Our Case 850g dozer has developed a new issue. the right track does not operate forward or back in any either range. It apparently had happened very intermittently the past month or so. It would be running fine then the right side would stop for a minute but start rolling again. the left side track has no issue. the right side stopped working and is not correcting itself. the machine was low on fluid, a couple of quarts. i installed new filter and brought up oil level. still no function on right side. left working. checked the linkages from lever to unit on top of tranny. no binding and the travel is sufficient. i can feel the shift go into detent. i really do not know what to look at or suspect at this point. one last thing, while driving it back to barn, on left track only, a couple of times i could feel the right hand track start working for a few seconds but then go dead. any advice will be greatly appreciated
Im not as well versed in the Cases' but Deere had "speed sensors" and it would cause the same issue when damaged or "going out" machine would just spin in circles.
I'm not sure if this dozer has those kind of electrics. I'm checking into that as we speak. This machine uses hand levers and two brake pedals for motion. We have a John Deere with joystick control. That thing has all kinds of sensors. That would simplify the remedy if this Case uses sensors')
Older unit? I’ve messed with a few older cats that have to 2 pedals on the floor with the brake adjusters on the seat. Possible brake failure?
There is a number of things that can go wrong to cause this. A test gauge & various fittings will be required to test the transmission pressure. Some models had a quick release fitting factory fitted at the transmission filter for basic pressure testing which will be a start. To begin, you will need to test system pressure in neutral & then see the difference in pressure when you select each range - comparing LH & RH. Then I would disconnect the lines going to high/low & compare what pressure is coming out of the valve - without the clutch packs connected. This will tell you if it has a pressure problem in the valve (supply pressure) OR if there is leakage in the clutch pack / range shaft seal ring area. The control valve on the 850G, uses spools that contain valves/springs/ball bearing check/shuttle valves - these can be the cause if correct pressure is not being sent to the RH clutch packs. If these are suspect, you can remove the rear cover of the control valve & swap the LH & RH range spools & see if the problem moves to the LHS. There are also neutralising spools in the control valve connected to the brake pedals - well worth investigating. Unfortunately, there is no 'easy' fix in this type of problem & a good understanding of how the transmission works is required - a service manual will help.
I figured it would be getting deep into the workings of the transmission. It may be time to call in the A team. I am not tooled up for checking pressures etc. Getting a shop manual sounds prudent. Thank you for the heads up.
I have the same machine that’s experiencing the same problem. Did you ever find out what was the problem?