JD 9300 backhoe control rework

[hetkind]

I am looking to rework the control levers of my JD 9300 backhoe attachment, currently mounted on a JD 450B shovel dozer. Hydraulic pump, main boom cylinder control valve and main boom cylinder have all been rebuilt or replaced with good components. I think I might not be getting full valve actuation due to extreme slop in the three main linkage elements, U101897, U11003 and T34282. To obtain two sets to rebuild the to main control levers is over $500 in parts. However, I can get all the pins and bushings I need via McMaster-Carr for about $25. Has anyone successfully drilled or reamed out the control elements, and put in oil impregnated bronze bushings? The job looks doable with a drill press and a shop press. And perhaps a straight reamer to the holes perfect!

 

[Delmer]

I've never put bronze bushings in something like this. I have drilled things out and added a bigger bolt to tighten them up. The bushing seems overkill to me, but why not?

The only thing to watch out for is if the holes are both wallowed in one direction, so that the worn hole doesn't center on the original hole. A die grinder or cape chisel would get you close enough to the original centering to be able to drill it out. Clutch and brake linkages have adjustment so that wear isn't as critical as a valve control, or maybe moving the linkage will just move the handle a bit, but still allow you more movement on the valve without the slop.

 

[hetkind]

I've never put bronze bushings in something like this. I have drilled things out and added a bigger bolt to tighten them up. The bushing seems overkill to me, but why not?

The only thing to watch out for is if the holes are both wallowed in one direction, so that the worn hole doesn't center on the original hole. A die grinder or cape chisel would get you close enough to the original centering to be able to drill it out. Clutch and brake linkages have adjustment so that wear isn't as critical as a valve control, or maybe moving the linkage will just move the handle a bit, but still allow you more movement on the valve without the slop.

Thanks for the response...I was thinking of drilling slightly undersized and using a long straight fluted reamer, then pressing the bushings in. This should help the wallow, and provide easy change bushing in the future.

 

[Willie B]

No bushings, but on a few controls I've drilled out, and inserted larger pins. On one JD 410 backhoe, I replaced the six section control valve with new other brand components. The new valves were too narrow, and joystick mechanism did not fit at all. I used structural steel to make a totally new joystick system. It worked better than original as everything was a bit shorter throw to function.
I began the process trying to expand the original cast iron base without success. Welding didn't prove as difficult as building up the holes, and drilling out.

 

[hetkind]

No bushings, but on a few controls I've drilled out, and inserted larger pins. On one JD 410 backhoe, I replaced the six section control valve with new other brand components. The new valves were too narrow, and joystick mechanism did not fit at all. I used structural steel to make a totally new joystick system. It worked better than original as everything was a bit shorter throw to function.
I began the process trying to expand the original cast iron base without success. Welding didn't prove as difficult as building up the holes, and drilling out.

I have thought about this option also...however, I can get the bronze, self lubricating bushings, ID 5/16 with OD 3/8 or 9/16 or 1/2 at basically a dollar an inch. This turns the repair from a field repair to a long term machine shop rework, and in a future date, easily replaceable pins and bushings should prevent this problem from reoccurring in the future. The tractor is working today, so maybe tonight it can come apart, for examination, measurement and ordering of pins, bushings and reamer.

 

[hetkind]

We had a break in the weather, and the controls came out, into the wash tank and then dissemble. I think Deere failed on the design of this one, steel pins in cast iron housings with no bushings and no easy way to lubricate. However, new pins, bushings, grips from McMaster-Carr should get this job done for under $100 while new parts from Deere start at over $1200.