December 31, 2013


Well, it is New Year's Eve and Wall-E is up on blocks with the entire rear end disassembled. It all started in June. Wall-E and I were smoothing out our driveway, preparing for a summer camping event, when something under me started rattling and then Wall-E would not move. I was able to get him out of the road before he stopped rolling but there was no moving him under his own power.

After the event, Walt and I went out to drag Wall-e up to the landing where I could work on him more easily. We decided to use a come-a-long to pull Wall-E under the bring since I wanted to store him under cover and I figured the work that was needed would take a while.

The upper drive shaft protruding out the front end of the transmission.

First thing I did was to remove the propeller shaft which transfers the power from the engine to the transmission. My next step was to consult with the crew at Zimmerman Oliver Cletrac. While their website may be under construction these guys really know their stuff!

With their guidance, I grasped the protruding end of the transmission shaft and tried to wiggle it. It moved. A LOT! This indicated a failed bearing in the transmission. That discovery was disheartening since the transmission would likely need to be rebuilt.

Given the amount of work that Wall-E needed and my limited mechanic skills, Wall-E just sat there looking a bit forlorn until Pat showed up to join us for the fall. So by the first of October, Pat and I started taking Wall-E apart.

Off with the Chair!

Removing the seat, battery, and rear transmission cover went smoothly and gave us a limited look into the transmission.

Seat and battery removed. Draw bar resting on ground.

A look inside. The steering bands surround the differential and the upper transmission shaft is in the top center of the photo.

Wall-E uses lots of tapered roller bearings which come as a set. The bearings are mounted in a cage and set on the "inside" race which mounts on a shaft. The "outside" race is pressed into a housing and in the next photo the race shows lots of wear from the shaft moving about.

Close up of the damaged race on the upper drive shaft.

So now we know that the transmission need to be removed to evaluate the extent of the damage and rebuild the transmission. After the drive bar was removed we started on removing the tracks.

The Master Pin which gets removed allowing the tracks to fall away.

The Master Pin has a slot and key. The key gets removed and the pin gets driven out. We used a large bolt as a drift pin and a sledge hammer to drive the master pin out. We also used the vise-grip pliers to hold the bolt.

Tools for removing the Master Pin. The Master Pin is between the bolt and the vise-grips.

With the Master Pin removed and the track lifted off the sprocket (rear) wheel t he tracks just fell under their own weight and the front wheel just slides forward off the frame.

Track and front wheel removed.

Since practice makes perfect we get to perfect our skills and do it all again on the other side. Next we need to remove the tie-bar. It is a threaded bar that extends the full width of the tractor which means that my Oliver-Cletrac is a Model OC-3 42.

Most everything we get to do twice and most of it is harder on the left side.
The tie bar is the full width of the tractor and attaches to the main springs on the track frames.

With the tie bar removed, the track frames roll forward on the tracks. Then we removed the rear sprocket wheel, disconnected the rear hydraulic cylinders and loosened the loader frame assembly. All this so we could get the Final Drives off.

Final Drive exposed now that the rear sprocket wheel has been removed.

The Final Drive Assemblies came off smoothly if not easily once we loosened up all the connections between the tractor and the bucket assembly.

Time to move inside the transmission housing: the steering band assemblies (brakes) and the differential came out next. Finally we can remove the transmission housing from the frame and have a look inside - but not before we remove several more parts, including the clutch pedal, so we can gain access to the transmission housing bolts.

Success: The transmission housing has been removed and is sitting on the table.
A look inside from the differential area shows the worn race and exposed bearings on the upper shaft.

Time to open up the transmission and take a look inside. I was so excited to be nearing the mid-point that I didn't have my camera with me but when we removed the shift box we found loose roller bearings and damaged cages in the bottom of the transmission housing.

A look at the damaged races once the shafts and gears were removed.

We started ordering parts in early November and still have more parts to order before we are finished. All of the bearings in the transmission area and most of the gears need replacing but we have reached the turning point where we are starting to put things back together.

Pat takes a well deserved break in the transmission seat. =)