Jump to content

Nominations for Tractor of the Month
Garden Tractors and Parts on eBay



Photo
- - - - -

Speed control issue


  • Please log in to reply
12 replies to this topic

#1 blacktruck OFFLINE  

blacktruck

    New Member

  • Member
  • Member No: 4033
  • 21 Thanks
  • 46 posts
  • Location: Texarkana, TX

Posted September 01, 2015 - 07:22 AM

During operation of the 420, there are times when the ground speed increases with no input from the control lever. I would think an adjustment perhaps but where? Any others ran across this problem? It is a noticeable increase in speed. I have to pull the lever back to the neutral position to get back to mowing speed. Any ideas out there?



#2 boyscout862 ONLINE  

boyscout862
  • Senior Member
  • Member No: 8923
  • 9,744 Thanks
  • 7,517 posts
  • Location: N.E. Connecticut

Posted September 01, 2015 - 11:13 AM

I would check the governor first and then look for a vacuum leak. The vacuum leak may be related to the temperature of the engine. I saw a warpped manifold do this and a cracked one too. Good Luck, Rick


Edited by boyscout862, September 01, 2015 - 11:13 AM.


#3 blacktruck OFFLINE  

blacktruck

    New Member

  • Member
  • Member No: 4033
  • 21 Thanks
  • 46 posts
  • Location: Texarkana, TX

Posted September 01, 2015 - 12:29 PM

Good thought but I don't think it is that. The engine seems to be running a constant speed throughout this entire episode. I know the sound an engine makes when it is sucking air a bit, this one doesn't have that. Just from the feel and the sound of it, I believe it is related to the drive system. Thanks for the reply boyscout. Gotta be something and I'll keep hoping for more suggestions.

 

Ken



#4 olcowhand ONLINE  

olcowhand

    Red Tractor Nut & Diesel Addict

  • Staff Admin
  • Staff
  • -GTt Supporter-
  • Sponsor
  • Contributor
  • Member No: 20
  • 35,559 Thanks
  • 29,819 posts
  • Location: South Central Kentucky

Posted September 01, 2015 - 01:19 PM

Check that the attachment points of hydro to chassis are solid.  My 430 had lots of speed changes, especially faster when going downhill, but was smooth going uphill.  I first thought worn hydro, but turned out my frame was busted where it attached to the axles.  This allowed lots of flex which transferred to the hydro speed control linkages, which in turn caused big swings in speed.  Once I welded & reinforced this, all worked like new with no strange speed changes at all.  At first the cracks were hard to see, but once I zoned in on them, I was surprised how badly cracked up it was.


  • Texas Deere and Horse, blacktruck, TomLGT195 and 1 other said thanks

#5 WNYTractorTinkerer ONLINE  

WNYTractorTinkerer

    Tinker Master

  • Senior Member
  • -GTt Supporter-
  • Member No: 10789
  • 8,297 Thanks
  • 4,656 posts
  • Location: Avon, NY

Posted September 01, 2015 - 01:25 PM

Sounds like Hydro linkage slop vibrating which lets the hydro's georotor plate move a bit more than you intended..  Look for looseness at linkage joints..


  • TomLGT195 said thank you

#6 olcowhand ONLINE  

olcowhand

    Red Tractor Nut & Diesel Addict

  • Staff Admin
  • Staff
  • -GTt Supporter-
  • Sponsor
  • Contributor
  • Member No: 20
  • 35,559 Thanks
  • 29,819 posts
  • Location: South Central Kentucky

Posted September 01, 2015 - 04:22 PM

I did a thread on my 430 hydro speed changes.  You can read it HERE.



#7 blacktruck OFFLINE  

blacktruck

    New Member

  • Member
  • Member No: 4033
  • 21 Thanks
  • 46 posts
  • Location: Texarkana, TX

Posted September 08, 2015 - 08:47 AM

Sounds like Hydro linkage slop vibrating which lets the hydro's georotor plate move a bit more than you intended..  Look for looseness at linkage joints..

 

 

Check that the attachment points of hydro to chassis are solid.  My 430 had lots of speed changes, especially faster when going downhill, but was smooth going uphill.  I first thought worn hydro, but turned out my frame was busted where it attached to the axles.  This allowed lots of flex which transferred to the hydro speed control linkages, which in turn caused big swings in speed.  Once I welded & reinforced this, all worked like new with no strange speed changes at all.  At first the cracks were hard to see, but once I zoned in on them, I was surprised how badly cracked up it was.

Thanks guys for the ideas. Had not thought of those issues. I did have the body off recently and did not see any frame damage but I wasn't looking for that specifically. Linkage is on my radar screen now. Next time I'm doing some quality time in the garage, I'll dig into that. This one is just like you describe, downhill it gets to moving along at a fairly good speed with no input. Level ground or uphill all seems well. Thanks again for the ideas. I'll check them out.  

Have a great day all.


  • olcowhand and WNYTractorTinkerer have said thanks

#8 olcowhand ONLINE  

olcowhand

    Red Tractor Nut & Diesel Addict

  • Staff Admin
  • Staff
  • -GTt Supporter-
  • Sponsor
  • Contributor
  • Member No: 20
  • 35,559 Thanks
  • 29,819 posts
  • Location: South Central Kentucky

Posted September 08, 2015 - 08:57 AM

I'm pretty confident you'll find a cracked frame at the axle mount area.


  • WNYTractorTinkerer said thank you

#9 blacktruck OFFLINE  

blacktruck

    New Member

  • Member
  • Member No: 4033
  • 21 Thanks
  • 46 posts
  • Location: Texarkana, TX

Posted September 08, 2015 - 09:57 AM

I'm pretty confident you'll find a cracked frame at the axle mount area.

I sure hope you're wrong but I will find out.

Thanks



#10 olcowhand ONLINE  

olcowhand

    Red Tractor Nut & Diesel Addict

  • Staff Admin
  • Staff
  • -GTt Supporter-
  • Sponsor
  • Contributor
  • Member No: 20
  • 35,559 Thanks
  • 29,819 posts
  • Location: South Central Kentucky

Posted September 08, 2015 - 01:55 PM

I sure hope you're wrong but I will find out.
Thanks

It's not hard to repair. Only took me an afternoon.

#11 blacktruck OFFLINE  

blacktruck

    New Member

  • Member
  • Member No: 4033
  • 21 Thanks
  • 46 posts
  • Location: Texarkana, TX

Posted September 10, 2015 - 01:05 PM

I sure hope you're wrong but I will find out.

Thanks

What is your opinion of what caused it? Design, implements or misuse, what was your remedy?



#12 olcowhand ONLINE  

olcowhand

    Red Tractor Nut & Diesel Addict

  • Staff Admin
  • Staff
  • -GTt Supporter-
  • Sponsor
  • Contributor
  • Member No: 20
  • 35,559 Thanks
  • 29,819 posts
  • Location: South Central Kentucky

Posted September 10, 2015 - 01:08 PM

What is your opinion of what caused it? Design, implements or misuse, what was your remedy?

 

Check the 2nd post I made in your thread.  It has a link to my repair thread on the subject.


  • blacktruck said thank you

#13 blacktruck OFFLINE  

blacktruck

    New Member

  • Member
  • Member No: 4033
  • 21 Thanks
  • 46 posts
  • Location: Texarkana, TX

Posted September 10, 2015 - 04:19 PM

Check the 2nd post I made in your thread.  It has a link to my repair thread on the subject.

Thank you sir. Next time home I will pull the pan and check that. Looks like a bit of an underengineered part before your repair.


  • olcowhand said thank you




Top