YET Another Driveline Question

[Sam Mac]

The OP is talking about the short shaft that runs from the back side of the pump to the rear PTO, not the main drive shaft. To the best of my knowledge Oak has more info on this area. I'll PM him to check in on this one.

[FrankF3]

Jonathan, I converted it about 2 - 3 years ago to run CV joints, but it had problems with that rear PTO shaft a couple of years before I did that. Space is pretty limited between the backside of the pump and to where the clutch is situated. I was thinking about a harmonic balancer too, but there's no room in there. Don't forget to take the rock shaft and the fuel tank into account too.

[CubDieselFan]

Originally Posted by Sam Mac

The OP is talking about the short shaft that runs from the back side of the pump to the rear PTO, not the main drive shaft. To the best of my knowledge Oak has more info on this area. I'll PM him to check in on this one.

10-4, I did not catch that.

[Oak]

It's a poor design in my opinion. Too many pieces are in the shaft and are pinned together. Here are the pieces just to make the short shaft from the rear of the hydro to the bearing assembly that the pto is mounted to.
DSCN1131.jpg

Here is what the shaft looks like. The pins wear the couplers so that the holes get egg shaped and then the shaft hole gets worn and the pin gets loose and the safety wire is the only thing holding it in place.
DSCN1121.jpg

I have purchased all new couplers from Surplus Center but the one that attaches to the rear of the hydro is splined on one end and needs the other side machined out for the short shaft. I have talked to Jeff about this a year or so ago but never went any further.
DSCN1145.jpg DSCN1146.jpg

I often wondered why the shafts couldn't be welded or at least leave on pin in just incase you hit something and needed a shear pin

[J-Mech]

You don't need a shear pin.

I'd just weld that shaft together. That would help.

[Jeff in Pa]

Originally Posted by J-Mech

You don't need a shear pin.

I'd just weld that shaft together. That would help.

Would this work?

If I have this correct, a single spirol pin hole on the pump side. That coupler on the pump side and a splined coupler on the opposite end. Both couplers welded to shaft. The spirol pin would be the "weak link" or consumable part.

What do you think?

[J-Mech]

That's what I would do Jeff.

Only thing that would be better is if it was splined on the pump end.

[Jeff in Pa]

Originally Posted by J-Mech

That's what I would do Jeff.

Only thing that would be better is if it was splined on the pump end.

Thanks Jon

While splined on the pump end could be good, I think you do need a weak link to protect expensive parts.

[Terry C]

If I was going to build one for myself I would figure out a way to have a cv or a love-joy device by the pump for misalignment issues. Frame twisting and such would be hard on that pump I would think. But I worry about things maybe too much.