Qa42 gearbox issue

[DewDrop Junior Member Find all posts View Profile Close DewDrop]

Last snowfall my snow thrower died. I noticed the input shaft into the gearbox spins and the output shaft does not. I opened the cover to find that the snap ring on the input shaft fell off and the key fell out causing the gear to not move. Further inspection found the whole shaft actually moved back ( towards the tractor ) about 3/4 inch. I reinstalled the shaft, key and snap ring, but I am curious on why it happened. Vibration? Pulley not adjusted? The snap ring looks good, it held tight when I reinstalled. The pulley LOOKS lined up with the pto. Maybe there’s a better method of lining up pulley, or maybe I’m just missing something. Any suggestions would be greatly appreciated.

[J-Mech Owner Find all posts View Profile Close J-Mech]

Well, there is supposed to be a snap ring on the gear side, and behind the seal on the pulley side as well. Sounds like since the shaft was able to be pushed the other way, the snap ring on the opposite end is also either off, or missing. Why you lost the snap ring is beyond me. How you didn't eat it up in the gears before the key fell out is also a shock. As far as the pulley goes, you basically align it by sight, and by sliding the pulley on the shaft, so unless you can't see straight, it should be fine.

Don't know if that helps any.... but that's all I can think of.

[DewDrop Junior Member Find all posts View Profile Close DewDrop]

The snap ring is still in place and undamaged on the back side towards the pulley. I think I lucked out because I wasn’t throwing any snow when it happened, and it must not have taken long for the key to fall out once the shaft backed out. I was hoping there was some common cause and solution, hopefully it was a one time thing.

Thanks for the response. I will update after the storm this weekend.

[DewDrop Junior Member Find all posts View Profile Close DewDrop]

I cleared my driveway today with no issues. Then I moved the cars and realized I never tightened the belt. As soon as I made my second pass, the snap ring and key fell out again. So I must just be over tightening the belt. I reassembled everything and kept the belt tension backed off.

[J-Mech Owner Find all posts View Profile Close J-Mech]

I cleared my driveway today with no issues. Then I moved the cars and realized I never tightened the belt. As soon as I made my second pass, the snap ring and key fell out again. So I must just be over tightening the belt. I reassembled everything and kept the belt tension backed off.

No, you have an issue somewhere. A tight belt won't pop that snap ring off unless the bearings are going bad, or the shaft is worn. You need to take the box apart and see what is going on. If you need them, I can get the bearing numbers and seal numbers and post them up. They aren't expensive at all. Member JeffinPA makes new shafts if the shaft is bad. Only thing in that box that is hard to get are the gears. Fix it before you take one of them out. Usually if you pop a gear, you are looking for another gear box. I have yet to find another supplier, or gear that is the same. Good used, or NOS is the only choice on them.