1F oil pump rebuild? What to do here, need advice (1 Viewer)

[Spring Grover]

Hey all. Recently set a 1F engine in a truck I'm building, just a roller right now, no tub. Next is trans and t-case, but before, I lubed up the cylinders with wd and primed the oil system as there's much turning of the engine for the clutch. I got my drill in the oil pump slot through the distributor port, spinning, great oil pressure, but making a noise I haven't heard before, sounded like a mason drill. I double checked the drill, tried another drill, and same. After research, concluded the oil pump has issues. Pulled the motor, flipped it, pulled the pump out. Pulled pump cover and sure enough, the driven gear was making contact with the pump cover, see pic. I've gone through all the steps per the fsm in checking tolerances and this pump checks out, like new. My only guess is that the gasket wore out which caused the tolerance to close, and the gear starts rubbing the cover?
I thought if I tossed a new gasket in, try it again. No gasket out there to be found. Make a gasket? Would need to be pretty thin.
My options as I see it:
1). Source a new/used pump
2). Source a new used pump
Am I wrong, or is there parts out there?
I found a new pump from JoeTLC.com, looks right. Either way, I need a working oil pump.
Thoughts?

 

[Spring Grover]

Forgot a couple pics

 

[DesertFJ40]

Was there a paper gasket? You can always just buy a sheet synthetic paper gasket thats really thin and make a new one. An easy way to do it is lay the paper gasket on it, take a ball peen hammer, and make light taps around the edges of the oil pump. It will slowly make the cuts on the paper material and you'll soon have a perfectly fitting gasket.

Other than that, I didn't know they had a gasket to begin with. I forget what the correct thickness is for the paper gaskets. I'd assume it's the same thickness used for the transmisson and transfer case gaskets. Those are really thin.

 

[pb4ugo]

I've not messed with the Toyota pump, but in my experience with other pumps, the gears make contact with the bottom plate by gravity. The manual doesn't mention a gasket. It says " straight edge, and the gear contacting surface" The distributor doesn't put pressure on the pumps driveshaft.

 

[Pighead]

That doesn't look too bad, flip the other gear and drive it.
I think there's a feeler gauge check listed in the FSM, maybe try that too.

 

[charliemeyer007]

How hard are up pressing down with the drill. +1 for peen hammer gasket cutting. Brass shim stock cut to fit with Aviation Permatex on both sides makes for a thin gasket. Are you sure there is a gasket? $OR has rebuilt pumps $625 ( get $300 back with a good core)

 

[pb4ugo]

I think if you add a gasket the tolerances will be out of spec. and will reduce pump output.

 

[igotta40]

New oil pump = peace of mind

 

[Spring Grover]

There is indeed a gasket in between the cases. It was damaged when I split it, figured I'd simply replace. With no gasket, both gears hit the cover, and if you tighten the screws, they will lock up against the cover. The gasket needs to be a very specific thickness, which Idk what it is. If you put the cases together with no gasket, like it is now, It's probably about a .010 gap, I didn't measure it, but I could, base a gasket material off of that.
I just wondered if someone has successfully done this, and what material they used.

How hard are up pressing down with the drill.

You know, looking again at it, it was the drive gear that hit the case. Enough down pressure would probably cause this to happen. A real good question. My answer, I pushed no harder than any other time? I've used the drill quite a few times, never had one make this growling noise.

 

[charliemeyer007]

Just a thought here. That's a helical gear and it produces thrust when driven. The driving tab from the dizzy free floats in the oil drive shaft. I suspect the gears in the pump produces some sort of thrust or at least the bypass flow keeps the gears centered - I guess I'm saying pressing down on the oil drive shaft and at low rpm isn't the same forces as when driven by the dizzy.

 

[73FJ40]

Just a thought here. That's a helical gear and it produces thrust when driven. The driving tab from the dizzy free floats in the oil drive shaft. I suspect the gears in the pump produces some sort of thrust or at least the bypass flow keeps the gears centered - I guess I'm saying pressing down on the oil drive shaft and at low rpm isn't the same forces as when driven by the dizzy.

define "helical"? I was under the impression the F engine oil pump had spur gears.

 

[charliemeyer007]

The gear on the cam is heliacal/worm- drives the dizzy which drives the oil pump. Oil pump gears are spur - nothing is perfect so I'm sure there is some thrust - again bypass oil pressure leakage if you will might center the gears.