TC33D hand throttle 'slipping'

   / TC33D hand throttle 'slipping' #1  

buckthorn

Member
Joined
Jul 11, 2005
Messages
36
Location
Black Earth, WI
Tractor
New Holland TC33D, John Deere x590, John Deere 325, Kubota RTV 900
I've been noticing over the past month or two that the hand throttle on my TC33D keeps 'slipping' downwards (to about 2000-2200 RPM) while I'm trying to mow. For a while it seemed to hold once the tractor warmed up. But now I have to hold it up with my hand in order to keep the RPMs at about 2500-2600 and the PTO speed at 540. This never happened for the first 4-5 years -- it just started this summer. I thought at first that maybe something with the mowing attachment was causing some resistance, but the same thing happens regardless of whether the PTO is engaged. Does this sound like something with the throttle handle that needs to be tightened, and if so, what and where? And is it accessible? I'd hate to have to drag it to the dealer for something like this.
 
   / TC33D hand throttle 'slipping' #2  
This is a known problem and has been reported several times on this forum. Take the panels off underneath the dash and either double nut the throttle or use Loctite after tightening the throttle. Once you get the panels off, it will be clear what needs tightening.
 
   / TC33D hand throttle 'slipping'
  • Thread Starter
#3  
Thanks Mike, I'll give it a shot. This thing's been driving me a little crazy with all the late-season mowing we need to do. I had done a quick forum search, but apparently not far enough back to dig up the relevant posts.
 
   / TC33D hand throttle 'slipping' #4  
Mike, question.. Did the new ( anything newer than the 4-digit NH's ) units do away with the friction disk setup like the older models like my 7610s.. etc?.. I've never had one of the new tc's apart for a looksee..

soundguy
 
   / TC33D hand throttle 'slipping' #5  
It is easier to get to the friction disk by just removing the 2 screws in the instrument panel. I have done it by removing the side panel but the instrument panel method is faster and easier. Lift out the instrument panel and you will see the friction disc on the right side below the throttle. Move the throttle lever and you will see the area to tighten the nut slightly.
 
   / TC33D hand throttle 'slipping' #6  
Mike, question.. Did the new ( anything newer than the 4-digit NH's ) units do away with the friction disk setup like the older models like my 7610s.. etc?.. I've never had one of the new tc's apart for a looksee..

soundguy

Hi Chris, my TC25D has the friction disk.
 
   / TC33D hand throttle 'slipping' #7  
I guess that's one benefit to having a larger tractor.. i was able to just snake my hand up under the cowl and look thru diagonally from the other side of the tractor and use a stubby wrench when i tightened my tension nut / friction disc onmy 7610s a few years back.

Glad to hear they did not totally change / redesign the system... you gotta watch engineers .. they love to change things! ;)

soundguy
 
   / TC33D hand throttle 'slipping'
  • Thread Starter
#8  
I worked on this today and it was a reasonably easy job (it took me about a half hour, but I work pretty deliberately, especially when it's on an area I haven't worked on before). I used threadlock on the nut. It's a little tight getting the wrench and socket in there, but not overly so. The only other thing I would say is that the difference between tightening it too much and "just enough" is very slight, so you want to keep checking the throttle handle action until it moves with just a little effort, but no looser than that.

Thanks for the help! This board and the generous people on it gave saved me yet again!

This is a known problem and has been reported several times on this forum. Take the panels off underneath the dash and either double nut the throttle or use Loctite after tightening the throttle. Once you get the panels off, it will be clear what needs tightening.
 
   / TC33D hand throttle 'slipping' #9  
Mike, question.. Did the new ( anything newer than the 4-digit NH's ) units do away with the friction disk setup like the older models like my 7610s.. etc?.. I've never had one of the new tc's apart for a looksee..

soundguy

Chris, I had to do it on my TC29D which is about a 2001 model. It took all of 20 minutes to take the cowling off and tighten it. I haven't had problems since. That happened about 3 years ago.
 
   / TC33D hand throttle 'slipping' #10  
Glad to see they are still using that type of disc system... thanks for looking.

sounduy
 
 
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