PTO will not engage after striking rock

   / PTO will not engage after striking rock #1  

joehogan

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Nov 5, 2005
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3
While mowing the other day, my Model 3240 Cub Cadet with 54" mowing deck came to an abrupt halt when I hit a large flat rock that appeared without warning. The tractor still ran but the mower would not engage. The front PTO belt had snapped. I replaced both PTO belts and thought I was home free but moving the PTO switch handle to the "mow" position does not activate the mower blades. The blades and the belts on the blades are all fine, as is the front drive shaft on the mower deck.

Could someone please suggest a solution to my problem. Did my abrupt stop after tangling with that rock damage the PTO switch? What steps do I need to take to isolate and fix this problem? Thank you sincerely in advance for your help.
 
   / PTO will not engage after striking rock #2  
I have a 3235 with 54" morer & have had the bolt in the knuckled shaft in front of gear box on morer shear that mite be your deal. Good luck Mick
 
   / PTO will not engage after striking rock #3  
You might need two people for this one to sit on the machine the other to oberserve the PTO and the linkages...maybe the bolts on the deck attachment snapped and its free spinning? or maybe the deck gearbox is hosed and free spining...Make sure the PTO vacuum and enagment assembly are actually working...

Good luck narrowing it down

Duc
 
   / PTO will not engage after striking rock #4  
To add to Duc's comments. The electrical selenoid that actuates the vac diaphram is not the most reliable in the world. They have a tendency to get stuck and fail to open thus the pto doesn't get engaged.

I partially disassembled mine a long time ago and cleaned it up a bit and it has worked ever since. That was the second sel on my 02 tractor.

By the way Duc, how is your selenoid working? Have you had any problems since I told you how to work on this part? I know that was over a yr ago.
 
   / PTO will not engage after striking rock #5  
</font><font color="blue" class="small">( To add to Duc's comments. The electrical selenoid that actuates the vac diaphram is not the most reliable in the world. They have a tendency to get stuck and fail to open thus the pto doesn't get engaged.

I partially disassembled mine a long time ago and cleaned it up a bit and it has worked ever since. That was the second sel on my 02 tractor.

By the way Duc, how is your selenoid working? Have you had any problems since I told you how to work on this part? I know that was over a yr ago. )</font>

I wrapped it with foam (same as the prefoam on the air cleaner). So far so good....This fall season will tell me how well it works - it gets real dusty and dirty with mulching leaves
 
   / PTO will not engage after striking rock
  • Thread Starter
#6  
Hi Mickey. Thanks to you and the others who have come to my rescue. When the PTO handle is activated, the vacuum actuator slowly operates, but not far enough to actually make the belts turn the PTO.

If I need to clean either the vacuum actuator or the solenoid's insides, how do I do that?

Once again, thank you all so much. Truly appreciate it.
 
   / PTO will not engage after striking rock #7  
Joe, see my reply to your PM.

Does look like Duc did so something and has found a way to keep the Sel. working.
 
   / PTO will not engage after striking rock #8  
</font><font color="blue" class="small">( Hi Mickey. Thanks to you and the others who have come to my rescue. When the PTO handle is activated, the vacuum actuator slowly operates, but not far enough to actually make the belts turn the PTO.

If I need to clean either the vacuum actuator or the solenoid's insides, how do I do that?

Once again, thank you all so much. Truly appreciate it. )</font>

Joehogan,

Its easier to respond here because it might need a few perspectives. My main concern is the damage a rock would cause on your deck & gear box up through your vacuum activated PTO. If you can test the deck to make sure the spindles, gear box, blade are not bent or preventing the PTO from turning at least that would eliminate a few things...

Next is to watch the vaccum activated brake system operate without the side panels. You can test the line to the vacuum tank by pulling the hose off and tesing it with your finger over it. You will feel suction if it works or not and by turning on or off the PTO switch on the dash....The activator solenoid is mounted on the firewall and is the last length of hose that goes to the vacuum tank. The solenoid is a little piece of junk - the bottom has a plate that can be removed. There will be a very small cotton filter there. You can see how dirt can quickly get in there. You can let the spring come out - it will fall out by itself. Just blow some compressed air to clean it out. Reassemble and hopefully you will get good suction.
If your machine is still under warranty, they will swich it out for you at the dealer. Otherwise they are cheap enough....
All I did was wrap some prefoam around the bottom and tied it off. I cant say yet if that will help, because my dirtiest time frame will be now with mulching leaves.

Let us know what happens

Duc
 
   / PTO will not engage after striking rock #9  
This should help identify the solenoid - I doubt the vacuum tank went bad on you - just a guess
#16 725-3278
Solenoid, Vacuum Actuator
 

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   / PTO will not engage after striking rock
  • Thread Starter
#10  
I thank you all sincerely for the suggestions and assistance in fixing my PTO problem. I learned alot about my cub cadet during this process. /forums/images/graemlins/smile.gif

I installed two new PTO belts after removing the hood, grille, side panels, muffler assembly, and the muffler heat shield. I then loosened the two shoulder screws below the belts enough to let me easily install the new belts.

I then started the tractor to see if the PTO would activate, it would not. At that point I disengaged the mower deck from the PTO and turned the drive shaft manually to insure that the problem was not in the deck itself. The drive shaft turned and all of the blades rotated properly.

Next, I removed the vacuum actuator solenoid, separated it from the hoses and wiring harness, removed the small cover on the bottom of the assembly, the spring and the small cloth filter. I washed the filter in degreaser and let it dry [it was very dirty] and blew out the rest of the unit with compressed air. This proved to be the solution to the problem.

I then reassembled everything and /forums/images/graemlins/laugh.gif now I am up and running.

Men I couldn't have done this without your guidance and knowledge. Thank you sincerely!
 
 
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