Cub 125 hydrostat, reverse troubleshooting
 

My 125 pulls my plows as it should and engine is rebuilt and strong, but reverse seems to be “part-time” functioning. I have it full of new, proper hydro fluid and an IH filter. It’s behaving like I need more travel on the forward/reverse lever, or as if the swashplate isn’t traveling far enough. Rarely, it won’t back up at all. So I consulted the IH manual and I ensured brakes are properly adjusted first, then proceeded with the hystat adjustment. Reverse is stronger and no change to forward, but still intermittently performs weak in reverse. I have a dirt pile I need to spread, and I need reverse to be able to push it with my grader blade turned around. Has anyone else ever experienced this? :bigthink:

Just a quick thought I had. What condition are your relief valves? IIRC one of them is for forward and the other for reverse, there is a chance that your reverse one is starting to malfunction. This could be tested by swapping their places and seeing if forward becomes occasionally weak.

That’s a good idea, thank you! Can they be accessed without taking my tractor apart? I can see them with a flashlight if I take that rear cover piece off. The most in depth job I’ve done on mine is my K301 overhaul, I’ve never taken a tractor apart.

You could, like the IH Engineers did with the WF tractors, cut a Access Panel in the Tunnel, to gain access. Then fabricate a new cover, to cover up the cut hole.

I may be wrong here but I believe you will have to split the tractor to
access the valves. It is not as complicated as it sounds. The service manual
actually has some pretty good instructions for the project. Once in there it
will give a guy a chance to clean up lots of years of crud.
If you have rebuilt the engine this will be no problem for you.
I obviously don't have any way of knowing where your tractor budget
sits but if I was going to go that far. I would send the valves out to rebuild.
Then they are no longer part of the equation.

Ken

Is there a source on this forum that we can send the relief valves to? Are new ones available from Sundstrand?

Machtech Direct
605 Furnace Rd.
Conneaut Ohio 44030
Phone: 440-499-5813
Email: mark.machtech@gmail.com

Mark is awesome to work with. Send him the valves and a week later
they come back. I think they are around $80 a piece, to do.

Ken

Thank you West Valley

Just pondering through other reasons for your reverse issues. :bigthink:
Does your lever controlling forward and reverse have full travel?

I think if it were me I would do a study of linkages and anything that pivots.
Start at the hydro lever and go to the hydro and lube it all. It is amazing
what some maintenance will change. And if you do that and still have troubles
you can start tearing into things. And besides, then things will be all lubed
up and ready to go.

Ken

Like Ken said, start with the lube, charts, simple things. I would pull deck, put safely up on jack stands. That way I could lube, crawl under, get a helper to move pedal, linkage, forward, backward, try to figure out before breaking apart. Cubs that sit will do this kind of thing. When I get it so pushing pedal down gets lever to easily jump into neutral, then start tractor to confirm. Good luck.