I have a 390/Hydramatic (1960 Jetaway) with a rear engine seal leak. I was told that it can be replaced with the engine in the car, by loosening the main caps And removing the offending rear cap, and working the seal Around the groove. Does this mean the flex plate hAs to be disconnected from the torque converter, so thAt the crank can move down a bit? Anyone done this successfully, with the engine in the car? I know normally you would pull the engine, but I have a space problem (don,t we all?) and have no floor spAce for this.
It can be done. "Lisle" sells an inexpensive tool to do this. Still "no piece of cake" but you can do it. Edit, looked on line, tool no longer available. If you have access to an older "Motors" manual it will show a procedure for change out.
I have done it to a 389 Pontiac, just as you described. The tool looks like a Chinese finger trap, and is slid over the crank after the old seal is removed. Then it grabs the new seal and it is pulled over the top of the crank while turning the crank. Hope that makes sense. Look in old Motors Manual for pictures of the whole deal.
You need the flex plate or flywheel in place because you stick another piece of the tool (a small aluminum piece) in the oil hole in the crank and then turn the engine with the flex plate to push the seal out. Some kits have a screw setup that you screw into the end of the seal and pull it out but I'll guarantee the neighborhood has a serious chance of learning your complete profanity vocabulary when you use one of those. Actually a bit of both and a helper to turn the crank or pull on the screw setup works reasonably well. It's a good time to take a look at the other bearing too as you may decide to replace them when you have it that far apart if they look suspect.
and if the timing chain is loose you may want to replace that....and how do the cam lobes look? A little worn?....that was my story once, damn good running engine , leaking rear main seal...ended up rebuilding the entire engine!
The Jalopy Journal
