Engine/Transmission (1994 - 1998) Stopping oil leaks

[GJolicoeur]

I've done a lot of work in the last month to stop oil leaks. I replaced the rear gear case gasket, and redid the front gasket with Permatex. I rebuilt the vacuum pump to stop leaks there and put in a O-ring on the timing pin and replaced the gasket between it and the housing.



I rebuilt the NV4500 (new bearings & synchros), replaced and renewed all the seals there especially the one between the transmission and the transfer case.



I still have small leaks at some of the lowest bolts in the gear case (appears to be weeping around the threads) and 3 or 4 pan bolts near the front of the engine.



Whenever I used the Permatex, I was careful to go around each bolt hole to make sure oil couldn't get at them. I know that some of them are drilled through and oil can get down the threads.



I pulled a couple of the pan bolts and cleaned them, used the Permatex on them and reseated them.



They are still leaking.



Any ideas?

 

[Joe G.]

I assume you have a 12 valve since you have posted on this forum. The most persistant oil leaks I have had turned out to be valve cover gaskets. #5 and #6 are especially hard to see and hard to stop leaking. Oil runs down the block in hard to see places and drips off pan screws and the bell housing.