Honda 4518 vibration / noise when mowing - need help diagnosing

[joeb]

Experiencing an intermittent vibration/noise that sounds like it's related to drive belt pulleys, but pretty sure that's not the case. Problem comes and goes while mowing (PTO engaged). Pretty sure mower deck is not the culprit given all pulley bearings seem fine. Belts are good. Blades not out of balance Thinking it may be related to the PTO...not sure? Lately the vibration/noise is more frequent. It's significant, I can feel the vibration through my feet, so again thinking it must be coming from engine/PTO not the mower deck. Help! This tractor has been great for 13 years (recently put on new tires, fixed oil leak with new gaskets for oil pump assembly) ...I'm invested now and didn't want to give up...wanting to get several more years service if possible.

 

[robert@honda]

Experiencing an intermittent vibration/noise that sounds like it's related to drive belt pulleys, but pretty sure that's not the case. Problem comes and goes while mowing (PTO engaged).

Joe, what's the frame serial number off the tractor? [serial number is on a plate on the frame near the right front tire in the form of "XXXX-1234567"] I can look service information for this tractor. There were a few service bulletins issued for certain units; here's brief list....nothing specifically for your symptoms, but might be related??:

Lawn Tractor #11, PTO Clutch Wear, units prior to frame serial number -3000762
#13, Tensioner Pulley, Failed Mower Deck Belt: all units
#14, Failed Mower Deck Belt, depends on serial number on mower deck, and this is only for the original, factory-installed belt.
#15, Transmission Surging 1000001-1099999 and 2000001-2002230
#17, PTO slip, drag, premature wear, 3000001-3000593
#21, Failed mower deck belt, failed tensioner pulley, (hydrostatic trans. mdoels only)

 

[joeb]

Robert - thanks. Serial #: MZAT-4001240. Thought I'd found the problem (rough spindle bearing) but after replacing, mowed again and the vibration/noise is still there - reinforcing my thought that this is not related to the mower deck. How do you determine if there's an issue with PTO clutch/PTO bearings? I took another look at the two drive belt pulleys (directly below the PTO assembly) and found them to be extremely hot after use, like burn your skin hot...is that normal? Those pulleys spin freely/smooth...so bearings appear good. Of these two, noticed the tensioner arm has some play/slop where it pivots on the frame bracket...is that by design? I'm stumped!

 

[robert@honda]

Robert - thanks. Serial #: MZAT-4001240. Thought I'd found the problem (rough spindle bearing) but after replacing, mowed again and the vibration/noise is still there - reinforcing my thought that this is not related to the mower deck. How do you determine if there's an issue with PTO clutch/PTO bearings? I took another look at the two drive belt pulleys (directly below the PTO assembly) and found them to be extremely hot after use, like burn your skin hot...is that normal? Those pulleys spin freely/smooth...so bearings appear good. Of these two, noticed the tensioner arm has some play/slop where it pivots on the frame bracket...is that by design? I'm stumped!

I'm going to bump this up to some of our more experienced tractor guys here in the building. You are in luck, as the model engineer for riding equipment is set to retire in less than two weeks. :biggrin: I'll let you know ASAP what I find out.