A Picture of my woes

One more time guys? I can see a vertical groove in there. Is this where the pin should ride?

Allan

I know nothing about the groove and pin, but the Idea I shared for plugging the hole could be adapted to have a pin in a groove. if a stiffer bushing is used and a hardened pin (tapered pin might be best)swells it and ends up in the groove.
Jim

The groove you see is in the tappet, designed to keep it square with the cam shaft in the pump. The missing pin is a press fit in the pump housing. I do not think that there is any seal other than the fit of the pin in the housing.

Without the guide pin the tappet is going to turn slightly which can cause timing to advance a little, but more important will be the roller under the tappet will contact the cam on one end instead of full contact over the total length. If run long enough without the pin it will damage the cam,roller, and tappet.

Is that an updated model over the one listed on CaseIH's site? I was going to poke around for a part number for you & can't seem to find a plug, pin or hole in that spot on the diagram. Maybe I've been looking at the old tractors too long?

Mike

I'm fired. I just checked your post to pete23 & seen you had seen what I just seen, see? Sorry, not so sharp today. I have to head into the dealership tomorrow & will see if they have a spare. *sigh*

Mike

Owen,

So that tappet thing isn't suppost to turn then? It's not 'spinning'? It just needs to be held stationary by the pin?

Gotta figure out how to anchor it until I can turn loose of the tractor for proper repair after this season.

Thanks for your help,

Allan

There is just a straight roller that fits in the bottom of the tappet and rides on the cam. The guide pin is there to keep the tappet from turning so the roller has full contact with the cam. The push rod that sits on the top of the cam is actually the high pressure pump plunger/piston and is turning at 1/2 engine speed. There is a convex button between the tappet and the plunger that serves to insure that there are not any side forces transmitted to the pump head and also by varying the thickness serves as a way to adjust the internal timing. Because the plunger is turning there is some rotational force transmitted back down to the plunger. This may tend to cause the roller to not stay parallel with the cam. But like Pete posted earlier, if you did nothing but seal up the hole it may outlast all of us!

I don't have any old housing laying around here or I would send you a pin. Usually have to change the housing when the head gets loose and causes wear. Too much wear and they won't stay tight and the lower seal will leak fuel into the oil.

If when you have pump problems you are just going to exchange pumps I would probably just seal it up and see what happens. If it does take the cam and roller out you will notice a loss of power since the plunger will move up a little late retarding the timing and when you lose stroke you will get less fuel delivery.

Okay, thanks you guys!

I'm gonna take all your information, meld it with Jim's idea and see if I can construct some sort of a stopgap to at least get me thru the summer.

Allan

I'm gonna try it, Jim.

Thanks for your help.

Allan