The speed of the left drive on my 2000 Case 1840 skid steer drive suddenly dropped off while in use. I now have about half speed on the left drive while in the forward direction, but still have equal and full speed when in reverse. The chain drives and the drive gear look fine an no spline damage. I put a load on each drive mechanism by pushing on a tree and I wasn't able to tell any difference in torque from one side to the other. Meaning the left side still had plenty of torque to spin the wheels just like the right side did. No mechanical noise or slippage to note. The linkage looks fine, the travel of the levers looks normal, the stem on the pump valve looks to be rotating in the full direction to each hard stop. Per the manual, I swapped the relief valves (front pump) from left to right side of the pump. The problem did not change nor move. Roughly 3300 hours on machine. Any suggestions? Pump, motor, or valving? Thanks in advance,
Hopefully in the linkage otherwise might be something jammed between the swash plate and stop
To the best of my ability (and others) the linkage sure seams tight and okay. Therefore I'm interested in your comment on the swash plate and stop. Any idea if that can be checked, with a pressure gauge for example or something. Or is this a pull it out and have it tore down solution. Thanks,
Don't know specifics, but check the keyway and the taper on the shaft. The swash plate shaft on the side of the pump that the linkage bolts on to. If this is a newer machine it may have a different set up. Can you take a picture of the pump and maybe the tag on it. I think it will say Sundstrand xxxxxxxxxxxx
Unfortunately I don't know what brand of pump this is. I tried taking a few pics, but its hard to get a good picture. I don't find a tag on it anywhere on it, but granted its hard to see the whole pump. I think I need to pull the cab off and inspect and clean it better. Attached pics are the best I could get. I included a pic of the side casting that had some embossed lettering in it. Don't know if that means much, but it was all I could find for identification.
The pump in the bottom of the pic is the problematic one (front pump). I need to study this more to find swash plate shaft you mention. Would it be wise to pull the spool valve and inspect?
Check items 18 and 26. Sometimes they get too much slop in them and will not stroke the pump fully. 26 is directional, so don't put it in backwards.
Follow up to my post since I found the problem. Btw, the pump is a Sundstrand, M46. I pulled the cap off the side of the pump, the cap where the valve body is. Inside I found a small flat pieced of metal. The piston valve was slamming the metal against the cover plate, preventing the valve from full travel. Since I didn't know where the metal came from I pulled the drive pump and had it gone through, basically rebuilt. I changed the oil and filter and it is now running again.