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Post 29
October 2015

Transmission Breakdown - Random Stuff Along the Way

I’ve broken all of the transmission components down, cleaned everything up, and inspected for damage. I’ve also roughly assembled everything in order to test fit everything and firm up a list of parts that need ordering.

I order parts from the UK. The downside is that everything takes a couple of weeks to arrive. Because I ordered three new gears the total cost would have been too much to stay below the duty threshold for a single shipment, so I’ll have to order in two stages. Also, the new gears will need to be fitted to the mainshaft before I can check the end float and order whatever thickness spacer is required. So it’s a minimum of about four weeks to get everything back together.

Anyway, I’ll do a more thorough post when it comes to putting everything together, but for now, below are a few photos of a few interesting bits that occurred. Otherwise the whole dismantling process went pretty much as per the manual.

land rover series 3 mainshaft nut

Mainshaft Nut

I didn’t need a special tool to get this undone. Once the locking tabs were bent back, a light tap with a punch was all that was required. I tapped it with a punch before trying, but it was probably loose enough to undo by hand. I’ll probably end up making a special tool out of an old socket so that the nut can be reassembled with the correct torque. But for disassembly, you probably don’t need to bother.

land rover series 3 reverse gear

Reverse Gear

As you can see, reverse gear is stuffed. I think the cause of this a leak in the clutch slave cylinder, which had spread oil all through the bell housing, which meant the clutch to had a tendency to stick. Without a synchro, reverse was effectively being slam shifted every time.

land rover series 3 selctor shaft rusted cover

Transfer Box Selector Cover

This is a small metal cover that keeps the ends of the selector shafts out of the weather where they protrude outside the transfer box. The cause of this hole is rusting from the inside. The metal cover is supposed to be sealed to the transfer box case, and packed with grease. Instead this one was full of crusty dampness.

land rover series 3 selctor shaft cover

Patch welded on. Not my best work but good enough for a crusty old Rover.

land rover series 3 transfer box bearing preload

Transfer Box Output Bearings Preload

Setting the preload with a fish scale. Exactly as per the manual.

land rover series 3 transfer box bearing preload

Transfer Box Output Bearings Preload

And then stuffing shims in the gap until it could take no more. All of the shims that came out went back in bar two of the thinest. Which makes sense. Two thin shims worth of thickness is probably about how much things have worn since new.

land rover series 3 mainshaft snap ring

Getting the F***ing Snap Ring off the Mainshaft

Excuse the language, but this was a b**ch. It took me about an hour to get the snap ring off, and I have flat bladed snap ring pliers. Exactly the correct tool for the job.

Snap ring pliers were useless. It’s possible that if you had pliers just the right size and shape, they would work. The problem is that because the snap ring is well below the level of the gear, there is no room to wiggle anything to actually move the snap ring away from the groove once the ends are spread apart.

After many failed techniques, the one that worked (not well) was to twist the snap ring out of the groove with a small flat blade screwdriver slid in between the splines of the shaft, and then jamb a split pin in behind the snap ring in the newly opened gap, one spline away from the screwdriver. And repeat all around. One slip and it all starts again. Finally when the ring is held fully outside of its groove, it can be shimmied up the shaft to freedom.

land rover series 3 mainshaft peg missing

Missing Mainshaft Pin

It’s lucky I persevered with removing the snap ring, because the mainshaft is missing the pin that is supposed to hold the thrust washer and bronze bush in place. This was not visible before removing the snap ring and pulling the gears off. On its way out the pin has mangled the bronze bush.

land rover series 3 mainshaft peg missing

Missing Mainshaft Pin

There it is. The twisty bit is bronze sheared of the bush. The thing that looks like a drop of water is actually a piece of the pin worn smooth. There are a couple of other bits not visible. I guess most of the pin was broken down to the point that small bits disappeared into the oil.