In the beginning...
Before photos. Like the rest of the tractor: dirty, rusty, greasy... but solid. Top views of separated transmission housing and cover.
Preparation. Uni-strut and angle-iron braces helped me safely move the transmission housing around. Hot day outside but I was under the shade to remove the old paint. The hat and wrapped transmission shaft helped control debris.
Preparation. Completely stripped and primer housing views.
Preparation. Painted: much nicer to handle and to look at.
Dis-assembly. Drive shaft with clutch-release bearing removed. Also view of the drive-shaft removed to replace internal oil seal.
Dis-assembly. Drive shaft housing can be slipped off drive shaft. Then put in vise to remove old oil seal.
Left: original oil seal was bad. The compression spring is visible which means it wore through the rubber seal and would leak.
Right: cleaned & new gasket in place. Pressing in the new oil seal (not shown) was an easy task. Bearings and race in good condition.
Dis-assembly. Left: clutch-release bearings - the one on left is original. Inexpensive and easy to replace.
Right: pressing out old bearing with large socket with correct diameter. It did not take much force to remove.
Re-assembly. Left: clutch-release housing with bearing removed.
Right: pressing in new bearing. It did not take much force to replace. Biggest challenge is keeping everything level/flush with mating pieces.
Re-assembly. Left: clutch-release bearing replaced.
Right: Everything put back together. New oil seal, gasket, clutch-release bearing, and clutch-release springs.
Clutch-release shaft. Installed new brass bushings. Top images showing removal of shaft pin to access bushing location in housing.
It is frustrating getting the wrong parts. Fortunately, the parts dealer I've dealt with has been great. I can't recall if this was my error or on their side. Regardless, they helped me sort it out and got the correct clutch release shaft bearings sent my way. Wrong parts are shown here.
The correct clutch release shaft bearing part # is 40-7508-A. New part (left) looks great and was pretty easy to coax into the housing. I recall doing some very minor sanding for the OD. Along with some goose-grease, it went in no problem. A dab of grease on the ID as well.
Clutch pin & shaft bushing. Left: rounded the end of the clutch shaft pin against a piece of railroad track I use for an anvil.
Right: opposite end of clutch shaft with new brass bushing seated in a dab of grease.
Clutch. Although located in the engine housing, it is posted here since it is a vital part of the transmission. Two before pictures.
Clutch. Cleaned the flywheel Left: new parts and alignment tool laid out ready for installation. Pretty straight-forward task.
Top right: wire-ties to secure the flywheel-crankshaft mounting bolts. New pilot bearing installed.
Bottom right: new starter ring gear installed - look at those beautiful teeth!
Clutch alignment. Left: validated the distance for all 3 clutch release fingers (which contact the clutch-release bearing) are the same distance from the clutch mounting plate. Also validated the ends of this measurement jig were the same distance from the flywheel. All was OK.
Right: this little jig ensures the drive shaft will mate properly with a centered clutch plate.
Shifter plate. Left: red arrow shows broken gear shift guide plate. Explains why tractor shifted "loosely" before. Replaced with a new one.
Right: glass-bead blasted transmission housing cover. Ready for priming and painting.
Re-assembly. Left: Rinsed all the gears using brand-new diesel fuel. Works well as it removes grime, old grease balls, but leaves nice coating on metal gears. No broken or worn teeth so I did not rebuild the gears. Gasket installed and ready for transmission housing.
Right: gear shift rod & rubber boot installed. The shaft beneath the steering column base is the starter-switch rod (see blue arrow).
How the gears work. Left: with the tractor in neutral, the gear shift move 'left-to-right' in the yellow region.
Right: This allows the starter button to be depressed which moves the starter-switch rod forward shown in the green region. Safety feature.
The top view (left) and side view (right) uses color arrows to match real-world images to the hand-drawn illustrations for point of reference.
Gear positions: 1 & 2. Left: first gear power path shown. Engine is toward the right with movement passing right-to-left (to drive shaft).
Right: second gear power path and positions shown.
Gear positions: 3 & R. Left: third gear power path shown. Engine is toward the right with movement passing right-to-left (to drive shaft).
Right: reverse gear power path and positions shown.
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