TIme to replace the timing cover??

401 timing cover. I measured the oil pump clearance and the oil pump stickout and it was OK. Not great but at the top end of specs from what I can tell.

Other than that, what else do I need to measure? I'd just replace it but I understand the new covers are all made by Crown and the quality is just not that great. Some of the new one's are susposed to be out of tolerance at the oil pump from the factory. SO I want to keep the old one if I can.

Other than the pump rebuild kit and midplate kit from Bulltear, any suggestions?

 

check the clearance between the gears and the inside of the cavity. If that's out of spec then no go.

 

Obiwan has a good discussion: http://www.jedi.com/obiwan/jeep/wagoneer/401/timingcover.html

He claims that the side clearance is not as critical and the end clearance. You can lap the timing cover face to reduce end play. You can also go with a thinner gasket. Bull Tear sells the thinner gaskets.

It seems rather common that owners throw parts at these engines when they have low OP. Usually they will install a midplate and new pump gears, apparently without measuring. I also hear that, if you measure the oil pump and it's ok, and the rod and main bearings measure ok (more Plastigage!), then you have to suspect the cam bearings. Cam bearing failure seems fairly common for these engines. Can't fault them too much though, given their age.

Unfortunately (fortunately for me) I don't have a lot of experience with manipulating the oil pumps on these engines, even though I've owned a few of them. All the ones I own(ed) have good oil pressure - knock on wood! So I'm just repeating what I've read and learned.

 

Thanks Tim. It's going in for a complete rebuild. New cam, rings, bearings, etc. I'd just replace the timing cover but the jedi article you referenced (the one I was using by the way) made me think it was better to use the old one than buy a new one if i could.

Want to make sure the motor lives a long and happy life........