WD45 Oil Pump

Got around to cleaning the oil pump for the WD45 engine build but noticed something. This pump has a internal relief valve. Is this from a D17?

Little back story. I bought a complete WD45 engine from my cousin supposedly ran fine 10yrs ago to rebuild. Tore it down and block was cracked. I got another block now. I just went and looked at the first block and it didn't have any modifications. There was a nut behind the relief valve in side of engine like they tried to make it stay closed or something. So I guess I need to find a WD45 oil pump to make this right.

No need to find a different oil pump.   When they switched over to the full flow pump, Allis basically discontinued servicing or providing the old style pump in the parts department and said to use the newer pump with the built in relief valve in the older engines.  Just need to change over the pump drive gear to match the camshaft.  Id you look at AGCO parts book, you will see that the part number for a complete pump is the same from a WC through a 175...but you have to order the gear separately.

The guys are spot on, you have the up-dated pump. the spring rides on the end plate with the plunger below the spring in the pump housing, lots of WC/WD/WD45 engines had and some still do have a nut or washers behind the plug holding the spring in. I plane the end cap back flat and note the gasket go's around the spring so the oil can come out with out blowing the gasket out. if you look at you pic on the side of the pump housing below the spring you can see the relief valve drain hole. the plunger is just below that hole. If you make the cover gasket use the same thickens gasket as the old one. I true the cover before installing it. bend one of the four tabs on the intake sump and slide it sideways off the intake then clean the screen on both sides of it.

I don't know what the tolerances were for an Allis oil pump, but .006 seems like a lot to me. I also don't know where you get .011 "between gears". Are you talking backlash?
Have a look at this video if you want to tighten up your oil pump.

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Edited by CTuckerNWIL - 14 Aug 2016 at 10:08am

Gear on cam and pump look good. The relief valve is out of block. One in pump is currently stuck. I'll get a pic of it a little later today.
Book says .008 max between body and gears. I have .006 It says .015 max backlash I have .011

Edited by 79fordblake - 14 Aug 2016 at 10:43am

I have the Agco book and IT book. On the body to gear spec it's close to the max which worrys me on about a $4500 engine. Here is pics of the gears. It's kind of a toss up for me. Anything close to out of spec I have been throwing it away or fixing it. I still have to get a better crank as well. The one I have is .020 on mains and .010 on rods already. It would work but with the theme I've been going with its not good enough...lol.

Yeah I was wondering if any new parts for the pump are available. I think I have also decided to make it full flow oiling......it just keeps snowballing LOL!
The crank looks pretty good but does have some scratches...probably would need to be turned again. Would like to find one that is standard with minor flaws that would clean up at .010
Tractor disease is a horrible condition....everybody at work thinks I'm crazy....lol. :)