Join Date: Nov 2009
Location: Lander, Wyoming
Doing a little winter maintenance on my '87 -A1 with 83,000+ miles on it.
So, just so as I can say I've done it, I totally disassembled the speedometer drive to inspect the base of the housing for wear. I have wiped out old grease & added fresh over the past 31 years. But as I've said earlier in this thread, Do Not Wash it Out. The base of my housing and the gears are in Perfect Condition.
The roll pin retaining my bushing appeared to have been purposely installed at a slight angle (Had to use hand held drill motor, not drill press. I had to try 4 different drill motors to find a chuck which would grip the 0.052" tiny bit. ), so as the tiny drill bit just skinned paint on the side of the housing which contains the seal.
In order to have enough room for a 3/32" drill bit & pin punch to be centered on the roll pin I needed to file a flat relief on the side of the housing. The base metal is not very thick to the butt of the roll pin and we only want to drill the aluminum, not the steel roll pin.
Due to the shape of the back side of the housing, my 3/32" pin punch was too short to drive the roll pin completely out, but I only needed it to clear the aluminum bushing, which it did.
Next I used a 12mm x 1.00 thread pitch Nut to screw onto the threads of the bushing and used a 2 jaw slam hammer puller to extract the bushing and the pinion gear.
My pinion gear has a steel thrust washer at the base & a copper washer between the pinion and the bushing.
Campfires pinion gear may have been missing the steel thrust washer from day 1, from the factory, which may help explain why his pinion gear wore deeper into the base of the aluminum housing, causing him to need to use a ball bearing & washers in the base.
I will say this was kind of a tedious / time consuming little job.
My best advise for most owners still is, Never Wash the old grease OUT of the speedometer drive.
Remove the drive tab & ring gear. Then use your finger to wipe out the old & glob in some fresh. Mash some fresh up into pinion gear area. Re-install the ring gear with drive tab