Loosing what little hair I have left. Few weeks ago 580D lost forward, reverse was still strong. Shop guy at Case said it was probably clutch pack, so I ordered a whole clutch/seal/bearing kit online, and ordered a new charge pump from case. Went through the whole, thing, changed everything out, and now that I have it back in, I don't have anything, no forward, no reverse, no pressure on the top test port. Do have 25+ PSI on the side adapter test port. Took it out, checked the spacing between the bottom plate and snap ring on the forward clutch, put a thinner ring to give it a little more clearance. Put it back in, still nothing. Took the control spool out, made sure everything was moving freely, made sure the plunger is pushed in. Still don't have anything. I'm lost and don't know what to look at next. It is spinning in the reverse direction when you put it in forward and reverse with the back wheels off the ground, but doesn't have enough go with them on the ground to spin. Anybody have any suggestions? I wondered if a clutch pack was hung or fighting each other, but I don't know what i would have wrong to cause that. Only thing I didn't do was replace the Torque converter, but I figured if i had reverse when this all started that it was working fine?? Thank anybody in advance who has any ideas. Carl
I don't like the no pressure at the #1 test port, Are you sure the lever on the shuttle spool that changes from F/R is on correct and not 180 turned around. The oil comes from the charge pump to the valve and is regulated there for lube/pressure. I would slip the valve out again and remove the pins/snap ring and take it apart, use caution with the snap ring side its under some pressure (I use a small arbor press) to push it down to get the snap out and to release the pressure. You could have sent a little bit of trash through the valve. Reinstall and check. Then you are back to square one to remove the shuttle again slip it apart to see if you have any seals cut and to take a look at the charge pump. I trust you have a service book to go by.
I agree with Sheepfoot. In the control valve there is the internal valve which the external plunger pushes against. If you remove the cut out solenoid, & depress the plunger, you should feel it make contact with with the internal dump valve about half way down & continue to full depression (no pun intended). If it pushes smoothly down without moving the internal valve - it is stuck in the dump/ neutral position. They will often free up if you remove the plunger & depress the plunger using a screwdriver with some clean solvent & then clean oil for lube. If the plunger is OK - you will need to remove the shuttle again & check seals - particularly the small teflon ones at the bottom of the mainshaft - they are very easy to damage during install.
First, thank you gentlemen, and yes sheepfoot, first thing i bought when the problem arose, was the service manual, figured my wife will never let me buy another backhoe, might as well be able to work on this one. I have the thing out for the third time now. I pulled the shuttle spool in between the second and third time to run through it again. Alrman, you hit on one thing, i just found pulling it the third time, i did mess up the two little seals on the shaft where it bottoms out in the pinion gears. On the subject of the spool valve, sheepfoot, I'm pretty sure it's at least in the right direction, when it's in the housing and in neutral, one of the holes on the spool lines up with a hole in the casting. One thing i couldn't figure out when i just pulled the control spool, (and I ordered all new springs for the thing just to be sure), was that the part that case calls a "expansion plug" that the pressure regulator piston sits up against was bowed up toward the piston, it seemed to me that it would be flat, but i wasn't sure. Since i've got the whole shuttle out again, i'm going to go pull the spool valve and see if i can find anything. Either of you gentlemen think i should replace the torque converter just to be safe?
Roll them 2 small fibre seals up small and grease the grooves up with a good tacky grease to stick them in the grooves, unroll them and install them working them back into the grooves. stand the shuttle up so shaft can be dropped straight in and install. I suppose everyone has had the same thing happen once that has rebuilt them. What do they say about experience..........................
Sheepfoot and Alrman and Melben, I must thank you gentlemen, I'd have thrown in the towel if not for your suggestions. the grease and rolling up the seals helped, I also installed the main shaft in the pinion gears outside of the housing so i could make sure i wasn't messing up there. I'm pretty sure the culprit ended up being what case calls an expansion plug in the control valve. Little piece between the pressure regulator and the spool. The new one i got in was domed and completely sealed off the opening once i beat it in, my old one looked more like a saddle. Would have never thought it to be wrong till the suggestions of it being in the control valve. Thank you again.