How about drilling the coupler and the shaft and using a shear bolt.

Based on the pictures,
there is too much shaft misalignment,
does the pump have any alignment collars that hold it centered?
For the splines to wear like that something is moving off center or the shafts are not concentric,
not to mention the connection looks like it has not had enough lubricant

Really need pictures of the other part that this pump connects too.
I wonder if the pump shaft could be turned down some then a nut fitted and welded to the shaft then weld a thick wall 6 sided socket to the other side,
then add a good helping of moly grease to the connection

Have you brought up the issue with New Holland. Something is wrong if you are going thru that many motors.

What does the mating part look like?
How long is the internal spine on the mating part?

One more question: Can you take apart the pump and remove the shaft.

(other than engagement..)
Could the crank bearings be worn or flexing under load?
Could there be fluid blockage or undersized hoses, creating too much load?

What the psi?
Who's the manufacturer?
Do you know for sure that you are not getting air in the system?

I think Scott asked the right question. If the pump is mounted to the chassis then the engine must be rigidly mounted too. If the engine can move the pump must be bolted to it and not to the chassis.

regards,
Phil

The pump is registered for alignment. As long as the fit and surfaces are good, alignment should be good.
The amount of engagement is adequate: 1 times diameter is OK, 1 1/2 times is optimal.

If it was put together dry, duh.
if it was put together with good ole EP grease, that's bad 2. The oil will quickly separate from the binder and cause that kind of wear.
We use spline lube from sundyne on the only spline drives we still run, works well.

http://www.corrosion-products.com/CPE/GE%20Web%20Site/API%20Sundyne/lmv_313_iom.pdf

Iffn it gets packed with mud all bets are off, we'd have to seal it with o-rings. Yes, it can be done.
The spline is heat treated and slightly annealed, weldings not an option.

If we can ID the pump, I know a guy at Kaman industrial supply that can probably track it down and get parts from the real OEM and save $$$$ He's been doing it for a really long time and is one of the best.
I spent a whole bunch of years as a pump reliability engineer. Now I just run the daycare center.

BTW I'm better the female spline drive is shot too based on the wear.

As questioned, if the pump is solid and the engine floats, even a small amount you will never fix the issue. The vibration of the engine will wear the splines out no matter what. Some possible fixes:

- float the pump
- what is behind that flat surface around where the shaft comes out of the pump? Can it be machined off to give additional spline engagement?
- What lube and how often is it lubed? I would grease it every couple hours with moly.
- Solid engine mounts to make alignment more accurate.

I know abolutely nothing about it. But looking just from the picture, it looks like the wear at the center & left side of the spline is more than the right. It also looks like the grooves are worn in a dish shaped contour. If that's the case, it might be an alignment problem. That doesn't look likely, since it looks like the pump collar seats into a recess and gets bolted down. I doubt New Holland would make a design mistake like making the engine mounts able to move while the pump base doesn't follow along. Have you tried something like putting some colored material on a new set of splines & inserting it & withdrawing it to look for a pattern? Just a rookie comment.

What about manufacturing a new shaft of better material and taking in cores from other people and rebuilding them with YOUR improved shafts for a profit.

I believe its an alignment problem or the fact that the motor and engine are not as one unit.
I don't know if this will help or not but what is your standby pressure? Thats the presurre that flows through the pump at all times, most of these are constant displacement pumps - if its spinning its pumping. If your system puts out 1000 psi and your standby is 200 psi there is a big shock when you use that curcuit, try a higher standby pressure to soften the shock of starting when you use that curcuit. There should also be a relief valve in the system that will bleed a bit of pressure from your system as your cylinder reaches it max extension, you might want to up that pressure relief. I'm not an expert, just around it all the time and learned a bit from the experts, unfortunatly I only learned enough to make me dangerous.
Finn

My guess - the bearings are worn in the shaft with the female splines, causing misalignment.

+1 with wdfifteen.

I agree with what has been said above. However, IF the pump and the engine are ridgid, the wear is unexpected for me. I think the above nails it.

IF this is not the case or you can't fix the crank wobble. Here is a thought.

Something that you could try however is to buy a male spline in SOFTER material than the female and attach to the pump. You would have to cut the pump's shaft back to allow for this. The softer spline would be sacrificial. You would need to replace / maintain it more often but it would be the planned point of failure.

Great question.

Larry

Thanks for all the great info.



The motor is hard mounted to a bracket off the chassis, on this model and the older ones too. This piece (currently being drilled) is what attaches to the crank - I did a bit more research and learned that every model previous to this one has a grease fitting. Why they left it off this one is anyone's guess.:

http://forums.pelicanparts.com/uploa...1359484602.jpg

http://forums.pelicanparts.com/uploa...1359484643.jpg

Pump info:

http://forums.pelicanparts.com/uploa...1359484747.jpg

At this point we have not gone inside the pump as we can't get a new shaft.

With respect to alignment, there is no adjustment. However, I know the motor moves about when under load.

LOL that looks like the front driveshaft from an AWD BMW
They do precisely the same thing-- except while you are driving

David
Can you get a shot of the actual front of the crank too?
It doesn't look like there's much in the way of alignment going on from what you've posted.
I was expecting to see a female portion where the flange would index the pump to the part that the splines would be coming out of. Kind of like a hub centric wheel indexing.

New motor mounts?
Put it under load and measure how much it shifts.
That doesn't seem right. Fixed pump with floating engine? Seem they should have stuck a u-joint in there.

s_morrison57 mentions hydraulic shock/kickback.
Is there some kind of a anti-hammer valve product to reduce this?

I was playing with a friend's newer Kubota backhoe, which was kicking and jerking.
Turned out one of the return recirculation hoses was kinked and made the hydraulics funky.
Smoothed out after an external collar straitened it.