Case 580B (1974) Hand Throttle Not Working

[Mike Hupka]

Hi All, thanks in advance for any advice you can provide. The hand throttle in my '74 580B does not work. Its hard to move and there is no change in RPM when you force it a bit. I was looking online at a diagram and it looks like the bracket the hand throttle attaches (#2) to points up.




However, in the photo you can see mine points down.



Naturally, if mine is in the wrong position I could see why it makes no difference when I move it. Before I tear into this and try and get that thing to point up does anyone have a better idea of how to troubleshoot this the right way? It's my first piece of equipment and its been a fun learning curve so far.

 

[Tinkerer]

Before you try to change the position of the arm, remove the linkage from it.
Then try to move the hand throttle.
It maybe bound up from a lack of lubrication.
If it isn't bound up, find which way the disconnected linkage has to move to get the IP to move from idle to WOT.
My guess is that you will be changing the position of that arm to like it is shown in the parts book.

 

[Mike Hupka]

Before you try to change the position of the arm, remove the linkage from it.
Then try to move the hand throttle.
It maybe bound up from a lack of lubrication.
If it isn't bound up, find which way the disconnected linkage has to move to get the IP to move from idle to WOT.
My guess is that you will be changing the position of that arm to like it is shown in the parts book.

This is good advice, I appreciate it. I'm going to try this out tomorrow and see if it pans out. Thanks for posting!

 

[Mike Hupka]

Hi All,

I wanted to post a reply/update to this in case anyone else can ever benefit. The problem we were experiencing looks as though it was caused by another issue that needed to be repaired as well.

The bracket I refer to above does indeed need to point up. However, one of the metal hard lines for the steering system was in the way. Upon further inspection, the hard line itself was bent down farther than it should be from the weight of the fuel tank which was pressed hard against it. I was able to lift the tank a little (after I took the fuel out) so there was some play there. The fuel tank bracket on the front sagged down a bit so I thought that might have made the tank lower itself. The steering column also had a ton of play in it (not sure if this contributed to the issue but it was pretty bad. The bolt holding it down on the driver's side was about 1/2" out and just spun in both directions. I pulled the fuel tank out (that's a project for someone without much experience) and started fixing the column and then the bracket. I also noticed that I had plenty of space above the tank so I installed new bushings under it and added a 1/2" spacer bushing. The bracket for the hand throttle immediately popped up into the correct position when I pushed on it a bit and worked as expected. When I put everything back together (after a little paint and rust work) it runs like a champ. I have maybe 25 hours on it since I finished that work and so far no trouble.

Thanks for the advice and good luck to anyone who has to pull their fuel tank. That was a pain for an amateur. I'm sure there are experienced operators that can knock that out in no time but I was cursing more than a little, haha.

You can see in this image, with the tank out and the hard line moved slightly, the hand throttle bracket operates just fine.

This is completely unrelated but since I had the tank out I gave it a coat of paint and figured I might as well treat the rest of the machine to a little something so I started with the cab forward. I'll get to the rest this fall.



Obviously, it's not a high-quality job but it'll help me get a few more years out of the machine and my wife isn't as upset about it being parked where people might see it when it looks presentable.

 

[Roger1462!]

Thank you thank you thank you, I had the exact same problem and while reviewing parts list I never clued into the mechanism in the up position

I found your post and followed up on my machine this morning and low and behold mine was down also

I removed the linkage inside steering column and lengthened it, put the dog up and now everything runs like a charm!!

Again thanks for posting this appreciate it!

Roger

 

[Mike Hupka]

Thank you thank you thank you, I had the exact same problem and while reviewing parts list I never clued into the mechanism in the up position

I found your post and followed up on my machine this morning and low and behold mine was down also

I removed the linkage inside steering column and lengthened it, put the dog up and now everything runs like a charm!!

Again thanks for posting this appreciate it!

Roger

Thats great! I'm glad it helped out. I've been chiselling away at problems since I bought this (first piece of equipment I've ever owned) but it's been fun. The service manual has been extremely useful for problems like this one. I still have a long way to go:
- none of my gauges work
- 3 cylinders are leaking significantly
- cab rust needs to be dealt with
- one rear tire is so dry rotted I fear its going to give out any time now, haha. Hoping I can find a used one somewhere or some sort of "budget friendly" option. It feels unlikely.
- The seat is almost down to just the metal plate. That will likely need to get fixed pretty soon.