After a marathon effort I have now installed a 1973 swingaxle transmission into Marvin (1966 swinger). I don't know I'd do it again. Of course, later VWs had longer axles so I had to swap over the axles and tubes. Not too bad, except for the massive circlip that retains the axles. Very hard to get out, just as hard to re-install. Maybe a workbench would have been better than the front lawn as dusk was coming. Anyhow, eventually got them off. Now to start on my old trans, and perform the same operations. A lot of mucking around later, I've got 4 axles, 4 axle tubes and two transmissions. Glad I only have to reinstall 2 of each. Now to put the new trans in the car. I had tried to be smart, installing the trans with just axles attached, to add the tubes later. Bad news, as you cannot access the bottom retainer plate nut to torque it up.
Out came the trans again. Torqueing up the axle tube retainer plates is a trial and error procedure - you add a gasket, torque up and then check free movement of the tube. Not enough play, undo everything, add another gasket, torque up and try again. One side took 4 gaskets (rather than the thicker shims) and the other side took 3 gaskets. The nose cone was very different, and the nose cone mount totally different, so they had to get switched over as well. The transmission-grounding strap on the new box was too short, so the old one got swapped. Removing the axle tubes means disconnecting the brake hardware, so that all has to be bled when you put everything back together. But in my case, I had old fluid in the system so I changed the fluid as well – which I discovered you do in the reverse order to bleeding the system. To change the fluid you open the longest run of brake-line from master cylinder to wheel and empty it by pumping the brake pedal, working down to the shortest run of line at the closest wheel. To add the new fluid you open the shortest line and work up to the longest line. Then you go around again to bleed the system properly working from the longest line to the shortest. Adjust the two brake lining adjusting stars on all four wheels, and the handbrake cables which got disconnected when you pulled the trans. Hey, what's time if not for working on our toys??
Oh yes, the engine replacement was the hardest I've ever had to do as well. I forgot about the flywheel didn't I. You know, the different diameter between 12V and 6V flywheels? I decided to try the American backyard enthusiast’s method of clearancing the bell housing. Whack the engine in as good as you can, fire up the engine and let the flywheel do it's own grinding, and may the toughest piece of metal win. I modified that barbaric practice by turning the crank by hand to do the grinding, and something just shifted and the engine went on - well, I winched it on using the starter motor bolt and nut in the opposite side bolt hole, pulling the engine into position until getting the bottom two nuts on the studs and using them as well. Did you know, a 6V starter doesn't fit a 12V bellhousing properly either - it uses a different bush. Solution - drive the 12V bush out and just whack the starter in. Just make sure it's snugged home nice and tight. The shaft sits in mid-air - I think that should help with cooling the starter, right? On top of all this, I used vast amounts of degreaser, nylon brushes, steel brushes, a brass brush, and elbow grease to shift an accumulated 33 years of crap from Marvin's trans and chassis frame horns, plus just 26 years of gunk on some bits of the donor trans (a lot of it was cleaned up by the guy I got it from, thanks Leigh).
Don't forget to have purchased a set of axle gaskets and ring seals like I forgot. I also got an axle bearing stuck halfway along the axle for a day. Anyway, the engine is in, brakes done, wheels on. It all now looks great. Except I forgot to reconnect the fuel line. And adjust the clutch cable. So I started that and snapped the wing nut on the clutch cable. Just took 1.5 hrs to remove. Wish I was billing for this. OK, fabbed up a replacement set of washers and nuts to substitute for that. Hook up fuel line (spilling only 250ml of petrol down my arm while doing it), axle nuts torqued and pinned. Leave on car stands and see what happens. Marvin starts first go (second crank). Terrible screeching. OK, it's just the flywheel doing its thing to the bellhousing. Put up with it for a while. First gear - well, super heavy clutch, but easy change. No vibration either, but still screeching. 2nd. 3rd. 4th. under the car, can see smoke and alloy discolouring from heat. Hhm. Rear wheels don't turn. Handbrake is on, why didn't the car stall. Handbrake off. No movement at rear wheels. I can rotate them by hand, but the engine won't turn them. Oh no, have I snapped the crankshaft? Destroyed the flywheel? Broken the mainshaft of my new gearbox???
Engine off (neighbours are all watching and listening, this project has been stinking up everyone's house for a week now). Crawl under the car again. I can turn either rear wheel any direction I like. Same direction, opposite, reverse, no difference. Put shifter in first, same result. Coupling come loose? Back seat out, inspection flap open - all in place, and hooked up. Son changes gears while I listen to box. Appropriate clunking noises emanate from inside the case. As I look at the dripping oil I know the awful truth - the engine has to come out again. Yank the engine. Then I discover the other difference in the two transmissions. Throwout bearings. Totally different. And the new one has a shroud around the mainshaft that projects forward - that was what was preventing the engine from going in previously. But I had done such a great job of winching the engine in that I very neatly flanged the end of the shroud with the clutch plate and jammed the throwout bearing. Hence the screeching on startup, and the burning smell. Then, while son pumps the clutch pedal so I can prise the stuck throwout bearing off, my nifty fabbed up nuts fly off the end of the clutch cable. I still don't know if the threads are stripped. I don't want to know right now.
Now it's a different throwout bearing right? Different method of securing it to the support arms, different diameters to fit different clutch sizes, different support arms on different actuating rods in different size holes with different size bushes. But I'm going to swap the clutch actuating lever, rod, and bushes, support arms from my old trans case into the new one. Aren't I. No I'm not. The dimension I didn't measure means it won't fit without a large bush I don't have. Ring my mechanic, saying the throwout bearing is different. Oh yes, I forgot about that, he says. Actually that's because they started using a different pressure plate. You've got a 180-mm clutch haven't you? Now I'm sweating coz I know they went to a 200mm clutch, mine is 180 and a 200 will not go on my flywheel - I can only change flywheels. But, he finds a late style 180-mm pressure plate for me. OK, grab that, and a new throwout bearing, and new guide (I'd had to cold chisel the old one to get the burnt throwout bearing off). Install it all, engine in, and Brrm. We are going. And it's great. The pain is nearly forgotten. But I won't do it again tomorrow!!
Moral of the story? Never accept on face value that it will bolt straight in. Measure everything in sight and think if they changed one component, how many other things could they change?
Jeff
66 Aussie Beetle
Marvin the Revbug
Gross Fahrvergnugen