed reduction gears. Place 1 small bearing in the bushing hole of the first plate before greasing and installing the reduction gears. Now grease. Then install the motor housing over the first set of reduction gears.
Next install the 2nd reduction plate into the first. The 2nd plate gets the other ball bearing in its bushing hole. That's were the armature shaft will go later. Now, install the reduction gears and grease. I used lots of grease.
The small ball bearings apparently keep the shafts from bottoming out in the bushing holes.
Replace the end cover bushing if it came with your kit. Lightly grease that bushing. Install the brushes and plate on the armature and place the plate in the end cover and secure.
Re-install everything else in the reverse order you removed them.
I wrote this because I could not find any information on the small ball bearing that rolled out on my work bench during disassembly or
the gear reduction.
It was only after finding the 2nd ball bearing that lead me to discover were the 1st one came from.
My reverse motor rebuild works perfect. It no longer has that grinding noise it once had and the reverse speed is back to normal.
Hope this helps someone out there. If I ever do another one, I will do the same kit seeing the wear and grit I found.
I'm beginning to see why so many have had failure's with just replacing the brushes on these reverse motors.