Tractor lurching in downhill situations: Tractor Projects  -- General Tractor Discussion Forum and Review Tractor lurching in downhill situations: Tractor Projects -- General Tractor Discussion Forum

  parts   |   manuals   |   discussion   |   photos   |   podcast   |   reviews   |   specs   |   dealers   |   classifieds   |   contact   |   faq   |   myProfile   |   home          Login Now | Sign Up


FAQ:   What is a tractor?

Forum Index
New As Posted | Active Subjects



www.emerichsales.com - New & Used Equipment
          View Tractors For Sale!


www.partsbynet.com - Lawn and Garden Equipment Parts


Bernardsville Landscape Lighting
Click to Post a New Message!

Discussion Boards > Active Subjects > Messages as Posted > Tractor Projects Forum

Page [ 1 ] |
Reply | Pop Up Window Reply | Add PhotoAdd Photo
 09-04-2001, 23:38 Post: 31583
dwilson



Join Date: Jul 2003
Location: Galesburg, IL & Ferryville, WI
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 22
 Tractor lurching in downhill situations

I have a JD 4400 HST with 200 hours. Today for the first time, when going downhill in road gear, the tractor would not maintain a steady rate but seemed to lurch a bit, as though it were freewheeling and then being held back by the engine. Always before it went down the same hills at a steady pace, the engine holding the tractor back from gaining too much speed. Any ideas about what is the problem?






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us | Stumble This

 09-05-2001, 06:45 Post: 31585
TomG

TP Contributor

Join Date: Feb 2002
Location: Upper Ottawa Valley
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 5406

2
Filter by User
 Tractor lurching in downhill situations

Diesels, unlike gas engines, don't have much engine braking. The governor does vary the throttle in response to changing loads to maintain constant RPM. If the RPM's are staying constant, it sounds like the governor is going back and forth between adding and reducing throttle to maintain RPM. A faulty governor can become erratic, but the governor may be OK and differences in load, road, hills, wind etc. might be the cause. Governors on some tractors are more adjustable than others. The only common adjustment is the max no-load RPM adjustment, which you might check. If you were pushing it in road-gear, you might be operating around the max no load point. It's speculative, but a high setting might slack the governor springs beyond their limits of reliable operation. I'm not sure how the governor would behave if a heavy load tended to push a tractor down a hill at an RPM greater than the max no-load point.






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us | Stumble This

 09-05-2001, 07:37 Post: 31589
TomG

TP Contributor

Join Date: Feb 2002
Location: Upper Ottawa Valley
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 5406

2
Filter by User
 Tractor lurching in downhill situations

Dang. Think I said it backwards. I believe that raising the max no-load point would tighten rather than slack the springs. Throttle is reduced when the governor weights spin outward. Increasing the spring tension means that it takes a higher rpm to spin the weights out the same distance. Same idea though. I don't know how a governor would behave if a load was pushing a tractor downhill near the max no-load point.






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us | Stumble This

 09-05-2001, 13:02 Post: 31600
Doug Huebner



Join Date:
Location:
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 1
 Tractor lurching in downhill situations

The other Doug in Wis:
I have a 4300 and am experiencing the same problem. It does not matter what range [a,b,c] that it is in. We live in the hilly SW section of the state and have lots of ups and downs on the property. It can get a bit exciting when you try to go down hill at a constant speed and the tractor starts to feel like it is free rolling. You pull your foot off of the hydro and the brakes lock, potentially sending you skiding. Or you just get a jurky motion like the brakes are engaging and releasing. I just ran out of warrenty, but will try to get the dealer to do something about it.






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us | Stumble This

 09-05-2001, 15:10 Post: 31603
Murf

TP Contributor

View my Photos

View my Photos  Pics
Join Date: Dec 1999
Location: Toronto Area, Ontario, Canada
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 7018
 Tractor lurching in downhill situations

I used to have a similar problem with a Hydro-drive loader, when going downhill under load, the dealer finally (after consulting with the manufacturer) discovered that what was happening was that the weight of the unit going downhill was causing the machine to drive the motor, instead of the motor driving the machine, if that makes any sense. The lurching was the hydraulic relief valve and the motor's governor playing tag with each other, it was solved by replacing a defective check valve in the fluid lines to the drive unit. This particular unit had a pilot-circuit operated one-way valve (the same one that causes 'braking' when the pedal is released) which controlled fluid flow through the drive motor. Have your dealer check into it. Best of luck.






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us | Stumble This

 09-06-2001, 22:45 Post: 31642
Mike S.



Join Date:
Location:
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 1
 Tractor lurching in downhill situations

My first 4400 began lurching and periodically freewheeling at 50 or 60 hours--I never knew when it would zoom down the pond dam or head for the corner of the deck instead of slowing and stopping as it should have. This was an early model 4400 that had metallic contamination which caused issues with several components, including the hydro transmission which was replaced under warranty and that cured the lurching and freewheeling. I would be curious how many metal filings you found on the suction screen when you replaced the transmission fluid--I found almost a half cup of metal filings. My present 4400HST just turned 60 hours and today I drained the transmission fluid and cleaned the suction screen and did not find more than four tiny metal filings--a BIG improvement over the first 4400HST that was subject to JD's lack of quality control. Mike S.






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us | Stumble This

Reply | Pop Up Window Reply | Add PhotoAdd Photo


Page [ 1 ] |

Discussion Boards > Active Subjects > Messages as Posted > Tractor Projects Forum

Thread 31583 Filter by Poster:
Doug Huebner 1 | dwilson 1 | Mike S. 1 | Murf 1 | TomG 2 |




Most Viewed

+ Hydraulic Top Link
+ Digging farm pond
+ Info on Honda 6522 Compact Tractor
+ Magnatrac Crawler Review
+ Farm Bridge over seasonal creek
+ Home made cab
+ Calculating hydraulic tonnage rating
+ Cub Cadet Lo-Boy 185
+ Temporary patch to hydraulic line?
+ Price Check Kubota L235

Most Discussion

+ Hydraulic Top Link
+ Rear Log Spliter Build Project
+ Small Stump Suggestions?
+ Liters to cubic inches.
+ Anyone ever use a ROPS?
+ Flipping-Tractors
+ TRACKS COME OFF
+ Attempting to install a well
+ Hydraulic sawmill carriage
+ Food plot secrets

Newest Topics

+ PTO shaft mounted pump
+ 240 Massey
+ pto sprayer pump s volume
+ Hydraulics Take the quiz
+ New Holland 8260 Shuttle Problems
+ rear remote hydraulic control system
+ Restoring 1910 for my property
+ Rear Log Splitter Build Project Part 2
+ Rear Log Spliter Build Project Part 1
+ Things you can use your Tractor for













Turbochargers for Tractors and Industrial Machines
Cab Glass for Tractors and Industrial Machines

Alternators for Tractors and Industrial Machines
Radiators for Tractors and Industrial Machines

Driveline Components for Tractors and Industrial Machines
Starter Motors for Tractors and Industrial Machines