I have an old 621ZF (JAK0022100) with the 4WG-150 / 4642054014 transmission and I keep randomly getting a 2-second audible alarm with no warning lights and no noticeable loss of performance when it happens. Some days, it runs all day with no alarms, and some days it happens shortly after startup. I am wondering if anyone can help me identify what is going on with the limited information below. Repair guys can't make it out for 3-4 weeks and I need to get it fixed if possible. No working gauges in the cab but I don't believe anything is overheating. If I start getting the alarm, I let it idle for a few minutes, turn it off and let it sit for an hour or more. Usually, I get the alarm again within a minute after startup. Noticed a small amount of transmission fluid on the ground under it this morning for the first time since I started running it. It appears to be coming from the bottom of the suction tube where it connects to the housing, but it doesn't leak all the time. After adding a little fluid to correct the levels and driving around the lot a few times everything seemed fine. As soon as I started actually working with it a couple of minutes later, I started getting the alarm again and immediately checked for any leaks. Nothing. Levels were good and it drove fine. Today, I would only get an alarm after shifting from reverse to drive (in both 1st and 2nd gears) and giving it throttle to start moving AND only after picking up a load or dumping a load. It would never do it by simply driving in reverse and then stopping and going forward or doing the same thing with an empty bucket. Only if I actually scooped or dumped a load. If I immediately stopped for a second then started moving again, it wouldn't go off again until I picked up/dumped a load then shifted from reverse to drive. If I just kept rolling through the alarm, I would get a second alarm immediately after the first. Had remote control valve rebuilt and had to replace 2 hydraulic hoses directly under the remote valve this week due to leaks. I don't know if they have always leaked, just started leaking, or if hoses started leaking after valve rebuild as I just started running this machine. I just know there are no more hydraulic leaks now and the hydraulic fluid levels are good. Doing a stall test is going to be tough. After reading the service manual, the RPM's are read off of the flywheel teeth. This machine is missing teeth and I have to turn the engine and try to start it a couple of times before the starter catches and starts it up. Flywheel got messed up after a mechanic did a sorry job on replacing the starter and didn't bother to shim it properly. I know it is a long shot, but I figured it was worth a try to ask. Any help is appreciated.
Hi DHaze, the only thing I can imagine is the pressure gauge for modulated pressure on t/m control valve. The modulated pressure drops for 1 to 2 seconds during gear change to enable smoother torque takeover of new clutch. In 1st usually a bit longer, 2-4 faster. Case might have fitted a halfway intelligent gauge counting the time of low pressure, throwing a code when exceeding threshold. Modulated pressure is a the port in center of control valve, usually the unique port connected to a gauge. M10x1 thread. What happens when disconnecting gauge completely? (Plug port)
I would start by getting all the dash warning lights working. Thats really the only way you know why your getting the alarm. It sounds like you can make the alarm happen with a full bucket while shifting. Will it do it every time? Go through the electrical section on warning lights. around page 443 and 359. the only warnings are engine oil pressure, air pressure, auxilary steering, engine coolant temp, parking brake while in gear, alternator, trans temp, and hyd temp. master warning is controlled by the instrument cluster. It may be as simple as the instrument panel not working causing the issue. You can test sensors before instrument cluster and confirm they all are working. Also take temp readings of trans and hydraulic. It could be a faulty temp sensor. You could work through sensors info is on 359. Your going into this blind with out cluster working. maybe start at trans temp. while its alarming unplug temp sensor and measure temp. Did you bring this to a case dealer?
Thanks for the help. The Case dealer in my area wanted almost $600+ mechanic time just to come take a look at it, but I found a heavy equipment repair place that came highly recommended. I will just have to wait a couple of weeks before they can make it out. I appreciate all the help. I will do what I can and report back in case anyone else runs into something like this in the future.