Massey 44 oil pump

[mark49]

Has anyone here ever rebuilt an oil pump on a 44 (or 55). I have the pieces to do so, but can't figure out how to get the gears off of the shaft.

 

[DWF]

One gear should have a snap ring holding it on a shaft with woodruff keys. The other gear just turns on another shat, no snap ring on thatone.
DWF

 

[mark49]

I got the bottom gear right out. I see the snap ring in my I&T, but no sign of it on the shaft.

 

[mark49]

After digging the dirt away, I can see the snap ring inside of the pump gear. So it appears that the drive gear must come off first- and it is ON there!! Thinking of throwing it in the deep freeze and then heating the gear with a torch while I have a puller on it.

 

[used red MN]

I would say it is possible the drive gear is not really meant to be removed from the shaft since it shows no retaining method for it. It is very likely a real tight press fit. Driving the shaft out of the pump gear is probably the correct way. Probably want to use a brass drift. At some point the woodruff key will hit the case so something will have to be placed under the gear to hold it up away from the case, washers or nuts may work. Place one across from the other to support it evenly. Here is the diagram I went by. It looks like a diesel is nearly the same pump. AGCO MH44 parts diagram

 

[mark49]

That is the same diagram that I&T has. I have a pump that was locked up that I tried to get apart a few years back that I smooshed teeth off of with a puller. Never did get the gear off. Not much room between the gear and pump body.

 

[used red MN]

That is the same diagram that I&T has. I have a pump that was locked up that I tried to get apart a few years back that I smooshed teeth off of with a puller. Never did get the gear off. Not much room between the gear and pump body.

Just to be clear I am talking about removing the “pumping” gear number 9 from the shaft. I am going to make a huge guesstimation that the woodruff key is centered in the gear when assembled. Measure down to the key from the outside. This will be the amount it can be moved before it interferes with the case. Supporting the pump solidly on the three ears of the T around the gear will help, an anvil would be an example of something solid. Forget that freezer idea, waste of time that is only of value when the parts are separated for assembly. Also believe it or not the casting (all metal) becomes more brittle when you start getting to temps below zero. Look up brittle fracture.