Hello, I'm replacing the rear main seal in my buddies 71 Maverick-it's a very leaking 302 engine. I'm trying to do it with the engine still in the car, I've seen a friend do this years ago by turning the crank by hand & slowly pushing the seal out with a screwdriver or welding rod or something-it is the 2piece style not the rope seal. I know that this will just buy the car a few thousand miles till it leaks again, but for now no $$$ to rebuild the 302. My big problem is I can't turn the motor over by hand, there is an aftermarket a/c pulley on the crank dampner & it has a hole in it that I can't get the large socket thru to attach onto the crank bolt to turn. Any other ideas on how to turn the motor over so I can try to push out this seal? Can I bump it with the solenoid-screwdriver method just a tad, or will this still be too much of a jump instead of a slow turn? Please let me know any ideas... Thanks
You might be able to pull the spark plugs so there is no compression working against you and just turn it by turning fan blade and holding belt tight, or possible use air nozzle in one of the spark plug holes.
I would definitely pull the plugs as suggested. A sneaky-pete is the tool to pull the seal out and over the top side of the crank. I'm pretty sure you are going to have to loosen the rear 4 main caps slightly and progressively (more in towards the back) to allow enough room to push the new seal in. I was able to pull mine out after dropping the crank slightly with long needle nose pliers. Make sure you retorque the main bolts properly
that doesnt work with ford bellhousings. they cover the flywheel ring gear teeth all the way around. unless he has the transmission out also.
If it still has the original rope seal in it...You will have trouble getting a new seal in there. The top half of the seal is retained in place with a small pin that sticks out of the block. You will need to remove the pin to get the new seal in place properly, if you go with a rubber one. If you use a rope seal you can istall it as described by dropping the crank a bit to gain clearance to get past the pin.
Pull plugs and use a starter button and just bump the starter with button at the same time push the seal out
Well-I didn't get to the seal yesterday, spend most of the afternoon cleaning & scraping the pan gasket off. I think I'm just going to remove that a/c pulley, I also have a radiator leak & that needs to come out. I will remove all the plugs too & loosen all the main caps. Oh, what is a sneaky pete? Thanks to all who replied...
When you get around to the seal, think about what caused the seal to go bad. The part that supports the crank in the center of the seal is the rear main bearing. You might want to replace it to ensure the crank is kept centered.
Well I still didn't get to the seal, I had to take out the radiator yesterday(new one went bad). Today I sure hope to, I'm home today w/a sick kid. I did notice that the bearing half on the main cap is worn, very badly actually. I see a lot of copper on it. The motor was rebuilt in the 70's I was told & it has .040 pistons in it now. (We had the heads off awhile back). So you are saying I can just replace the lower bearing half in each of the mains? I can do that(never had), but do I get std bearings, oversize or undersize??? Doesn't the sizing come into play then? It sure could use a rebuild, but it is very strong right now(all cyl have 140 compression, & new guides were done). I did check all the other mains too & they are all worn the same-a lot of copper showing.
If they are worn and you're in there, I'd replace them. Rod brgs too. The cheap route would be to figure out what was in there (if oversized) and look at the journals on the crank. If they're scored, you really need a bottom end build. If they're not too bad and you just need it back together, put new bearings (upper and lower) in and hope for the best. To replace the upper, push on the side without the tab and turn the crank, it should roll out. If you see solid copper, it sounds to me like its worn out or they were fit too tight to begin with. Did it have any noise from the bottom end before you took it apart? Check the thrust bearing too.
