I have a 42in. Troy Bilt Super Broncho. I had just had some work done on it, including new blades. Within 2 minutes of it’s first use I ran over a rock. It started to make a metal on metal grinding sound. I figured I just have bent a blade, but each blade seems straight. I did notice what seems to be a fresh scratch in the inner surface of the deck near the grass chute. While I suspect that that is the cause I cannot figure out how running over a rock can make a blade LONGER. And if that is the cause, how do I make it stop?
I have a 42 inch Troy Bilt pony and had the same problem last week. There is a metal band on the inside of the deck that (at least on my mower) was loose and when I was on a slope it ground against the blades. *cut off metal band, no more grinding.
Plus, did the repair shop make sure that the deck was level and the nut in the front was tight? Maybe running over the rock knocked the deck out of kilter.
The blade may be straight, but is the shaft bent? Where’s the scrape? Is it where the top of the blade’s rubbing on the underside of the deck?
No, the scrape is on the inside of the deck wall, near the grass chute. It is not on the top. And when I hand turn the two blades one turns much more freely than the other, and it is the blade on the other side of the scrape that does not turn as well.
The blades could be out of synch and are hitting each other in the middle. A shear bolt could have been broken and the blade which is turning more freely shouldn’t be.
Two blades, I assume? Is there a timing (toothed) belt that drives the sprocket for each blade?
Reason I’m asking… I had the same problem on my 42 inch Cub Cadet last year; I ran over a rock, and then heard a lot of metal-on-metal noise. I removed the deck and discovered there was interference between the two blades when they rotated. When I hit the rock the timing belt must have slipped a few teeth on one of the sprockets, and the blades started hitting each other. I removed the belt, re-timed the blades (so that they were 90 degrees out-of-phase), reinstalled the belt, then reinstalled the deck under the mower. That fixed the problem.
The blades seem to be driven by a smooth belt, sort of serpentine. When I move the blades so they could touch, they do not.
Are they 90 degrees out of phase?