Oil Pump LB7 vs LMM

[durallymax]

Part numbers are different, but through reading around I get some conflicting info. they use the same drive gear this I can tell. Do not have the pump out yet to compare it, just curious before everybody is sleeping if there is any reason an LB7 pump cannot be used on an LMM?

Fighting a gear noise that goes away with oil pump gear removed. New oil pump gear did not fix issue, going to try the gear on crank but not convinced. Oil pump still makes 60psi at idle. It was on truck with broken crank though and bearing material in suction screen.

Thanks.

 

[Harbin_22]

Not sure about internal difference but the LMM has a reverse thread shaft for the gear and the lb7 has a regular thread. May be why them part numbers are different

 

[durallymax]

Not sure about internal difference but the LMM has a reverse thread shaft for the gear and the lb7 has a regular thread. May be why them part numbers are different

I remembered the different thread part, never made the connection for the part number though lol. Thanks. Got the motor out again so I'll pull both pumps apart and compare.

 

[durallymax]

Can't see any reason this pump would be making noise. Thought maybe the gear on crank wasn't tracking straight as I just had it keyed but measuring face of gear to face of crank snout it was within a couple thousanths all the way around. Still thinking that gear itself must have some funky wear on it from the broken crank that's making my noise. Can't see any odd scuffing or anything though. Going to replace it anyways though with another one I have here. I'm assuming the two holes in that gear are for the knock pins to align the reluctor?

Hate to go through the work of stripping the LB7 I have sitting here for its oil pump but I also don't want to put this one back in and find out its the issue. Never heard of one going bad and dont know what would cause it. The pump was aligned on the dowels. The noise will take a few seconds to show up if I let it sit for awhile. Kind of seems like it doesn't show up until pump is under load.


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[Fahlin Racing]

Tear down time. You don't happen to have any pics of the internals do you? This is one part I am sure not many look for stress relief.

 

[skintback]

I have seen cheap water pumps make a loud gear noise

 

[delong_1]

I have seen cheap water pumps make a loud gear noise

been there...

 

[durallymax]

I have seen cheap water pumps make a loud gear noise

Ran into that many times. Not the case with this one, noise there with water pump removed. Gone with oil pump gear removed. New oil pump gear did not fix it. Replaced oil pump and crank side gear and motor is back in truck. Been busy with 2nd crop hay but going to get it running again this weekend.