This lawn tractor has been the best mower I have ever owned. It has a Kohler 15.5 hp engine and a six speed transmission. I was mowing in a straight line when the drive belt came off. Since the belts had never been changed I just chalked it up to the belts stretching. The old belts looked like new, but I replaced anyway. The belt seems to jump off the transaxle pulley with only a small amount driving. The furtherest about 20 yards. I have checked alignment and all pulleys and they seem ok. I have been having a problem with the brake not stopping well, so I adjusted the brake to factory specs and it now stops but throws drive belt quickly. This brake adjustment had to be adjusted about an inch and a halve which seems as though something has shifted at transaxle. Any ideas appreciated.
Make sure that the support bracket on the front or side hasn't came loose. If it comes off it will allow the tranny to rock, especially when the brakes are applied. the tilting will through the belt off of the tranny pulley.
I really expected to find the transaxle support loose, but all bolts and brackets are tight. Do you have any other ideas of what to look for ? Is it possible that the tension spring has lost enough pressure to allow the belt to jump off ? I am at a lose to identify the problem.
Other than the tranny support, the other possible reasons is bad spot in belt, bent or missing belt guide, worn idler pulley (especially the plastic ones), the spring could be loosing tension but is very rare.
The pulley that tightens the belt when you release the clutch pedal is the only pulley made of synthetic material. I removed this pulley and showed it to a lawnmower mechanic and he said it was good. I am wondering if this pulley could be worn down enough to cause my problem. It seems strange that I had mowed for about half an hour when the belt jumped off the first time ever. I know it is probably something simple, but hard to diagnose. Thanks for all your help. Maybe I should just order this pulley and see what happens.
