Installing a lovejoy coupler

[reaperman]

I should be getting a new hydro pump tomorrow via ups for my log splitter. The existing or old pump on the splitter puked out after only 3 years of home use. I took the splitter to a shop to see why the cycle time went from 13 to 23 seconds. He said he had troubles finding the problem since the pump was reading full pressure from his gauges. But later found shavings in the hydro tank so he took the pump apart. He found the gears on the 11gpm Haldex, closest to the output shaft, somehow got pushed backwards into the housing. Causing the gears to rub against the back plate and wearing into that piece of metal, causing the shavings etc. And I suppose somehow is slowing the splitters cycle time down.

One question is how could the gears be pushed backwards into the housing? There is a mounting bracket between the splitter and the engine that should keep the distance between the pump and the motor consistent. Even if the coupling slid backwards, I think it would only slide on the shaft and not push on the gears.

Anyway, being a new pump is coming tomorrow I want to make sure its mounted correctly. Is there some magic distance the couplings need to be? I know the set screw on the coupling for the pump output shaft had to be screwed tight on the woodruff key. And I'd think as long as that coupling is correct, the star shaped rubber washer and the coupling on the engine should be slid tight against the coupling on the pumps shaft. Then bolt the bracket to the motor and hydro pump and I should be splitting again, right?

 

[OH_Varmntr]

I'm a maintenance man at a factory and deal with couplings day in and day out.

You don't want to compress the elastomer cushion, as you can apply axial pressure on the shafts and wear out bearings, bushings and other vital components. I don't have a measurement, as I always "eyeball" it but if I had to guess I'd say to keep the ends of the jaws about 1/8" away from each other.

As far as how the shaft can be pushed backwards to wear the gears out, it seems from everything I've read, these newer pumps just don't last as long as they used to. Guys buying the $300+ pumps are getting the same longevity from the cheaper $180-$200 pumps.

It's not always about axial forces of the shafts from the drivetrain, but it also depends on the output or pressure port locations inside the pump that can cause axial and radial forces on the shafts and gears.

So basically it's hard telling exactly what caused yours to wear out.