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Friday, May 1, 2015

Gearbox Dismantle Complete

A flurry of activity after getting home from work today. I was able to completely remove all of the gearbox internals AND the clutch. Turns out the only damage that I could find with the gearbox was the 3rd/Top gear hub that I had already found. This time, I was able to locate the rest of the gear teeth in the bottom of the gearbox housing.
Maybe I could make dentures...
Well, I guess I take that back. The detent balls (or, more properly, their springs and that are about the size of a pencil eraser) that are in the synchro hubs were pretty much either busted or otherwise compromised, so they will be replaced across the board (love the cheap fixes!). However, those little bastards are quite the pain to get out and I've yet to get them all.
Some of the detent balls. That extra peice in the center is part of a broken spring...yeah, not right.
Everything else looked good...better than I expected, actually. As you can see in the picture above, that ring of metal sitting between the main shaft and the hub is (or was) the main shaft circlip. You are not supposed to re-use them so I took this (and with advice from the forum) as to mean that it was expendable and tore it up to get it out. The main shaft gears slid right off after that (as expected).
1st/2nd gear hub assembly, with synchro (which is brass, but dirty, obviously)
Once I was done sliding all of the pieces-parts off the main shaft (and after taking lots of pictures, which I won't bore you with, so I know how everything goes back together) it was on to removing the input shaft. I had been trying to knock the bearing out by directly knocking on the bearing casing. This time, since the main shaft was removed and I had a bunch of room, I decided to put the fat end of the punch inside the recess in the input shaft (where my absentee needle bearing should go) and knock it out that way. A few sharp, but not really hard, raps and it was on its way (i.e., it didn't take much once I figured out the better way to do it).
Note that I used the "fat" end of the punch (turned around from this picture) so to minimize damage to the input shaft recess.
The cluster gear (a.k.a., laygear cluster) lifted right out after removal of the input shaft. My inspection didn't find any damage or excessive wear. In fact, I was pretty happy with the condition of the gears, original or not, who knows. There are a few parts in here, as you can see on the lay shaft in the picture below, that need to be oriented properly for re-assembly (thrust washers and such).
Looks good to me! That's the cluster (lay) shaft above it, spiral cuts for oil flow (I assume).
After the tear down and inspection, it was on to the clutch. Crappy research on my part led me to believe that the crank pulley nut was 1 13/16". This is correct for later models but not for my Mk1 engine. So, I wasted several days for Amazon to send me a too-large socket when I could have just used my adjustable wrench set to around 1 1/2" or so to prevent the engine from rotating to enable me to remove the clutch...~$20 lesson learned (sometimes I force myself to keep and display my mistakes to remind me to, in essence, measure twice and cut once...seems like I need to continually re-learn this lesson).

The clutch came off with no problems and the inspection turned out pretty well. No damage and, from what I can tell, minimal wear. The gouge in the release lever was definitely caused by the clutch pressure plate bolts, but they were much tougher and didn't suffer any direct damage.
Release lever plate. But, those bolts in the picture are what rubbed into the release lever, I believe.
The pressure plate (the British terms are different from what I am used to, though it may be the totally different design of this older clutch) looks good and, outside of needing a cleanup, I am pretty sure can continue service.

The pressure plate...dirty, but surface looks good with adequate friction grooves.
The same goes for the driven plate (again, Brits).
Looks good...I decided to clean up one brass rivet...just because.
So, all in all a good day and it only took a few hours. I'm going to go back through the gearbox tomorrow and make sure I understand what I need and maybe partially re-assemble it if necessary to measure clearances as required. But, again, based on what I found, I think the gearbox is pretty solid and I don't expect to require much work outside of the expendable wear parts and the one synchro hub!

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