I have a Deere 550G Dozer (serial# T0550GH800161). A long spring broke in the linkage system for the hand throttle and now the machine wants to run wide open throttle unless the decelerator is held down. I can move the throttle lever to low idle but when remove my hand it goes to WOT. I have bent the spring where it broke and tried to reattach to the lever but the geometry of the spring angle interferes with the transmission shift linkage. Does anyone have this same machine and can pull the cover and send a pic of how it is set up? I also looked on Deere's parts website and could not find the correct diagram or part number for a new spring. See photos, thank you in advance.
I have the same dozer at home. I have a pretty busy evening right after work, but I will try to get a picture of it as soon as I can. I also looked at the parts diagram and you are correct, it doesn't show a spring there. Do you have spring #19 at the other end of the cable? Is there any chance it could of broke from there and flung its way to where it is in your picture?
@JBrady has you on the right track. The broken spring you show in the picture is for the transmission controls when in “Park” . See (2) screenshots below. .
JBrady, thank you for looking when you get a chance. Diesel Dave, I guess I have two issues then. I will remove the floor plates and look for the #19 spring that JBrady shows in his diagram to diagnose/fix my initial issue. The extension spring #17 you show is definitely the one that is broken in my photo as it is still tied to the floor plate.
Take off the left engine side shield to check spring # 19 that JBrady was referring to.
So I figured it out. The long broke spring #17 is its own issue that I reconnected and can’t tell a difference it made to the shift linkage. #19 spring was good. The issue was the tension adjustment was too loose at the throttle lever itself, I tightened up the Allen bolt (shown in my picture) and all is good. This makes sense now because for a while when I would let the machine warm up and idle it would slowly increase rpm without input, the vibration and loose tension was letting the throttle lever slip and must have become loose enough to have no tension at all. When I went to diagnose it the broke spring threw me off. Thanks for the input, it helped me get to the solution.
That's great information to know about the tension screw. I didn't know that was there. We got 4.5" of rain last night and I never made it to where the dozer was parked. A couple of times ago that I was working the dozer, I thought I noticed the RPMs change on their own too. I inspected the spring and linkage and it all looked good. It was Diesel Dave that helped me get a screenshot for how to check the decelerator pedal/cable adjustment. This has been a really helpful forum for me over the last several years.