Gentlemen, I have searched this forum high and low for some advice and tips and found a number that were either unanswered or the topic went off into a tangent.
I'm about to embark on a trepadicious journey of installing new main cap seals on my 302, without taking the motor or the crank out. I have the Haynes manual and the original Ford workshop manual and both say it can be done...BUT...they omitted a couple of things that I'm not about to find out by error.
Sure, I removed the transmission (in favor of a clutch overhaul), the oilpan, but then it occured to me, if I was to loosen the main cap bolts to enable me to remove the offending seal, does this mean:
That I need to remove the waterpump, the timing cover, the timing gear set, as this would hold the crank down? Or would it be safe to let the crank drop by no less that the specified 1/32" and not damage the front oil seal and timing set?
Once the seal is in and the re-assembly starts, do I need to pay special attention to the connecting rod spacing with a feeler-gauge again?
There used to be a company that sold a mesh tube device, commonly referred to as a "Chinese Finger Trap", that was designed to draw in the new half-seal without damaging it once you removed the old one. You load the new half-seal into the mesh tube, pull both ends of the tube so it tightens around the seal, and thread one end of the tube through the groove in the block. Then you can pull the new seal through by keeping the tube tight. When it's in, you release the back end of the tube, and you can pull it off of the seal, and you can make final adjustments to its position.
I didn't use this device, as I was able to lube up both the new seal and the groove enough to push the seal in by hand.
If your engine is newer than 1982, it has the one-piece seal, and you can change it without dropping the oil pan or rear main bearing. But you do have to get the transmission out of the way, which apparently you already have. You basically destroy the old seal by screwing coarse thread screws into it and pulling it out.
If you had to loosen the other crank bolts to slightly drop the crank shaft, there's probably enough slop in the timing chain that it will not interfere with the small amount that you have to drop the crank.
As for tightening the bearings back, the only one you have to be careful is the rear main cap, as that's the only one you have to remove, and the rest were loosened but left in-place. Make sure that it is properly lined up when you install it. Again, this would be for the two-piece rear main seal.