Was curious if any has experience changing the oil seal on the gearbox output shaft on a walk behind concrete trowel? Said trowel is a MQ Whiteman 36" four blade. The gearbox takes the horizontal shaft from the motor and via a worm gear arrangement, turns the vertical output shaft. Machine is pretty clean from abusive concrete and looking at the seal and the manual, looks like the typical grease seal. Bearing shows no play. Wonder why it went out but have to change it 'cause the one drip a month has changed to a little puddle in a couple weeks. Am thinking to remove the gasoline and the oil from the Honda engine and then invert the machine to allow access from the above. Was thinking to use the storage stand and perhaps it will hold the trowel upside down (once I remove the handle). But better to keep dirt and debris from the seal removal from falling inside, maybe just turn the trowel on edge and conjure something (unistrut, plywood triangle, clamp to bench, etc etc) to facilitate that position....either way, working from underneath isnt going to be fun. Is the typical seal removal pry tool OK? Or get the one with the pivot bar that is made for seals on shafts? Or a slide hammer and some form of seal removal screw attachment to a slide hammer? Here is stand with the two trowels:
Here is an update to the walk behind trowel. Got the fuel drained out and stood the trowel on a small work table and lashed it to the wall shelving. The blade hub has one lock screw and (fortunately) the shaft has a recess - none of that dreaded upset condition on the shaft. A little pull with only hand torque on a puller and the blade hub was removed. The woodruff key had to be removed in order for the seal to slide by and that took a bit of cajoling. Once the blade hub was removed and re-inspection: yep there was some end play and bearings required inspection. The lower cover was removed and the tapered bearings had seen better days. Wasn't a solution to simply R&R the seal. Expecting to replace bearings and reassemble. One pic shows the trowel leaned against the wall .... with the cover off and then the grease diversion into the pail Other pic shows inside the gearbox with the worm remaining. Center of pic is the tapered roller bearing which supports the weight of the trowel and is observed with some pitting failure.
Glad to hear it came apart easily, the only thing I have worked on on one of them was the carb from sitting too long got all gummed up.
I have the same trowel, but I think mine's a few years older. Mines apart right now because my other gearbox seal was leaking... the horizontal one that the motor spins. Its got a housing that holds the seal and unbolts from the side of the gearbox. Makes changing the seal easy. Unfortunately there is a big O ring on the housing that I couldn't reuse, so Im waiting until Monday to hit the industrial supply store.