Combustioneer Gearbox noises/stuck

[fizban]

Hey everybody,
My combustioneer 77 has been running pretty well for a bit. But last night I came by and found it off. I realized my surge suppressor had tripped and when I restarted it the gearbox was stuck.

The oil level and color looked good. I did previously notice that the previous owner kept it quite full, I have not kept it as full. I assume there could be issues from overfilling potentially.

I pulled the top off and didn't see any obvious issues. The handwheel/output shaft would rotate back and forth by hand. I ended up putting a wrench on the end of the input shaft and turned it back and forth a bit until it "broke" free a bit. Didn't seem to damage anything and it turned okay after that.

Running again I did noticed a light rythmic knocking sound, seems to be at the input shaft speed. I was thinking maybe the bearings on it are bad. Not sure if that would cause it to lock up temporarily? I guess maybe if they overheated.

I assume I need to pull the bearing/bushing cover and check them out? Thanks for any input. I'm somewhat mechanically minded, but never really messed with a gearbox. I've included a diagram for anyone that isn't familiar with it.

Ross

[carlherrnstein]

It's possible that the ball cages in one of the bearings has disintegrated an bound the bearing up. If I remember correctly my gearbox has bearings marked Hoover.

I would double check the setscrews on the belt pulley I can't count how many times I've seen pulleys walk around on their shaft because the screw isn't tight. I would also look the belt over carefully it might be starting to fail.

I recommend getting both input bearings a the two lip seals an o ring and mess with it in the spring. It's kinda cold to shut down right now.

[Hambden Bob]

Hern,I've never gotten "My Hooks" into one of these little gems but I've gotta' go with Your Theory..!! Would that shaft show up/down or side to side slop play to confirm it..?? With the rotten "Polish Vortex" Low Temps that are befalling Us in N.E. Ohio and well beyond,Yes it's a rotten time to shut down for "Major Surgery"..!! To me, the "Hat Trick" would be to have Howard Hughes' Money and pick up a working spare,install it with a minimum of downtime and bench rebuild that "Ailing Lizard" that's giving him "The Fits" Yes,I realize that I speak "Bob-Bonics" which usually needs it's own Interpreter,but generally I get the point across while generating a few self-deprecating laughs

[fizban]

You may actually be right about the pulley. I went back and looked and I think it is lightly hitting the housing and that is what is making the slight noise. It looks like it's a little out of alignment maybe. I'll try to loosen the set screw and see.

I appreciate the detailed answer. I actually do have a another one, it's a little buried in a trailer but I can get it out if I need to take this one down.

[carlherrnstein]

Hern,I've never gotten "My Hooks" into one of these little gems but I've gotta' go with Your Theory..!! Would that shaft show up/down or side to side slop play to confirm it..??

Possiblity, depending on which bearing it is, if it's the one opposite the pulley probably not. Normally ball bearings run until they lock up/fall apart or get replaced because they are unbearably loud. I had a Hyundai that the front wheel bearings were going out on and at low speed there was a crunchy noise, but at high speed it sounded like a roar. Oddly enough their was no play in the wheel. When I replaced the bearings they fell apart and the balls weren't balls anymore, they had grooves mashed in them.

[fizban]

It ended up the set screw was about loose. I was able to get the pulley moved to waste slightly and re-tightened, and it seemed to get rid of the noise. I believe that maybe was my only issue. I did notice the top/blower looks like it has a little wobble to it. But that’s probably a summer project.

I appreciate the help. Looks like we will need the heat this week.