PTO clutch vibration

[Dragonflyfarm]

I have a 2005 Exmark Lazer (about 700 hrs) and am having a vibration problem with PTO clutch. While disengaged, there is vibration and wobbling of the clutch on the engine shaft. Thinking it was a failed clutch, installed a new one with same result. Worrying about failed lower engine shaft bearings, I removed clutch again and the hydraulic drive pulley. There was zero play in the shaft and no sign of oil leakage from the seal. Ran engine with just hydraulic drive belt on and everything ran smoothly. Checked all pulleys and all rotate freely with no play. Reinstalled new clutch with same result. Stumped! Maybe new clutch is defective?

 

[hlw49]

Ever think the crank shaft might be bent? The farther away from the bottom of the engine the worse it would be and this where the clutch in mounted. Should be able rig some thing to check it. Just take the clutch off and check it.

 

[Bertrrr]

check your belt

 

[Dragonflyfarm]

Ever think the crank shaft might be bent? The farther away from the bottom of the engine the worse it would be and this where the clutch in mounted. Should be able rig some thing to check it. Just take the clutch off and check it.

Thank you for the suggestion. I have removed both the clutch and the hydraulic drive pulley and watched the shaft. No play at all in the shaft when I try to move it from side to side (although there may be more force required than I can do by hand). No wobble at all visible when I run the engine. No sign of oil leakage from around the seal. I have videos of all these inspections and the wobbling clutch and I will try to post them here in the next hour.

 

[Dragonflyfarm]

check your belt

That also has been suggested by the dealer, as well as checking the tension on the tensioner pulley. The dealer also suggested trying a new belt, although at $100 a pop, I have been hesitant to do that. The deck belt has been on for 200 hrs or so. The wobble happens when the PTO is disengaged, so I wonder how the belt would affect the wobble, unless it is too tight or too loose.

 

[Wrenchit]

I have a 2005 Exmark Lazer (about 700 hrs) and am having a vibration problem with PTO clutch. While disengaged, there is vibration and wobbling of the clutch on the engine shaft. Thinking it was a failed clutch, installed a new one with same result. Worrying about failed lower engine shaft bearings, I removed clutch again and the hydraulic drive pulley. There was zero play in the shaft and no sign of oil leakage from the seal. Ran engine with just hydraulic drive belt on and everything ran smoothly. Checked all pulleys and all rotate freely with no play. Reinstalled new clutch with same result. Stumped! Maybe new clutch is defective?

Did you use a dial indicator to see if there is any runout on the bottom of the crankshaft?
It would be more accurate.Or use a coathanger afixed to the fame and rotate the engine by hand while someone watches to see of you have the slightest of run out.
Also, its a shot in the dark, But I have seen that exact issue caused by loose engine bolts or a cracked mounting plate where the engine bolts attatch to the frame (On One. the cracks were under the block so you souldnt see them unless you lifted the engine block. That one was on a garden tractor with an overised engine that was retrofitted on it. Exact same symptoms as you desribe. You should be able to see from underneath, but not always.That one took me awhile to figure out as it looked fine from underneath. It wasnt a horrific vibration, just really annoying.

 

[Dragonflyfarm]

Did you use a dial indicator to see if there is any runout on the bottom of the crankshaft?
It would be more accurate.Or use a coathanger afixed to the fame and rotate the engine by hand while someone watches to see of you have the slightest of run out.
Also, its a shot in the dark, But I have seen that exact issue caused by loose engine bolts or a cracked mounting plate where the engine bolts attatch to the frame (On One. the cracks were under the block so you souldnt see them unless you lifted the engine block. That one was on a garden tractor with an overised engine that was retrofitted on it. Exact same symptoms as you desribe. You should be able to see from underneath, but not always.That one took me awhile to figure out as it looked fine from underneath. It wasnt a horrific vibration, just really annoying.

I do not have a dial indicator, but I will try the coat hanger trick. I wish I could attach the videos here, but I think they will be too large. I think they are very informative. I could post them on dropbox and give you access to them if you have the time. I have run the engine with the clutch and hydraulic drive pulley removed, and I cannot see any wobble in the shaft. The wobble of the clutch when it is on the shaft is pretty dramatic -- causes the deck belt to slap back and forth even though the PTO is disengaged. I realize that there may be a slight run out not visible to the naked eye. Would one expect runout with only 685 hours on the engine? On the other hand, it is 19 years old. I also will check as much as I can for loose engine bolts and/or cracks in the mounting plate.

 

[Dragonflyfarm]

I do not have a dial indicator, but I will try the coat hanger trick. I wish I could attach the videos here, but I think they will be too large. I think they are very informative. I could post them on dropbox and give you access to them if you have the time. I have run the engine with the clutch and hydraulic drive pulley removed, and I cannot see any wobble in the shaft. The wobble of the clutch when it is on the shaft is pretty dramatic -- causes the deck belt to slap back and forth even though the PTO is disengaged. I realize that there may be a slight run out not visible to the naked eye. Would one expect runout with only 685 hours on the engine? On the other hand, it is 19 years old. I also will check as much as I can for loose engine bolts and/or cracks in the mounting plate.

I uploaded the video to YouTube. It was taken with an iPhone in slow-motion mode so that you can see what happens. This is the new clutch I installed. The old clutch did the same thing. The PTO is disengaged. The bolt at the bottom of the shaft does not seem to wobble, although it might so slight as to not be easily visible.