Ok You should probably assume that the smaller ID washers go on the commutator end.
The larger ID metal washer goes on the armature at the drive end.
The black one is rubber, right?
It goes on the drive end shaft against the end plate bearing and the fingered washer goes against that with the nubs facing the end plate.
There ought to be wear marks on the nubbed washer which match the big ID washer fitted to the armature. Verify that.
Clean the commutator with alcohol or brake kleen. It needs to be clean. Clean the brushes, too.
Place the armature into the field housing from the end opposite the brushes.
As you insert, Guide the brushes onto the commutator.
Lube the shaft and or the bearing, which you should have inspected for wear. No oblong bearing contact surface.
Place the smaller ID washers on the commutator end shaft, and place the commutator end on and align with the guide features.
The drive end gets the larger ID thrust washer on the armature.
Inspect the drive end bearing for oblong wear. Shouldn't, have any.
(here's where memory fades)
The nub washer goes on the armature with nubs facing outward.
The rubber washer goes next. And the drive end cap goes on next, align the washer nubs to clear any casting webs, And the cap alignment features with the field housing. (Don't forget the bearing lube.)
Insert the long bolts. (I can't remember which end the heads are on.) You'll have to check for installation clearance. The motor itself won't care.
When it is all together, push the shaft in and out at the drive end to check end play, run out, or binding. Shouldn't be more than a washer thickness movement. I'll say 25 thou, about.
If all is well, Check the power post to case continuity. It is going to be very small, nearly a direct short. But, you should be able to discern a small difference between probe ends touching each other directly, and then on the power post.
Zap it with 12v (short bursts), and listen for rubbing noises armature to field. It's a torquey thing, so hold on to it for the test.
Issues? Report back. I'm doing this from memory. My parts stores are 700 miles away, at the moment so I can't check my process.
Cheers,
