Mechanical Q for the smart guys???
 

This is a hydraulic oil pump from one of our skip loaders. It is the third to fail on two different tractors. Of course, you have to replace the entire pump - no sub parts available.

It mounts to the front of the crank. The spline only engages about half its length.

Pump is $1100!

Anyone have an idea on how to repair the spline? A welding technique? We are experimenting with drilling and inserting a pin/key - we've got nothing to lose on the old parts.

Any better ideas? Any help would be most appreciated.

Have pics of the splined shafts, and the failure?

Sorry - they didn't attach

http://forums.pelicanparts.com/uploa...1359411773.jpg

http://forums.pelicanparts.com/uploa...1359412025.jpg

http://forums.pelicanparts.com/uploa...1359412101.jpg

The pump is always engaged, and since it's pushing oil, I would not expect those splines to get a lot of hard impacts, but I don't know.

Are sure that is the correct pump? The splines should and need to fully engage.

nevermind... I was slow to post and photos are now up.

It appears the driving splines are worn out.

Or, have the female splines in the crank worn to a point that they are taking out the pumps male splines? Have any pictures of the crankshaft?

Paging Lubey....

:D

Seriously, though, I'm with URY914--if the splines aren't engaging fully then something is wrong.

yeah this for sure. If the splines in the crank are flogged out, it'll chew up any new shaft you put in there.

As to repairing the pump, you may be able to get a decent machine shop to make a new shaft for you. Hate to tell you though it'll probably cost as much as the replacement pump.

a good motor repair shop can cut off a shaft of a new motor and weld a splined shaft on..
Motor should have relatively cheap

We replace both male and female ends each time. Setup is from-the-factory oem.

Is that fretting due to a mis-alignment?

Install the parts together outside of the tractor. Is there wobble between the female and male parts? If there is are the parts in or out of spec/measurement?

Is the driver of the female part out of round? Can you manipulate the female side by hand when it is installed?

Mark the female side that points out to verify round. Manipulate the female part as it is installed. Verify that your female part moves in round.

Man, the places I could go with this post....nah, too easy. :D

Thanks for the input. For the record, these parts are failing in an as-installed-by-the-factory manner. There is A LOT of movement between the engine, the chassis and everything else due to the forces on this motor. All I can guess is that there has to be a little bit of play on that shaft due to expected movement. We keep replacing both the male and female but the time between failures is substantially less than all the other parts on the tractor. To me it is a design flaw, but what I need is way to fix what I've got.

make and model of the pump?

Thanks for your help Sammy. IDK but I will try to find out. It's oem on New Holland.

Are you saying the pump is hard mounted to the tractor while the engine is free to 'float' on its mounts?

It's trashed. I would be concerned the mating part is not taking fully advantage of the spline.

I'm surprised there isn't a replacement part for the shaft. I would explore that first.

Thank you. I have explore the options of. New shaft, but they only sell the whole pump. Since this is the oem configurations and since it has failed ontiple tractors, my question is, can u think of a way to fix the spline? Welding? Drilling a hole through it and bolting it?