No idea whats going on with this thing and its driving me up the wall LOL. I have bought a new belt, tightened the idler arm tension spring, and this belt keeps jumping off as soon as I engage the blades. I just got it back a couple of weeks ago from the shop and it cut perfectly for me all day. The next day it started this whole belt jumping mess and I haven't been able to figure it out. Spindles look fine with no dents in them. They don't look out of alignment either. As soon as I hit the switch the deck shudders slightly and the belt jumps right off. Anyone have this problem? Could a bent deck cause this? Thanks in advance.
Have a long think about it from the belt's point of view.
When the clutch fires the engine suddenly jerks the belt which "pulls" the belt back towards the engine causing the deck pulleys to rotate.
If anything prevents this FREE rotation, then the belt will pull the deck backwards towards the engine pulley causing the deck to shudder
This creates a lot of slack in the already slack side of the belt which will then fall off one of the pulleys.
Most common culprits
Build up under the deck
build up around the pulley
Faulty spindle brake ( don't think you have one )
overtight spindle bearings ( tappered roller types only )
Tight spindle bearing
Over tight tensioning pulley
I have yet to lay a spannar on a tank so can not give specific information.
Wellll.. given the history you post I would be looking at belt tension.
However any debri no matter how insignificant could also be a likely
factor. So yeah, housekeeping first
Having same problem, we have cleaned deck replaced belts, etc. any other suggestions? Considered replacing spindle assembly but they are showing to run $150-200 each just for spindle.
I'm having the same issues my PTO idler arm isn't tight and my belt keeps jumping off. I don't think it's the spring, but could be. The pulley is to close to the belt, once I engage the pto, the belt rubs against itself.
I showed a video of my issue to my mechanic, he told me over the years of wear and tear, the deck shifts backwards and loosens the tension of the belt. A quick solution is to use a tighter belt, maybe 1 to 2 inches. The long-term solution is to weld the deck where the bolts created an oval hole instead of a circular hole. He stated that the new tanks allow the owner to adjust the mower deck to tighten the belt.
check out z-force service manual 2003-2006 idler arm hardware for being loose page 3, i would check all hardware on deck for being loose especially idler pulleys, etc.
