Dynahoe Starter Rebuilding
The starter developed an intermittent malfunction. Turn key, click, nothing.
Try again, works fine. I checked all kinds of things, it would work fine, then suddenly act up.
Eventually, in the middle of plowing the driveway, I shut down for a break.
When I went to restart, All I get is the clicking. So in the snow covered, partially plowed,
partially blocked driveway, I remove the starter.
Once inside, I remove the 2 long bolts that hold the end plate on. You can see the commutator
was moving back and touching the casting! The shim washer that is supposed to
prevent this is all worn and nasty looking.
Broken retainer.
After a little further investigation, I found the snap ring that holds the grey stop ring in
place was completely missing. When 12V is applied to the S terminal on the solenoid,
the plunger moves to the right. The fork pivots at "B", shoving the drive gear into position
for the gear to engage the flywheel ring gear. The gear hits the retainer, stopping it from
moving to far. The contactor on the back of the solenoid closes, applying power to the motor.
The motor turns in the direction of the arrow, and the splines cause more force to be applied
against the retainer. Since the retainer was broken, the retainer was pushed into the front
of the housing, and the reaction force pushed the armature back, causing excessive load on
the shim washer, eventually grinding the commutator into the back plate.
After much searching, I found this repair kit online at
ELREG.
Starter test
video before installing.
Here is a short
video after rebuilding, with a good battery.