Well lacking anything better to do with the head being looked at and the steering box rebuild on hold I figured it was time to start the reassembly process. The flywheel, clutch parts (minus the springs), and throw out bearing parts have all been cleaned in my electrolytic rust removal vat. I also threw a coat of high temperature paint on everything but the pressure plate and flywheel.
The first step is to get the rear main seal and it's housing back in place. I stuffed some paper towels in any holes in the holes in the bearing and it's cap to keep gasket material out of the engine. Then using my torch and chisel method scraped the gasket martial off the block and the bearing cap. I used a little bit of grease to tack the gasket to the seal housing and then installed it without bolts on the crankshaft end.
The bolts that hold the housing to the cap are secured by lock tabs that have ears which bend up and keep the bolts from unscrewing. I couldn't get these lock tabs but they're easy enough to make. I wouldn't recommend reusing the originals as you run the risk of metal fatigue (go bend a paper clip back and forth a few times) cracking off an ear and having a bolt unscrew.
I started with some 20ga sheet metal I picked up for change at the local welding supply store. A rectangle is cut out and then, after being hammered flat is clamped to the sheet metal. Then I trace the outline of the lock tab. Graphite pencils don't work on steel, the usual solution is to use a grease pencil or steel chalk but I didn't feel those were accurate enough. Instead I took a piece of coat hanger wire and ground it to a point til it was glowing and then quenched it to harden it. I then scratched the pattern into the sheet metal.
First I center punched the holes, making a nice dent in the metal for the drill bit to grab onto and drilled the holes. Then as much of the metal is possible is cut out using the sheet metal sheers and the remainder was remove with the bench grinder (a cup of water was necessary to keep it cool). Above is the first one I made before it's final grind and it would've worked just fine but I ended up replacing it with another I turned out. I made all 7 (3 for the flywheel) in just under an hour and a half (my right hand refused to speak to me for the rest of the night).
A fellow on another forum pointed out to me that I should be careful of stress cracking on the castle nuts I made. Square edges cause stress in metal to be concentrated, this is why crankshaft journals have fillets and airplane windows are round (look up the de Havilland Comet). The surface finish can also sometimes cause this but a grinding wheel usually leaves a decent enough finish for this. I went ahead and reground my castle nuts with the dremel and kept this in mind when making the lock tabs. These tabs aren't under a lot of stress but it's a little peace of mind. All the corners are gently rounded instead of sharply cut. Again I hadn't made the final grind in the photo above.
A photo of the same lock tab installed along with one of the originals.
Here is the rear main seal housing and starter housing installed with the lock tabs bent down. The starter housing went on after all the bolts had been snugged down on the rear main housing. The lock tabs are bent up slightly before installation. Then the bolts are torqued, bent over with a screw driver, and tapped into final position with a drift and hammer.
There are no torque values in the book for these bolts (or much else for that matter) so I had to use the calibrated wrist. A look up online of the bolt specs (all bolts on this tractor are marked 7 which I assume is about the equivalent of a grade 8.8) suggests 19ft-lbs for the 8mm bolts and 37 for the 10mms. This felt very light to me and I always prefer a little extra torque than too little as torque wrenches aren't a very accurate method of torque a bolt. On my wrench I exceeded these and went up to 25-30 on the 8s and 45 on the 10s.
The goobie is copper anti-seize. I went a little overboard with it here but it makes a nice rust preventative. All the holes in the block had corrosion in them. The bolts without lock tabs were given a dab of red loctite and the heads were then covered in anti-seize.
A little aside; Here are the fuel lines after a trip through the vat. They came out beautifully. After a day in the vat all the paint came off in sheets with a wire brush. I took a strand of copper wire and jammed in between the nut and nozzle to ensure conductivity.
They used to look like this. I figured I'd pull this plate off and run this through the derusting vat. I didn't realize the top of this plate is actually the injection pump casting. Should you remove it be very careful when you do, some of the shims can get stuck to both the block and pump and can get bent when removed. The shims control the timing of the injection which brings me to my next point.
I realized I forgot to mark the orientation of the flywheel and crankshaft when I first took it off. While should go on in any position without wobbling, assuming the bolt pattern line up, for the timing marks on the flywheel to be aligned it must be reinstalled in the original position. Here we see 1 | TC and 1 | FI which stand for cylinder 1 top dead center and fuel injection. The motor rotates counter clockwise viewed from the seat and fuel injection starts about 26° before TDC.
To correctly align the flywheel I first rotated the engine to TDC on the first cylinder. Which stroke it's on doesn't matter in this case but I set it to TDC on the compression stroke out of habit. When the first cylinder is at TDC 1 | TC should be visible in the timing inspection hole visible in the picture above.
Simply align the mark to roughly the 3 o'clock position and hump the flywheel up to the crankshaft. If I had to do this again I'd goto the autoparts store and get a M8x1.25 stud to help with alignment (actually I should've just cut the head off a bolt) but it's doable with just a flywheel bolt and some patience. If they flywheel gets stuck in the wrong position you should be able to wiggle it back off again. Once it's close enough to get a bolt started it should align itself the rest of the way as you thread the bolt in (don't force it if it doesn't want to go!).
