Oil pump removal. Help!

It's been a long time since I have done anything like that but memory says probably jacking the engine up and possibly removing any cross members etc. Some are impossible. Please tell us more about why you are replacing the oil pump. There are a lot of things involved with low oil pressure. Things as simple as a bad sending unit or things as bad as bad crank bearings. I dont remember ever seeing just an oil pump fix an low pressure problem. It could help a worn engine but it never fixed bad bearings.

well, i'll take it for a drive and the oil pressure will stay at 10 while coasting then move to about 20 once I hit the gas. Eventually dropping to 0 later on during the drive with or without accelerating. It may move back up to 10-15 if I let it sit for 10 minutes.

I would pull the sending unit and put a mechanical gauge on it before tearing into it. Yes, it socks but it will tell you the true oil pressure. does it have any noises? Tapping, clicking, rattle at certain speeds or start up? Does it smoke at start up? I dont remember about Chrysler but I know Ford had rubber valve guide seals that would deteriorate and crumble. They would end up plugging the oil pump screen with little pieces. Some would partially plug the screen back under the slosh baffle on the pump where you couldn't see it. It didn't matter much at low rpm but when it was run at high speed or you stomped on it oil starvation would happen. If it has bad valve guide seals it will smoke on start up as oil has run down the stems into the cylinder at shut down. Next start up and that oil gets burned and results in a puff of blue.

I had an F250 that did it. It started developing a faint knock at start up and gradually got worse. I caught it early and rebuilt the heads and did an in chassis bearing replacement. Not my most professional rebuild but as I said, I caught it before it trashed the crank.

dodgedesertrunner wrote:
well, i'll take it for a drive and the oil pressure will stay at 10 while coasting then move to about 20 once I hit the gas. Eventually dropping to 0 later on during the drive with or without accelerating. It may move back up to 10-15 if I let it sit for 10 minutes.

What grade of oil does it have in it?What grade should it have?

I doubt if replacing the pump will solve the problem, they seldom fail unless oil changes were completely neglected which means much more serious issues.
If you do go ahead with it you will need to lift the engine to remove the pan, don't get carried away and damage the fan or tear hoses.While you are in there remove a rod cap and look at the bearing, I don't think you will like what you see.

I would check sending unit first. I find it hard to believe you can drive it after pressure drops to zero.

Bird Freak wrote:
I would check sending unit first. I find it hard to believe you can drive it after pressure drops to zero.

I would too. Usually with very low oil pressure the hydraulic lifters will clatter (if equipped) and possibly bearing noise. If you hear no unusual noises, a very good reason to confirm the oil gauge reading with a mechanical gauge.

It definitely doesn't make any abnormal sounds while running or starting up. it'll smoke a little bit once I start it up but will go away once I put the choke back in. I'll try the sending unit and throw a gauge on there to see if that helps.

Worn out main bearings will give the same symptoms. Been there, done that. I doubt it's the pump. As others have said, check the pressure with a reliable gauge.

What motor do you have in it???

the smallblocks {La 318, 340, 360} have internal oil pumps inside the pan.
The big blocks {B & RB 383, 400, 440} have a external pump, unbolts after you
remove the oil filter attached to it.