I'm sure some of you know more about Wabco graders than I do so I'd like to ask a question. I have a Wabco 555 that is new to me. The only issues are a loose steering arm that goes into the king pin and loose lift arms on the blade lift gearbox shafts. I will see what can be done about the loose steering when I get around to it but I'd like to know what keeps the arm from turning on the lift shaft. Is there a key in there? I can't see any from the parts book diagram. Some previous owner has welded a big round plate on the end of the shafts to keep the arms from sliding off. I will grind/drilll the welds out and then should be able to slip the arms off. I can add some relief to the arms by cutting the slot larger so the arm can tighten more. If there is a key and the keyways are shot then it would take a little time and money to remove the shafts to get a new keyways cut and new keyways broached in the arms. This might sound like a dumb idea but I was wondering if drilling a hole parallel to the main axis of the shaft that would be half on the shaft and half on the arm and using a piece of drill rod for a key. This could be done with the arms tightened in place. It is just for farm use so I don't feel like spending half of what I paid for the grader to tighten up the arms. Any thoughts?
my 550 has a key arrangement, so it will probrarily be the same, the fix you suggest sounds good to me, if that doesnt work, you could arc it on with low hydrogen rods,just use as many amps as you can!!! let us know how you go, goodwin
Those shafts have splines. Big ones.
Thanks Goodwin and Ledsel. Now that I look at the parts book more closely, I think Ledsel is right, and that means I have a much more difficult fix. Opening up the slot will let me tighten it up some but that isn't going to get rid of all the play. Maybe there's a 90,000 psi industrial strength JB Weld.....Ha!
From my experience as a Wabco 440H operator/mechanic, another place where you can get rid of a little looseness in your blade lift, is by marking the big splined shaft in 3 places, 120 degrees apart, starting with #1 at the slot in the arm. With proper pulling, lifting, and support equipment, remove the arm, fire up the machine, and rotate the splined shaft 120 degrees. This will put the worm gear in an area that should have less wear (in your normal blading positions) and should make your machine easier to control. There may also be shims, setscrews, locknuts, etc, that can be adjusted on the gearboxes to tighten things up. This can also be done on the circle sideshift gearbox too. I hope this info is still good, it has been almost 30 years since I tackled this job. Good luck with your repairs. smoothoperator
Thanks Smooth operator, That might be a good way to get rid of some play. I can see however, by the movement between the shaft and the arm, that the majority of the play is in the splines.
You might luck out on it and maybe another arm off of another grader might work. It may just be the arm that is worn, as the shaft should be out of some pretty good material.