Oil pump question.

[Full Size Jeeper]

Looked at a few of the oil pump rebuild threads and have a few questions. First off, I think this engine Had new bearings installed around 2002. Bearings have a date stamp. One of the piston tops was a banged up, like maybe it dropped a valve, but all cylinders were standard. Pump has a mid plate and it is worn.Do I need it and can I just clean it up using the glass and valve grinding compound. Also lots of small groves in the side of the pump gear housing. Is any amount okay, how much is to much. I will post a few pics.

[Full Size Jeeper]

Mid plate

[Ristow]

pretty much normal wear on the pump. what a miserable design.


on the midplate,no you don't. all that midplate does is add another spot to leak oil.


it ranks up there with the oil line mod.


and did somebody use silicone on those gaskets?

[440sixpack]

I've seen worse. whatever you do don't try to smooth it up all that does is increase the tolerances.

The mid plate can be replaced, or don't use it if your adapter plate is in good shape.


Hard tell how bad your cover is by a picture but if it's decent I'd rather use it than a Chinese reproduction.

[Full Size Jeeper]

Thanks for the reply's. I will skip the mid plate, some sort of sealer was used on the gasket. I will check the clearance and ask a few more question later. Also had no oil pressure problems the year and a half I drove it.

[Ristow]

never silicone. i use aerosol copper coat there if at all.

[Full Size Jeeper]

Okay, worked on the oil pump end cover, used a piece of glass and valve lapping compound.

[Full Size Jeeper]

Took about an hour and a half to get it good enough for me.

[Full Size Jeeper]

Before.

[Full Size Jeeper]

After.

[Full Size Jeeper]

Here is the plastigage. Drive gear is at .006

[Full Size Jeeper]

Driven gear is at .004

[Full Size Jeeper]

So to my thinking, the timing cover mating surface is not flat or the top surface where the gears sit is worn, the drive gear side is more worn than the driven gear side by .002. Also the gears to cover has some grooving, but the thickest feeler gauge I can insert is .003 on either side. So with that said, do I have A usable cover? Thanks in advance.

[Full Size Jeeper]

So, should I lap the timing cover side to try and tighten up the clearance a little. The TSM say 2 to 8 thousands is spec, but .002 is preferred. Also I will never be able to get rid of the .002 difference between the gears.

[Ristow]

lap the cover till the tolerance is nil,but the gears turn freely. it will increase as it heats up. i just do mine feel. if it's off the engine,yes i would work till i can;t feel any clearance but the gears turn freely.