Hi everyone, this is my first post here, sorry for my language but I'm from Poland and I don't know all the technical words so I'm helping myself with a translator. I have read all the possible posts about driving problems in the Ford 555A but I have not found any matching answer and in some cases I am not sure which gearbox was mentioned. I have 4 manually shifted gears and a torque converter on my machine. I have a problem with driving, and more precisely its disappearances and problems with starting. It all started in winter, when I cleared snow from the yard, the machine was already well warmed up and when I finished my work I had problems with starting either on F or R on the steering wheel lever. The symptom was that I had to add more and more gas to make the machine move and it did it very slowly, but when the wheels started to spin, it suddenly started to accelerate strongly and go on. After changing to R, the same thing, and after a few such movements, the machine stopped completely. At first I thought that there was a short circuit, there was a lot of snow on the excavator, which started to melt from the temperature, so it was a logical explanation for me. I was away for a week and when the machine was dry it started without any problems, but I had to add a little more gas than always. Before the failure, after switching to R or F, I always felt a slight tug as a sign that a given driving mode was turned on, after 1st failure I did not feel it anymore. Not much thought, I started to work since she was driving, but after some time I had to add more gas again until it starts and she stopped in place again. I decided that I would let her rest and I would take off the next day, but for the next few days she did not want to start. I started to check the oil level, there are 2 fillers in the cabin, both the level was below. It was very problematic to find information about what oil it should be, I found several entries that the same hydraulic oil is used everywhere in the Ford 555A except for the engine. So I added this hydraulic oil to both fillers until the correct level. After pouring in the oil, I managed to move after some time, I did about 5km, it moved front and back without any problems and I got to the yard, I turned it off and after firing it there was no driving again. After finding information that there is something like a valve that throws on N (the switch in the floor and the red one in the lever on the right), it suited me that there could be a short circuit and it was causing problems. After inspecting the cables, it turned out that they were disconnected at the valve a long time ago because all the plugs are dirty (if I got it right the vlave is more or less from the bottom of the excavator in the location where the front bucket lever is). So I took off the gearbox cover to see if there were any problems there, the oil turned out to be cloudy, slightly milky (maybe there was some reaction with my oil) but I found nothing else, the gears entered without any problems with my fingers, so this is not the problem here. After careful inspection and analysis of the problem, it turns out that it is most often a problem on a warm engine and HERE THE MOST IMPORTANT, when it stops driving completely after adding gas in gear and on R / F you can hear a hissing, just like a valve open to the maximum, moving the front bucket causes the goes silent but when I stop lifting / lowering the bucket it hisses again. One more important note, after removing the gearbox cover, this part from the engine side is still spinning, even without any gear, completely in N. After engaging the gear in the air, the wheels are spinning and before the failure they did not spin. After landing it on the ground, it stands still, so there is not much turning force. And every time shifting the gear it grinds and it was not there before. Now a series of questions: 1. Is it possible to disconnect driving with too warm oil? As soon as the valve hisses, you can smell the hot oil and the box is warm to the touch, but it should work at 65 * I think. According to the instructions, the hoses go from the box to the filter and then to the radiator, maybe the filter is clogged, but would that be a problem with warm oil? 2. Does this oil in the gearbox (the part where you select gears) have any further effect on driving? But is it only for gear lubrication? 3. Is there a separate oil filler for the torque converter or something like that? The lid is under the fuel tank and I haven't taken it off yet. 4. Is there any bypass valve for the transmission? Maybe he is hissing because there is a problem with the pressure? But what would generate this pressure if it is a manual gearbox plus a clutch? Anyone have any ideas where to start? What else to check? I am asking for help
Hey Mszorek, Welcome! I have inserted a PDF file that shows the transmission. There was a design change, so it matters when yours was made. If I remember correctly, there is a round plug in the cab floor that you remove to get access to the transmission dipstick. There are a couple of others on this forum that have that same tractor, they may chime in to tell you more.
I'm going to offer some more answers to your questions later this evening. I believe I have them sorted them out in my mind. So as not to keep you wondering, I have a feeling your loss of power is due to the 555A unload valve sticking (Hissing like there's a valve open). Moving your bucket reduces oil pressure on the valve causing the hissing to cease. There's a piece of dirt or crap in the valve that is preventing valve movement and it is robbing your 555A of power. More in a bit.
I restated your questions. You will have to click on and expand them to see what I believe you are asking.
You have a problem driving in both F and R when your 555A is warm. You have to raise engine rpm higher and higher to make the machine move and it moves very slowly. Eventually it accelerates strongly, but when you switch to R, the problem repeats. Before the failure, after switching to R or F, I always felt a slight tug when your 555A changed from F to R and R to F. After the first failure, you did not feel it anymore. That tug is the shuttle clutch pack switching directions. It can also be caused by a worn linkage. When the linkage is worn, the F/R valve does not engage completely and it pops into place the rest of the way when going into F or R. If this is happening, the most likely cause is the pin on the bell crank that attaches the Main (F/R) valve to the linkage. You can see this by removing the plate under the bellhousing and watching the pin while someone is shifting between F and R. Engine off or engine on, wheels blocked. You checked the transmission oil level. It was below the full line on the dipstick. It was hard to find information about what oil to use. You added hydraulic oil to both the transmission and center housing to the full line on each dipstick. This enabled you to travel 5 km but the problem recurred after you shut the machine off. The oil you need must have a specification that meets or exceeds M2C134D. There’s a lot of Ford tractors in Western Europe and I’ve seen pictures of a few in Eastern Europe. Fendt Universal Transmission Fluid – UTTO appears to be compatible. Hydraulic oil that does not meet the M2C134A-D specification may damage the clutch packs in your transmission shuttle as well as your brakes. There is a dump valve that puts the transmission in N and you wondered if there was an electrical short engaging the solenoid in the dump valve, but the valve's solenoid was disconnected. Yes, your shuttle has a dump valve that is opened by an electrical solenoid. When open, it directs all oil to the transmission sump (gear box) and your shuttle loses oil pressure stopping F/R motion. Sounds like yours is not hooked up so this is not the problem. So I took off the gearbox cover. The oil was milky. Milky oil is evidence that there is water in your oil. If doesn’t take much water to turn the oil white. You should replace the oil in both the transmission and center housing (case behind the transmission that houses the differential) as well as the transmission filter (inside the frame behind the battery box). HERE THE MOST IMPORTANT!!! When it stops driving in gear in F or R, you can hear a hissing sound, just like a valve open to the maximum. Moving the front bucket causes the sound to cease, but when I stop lifting / lowering the bucket it hisses again. I believe your problem is caused by your unload valve sticking (deadheading) and building up excessive pressure against your hydraulic pump. The back pressure against your hydraulic pump is slowing your engine and robbing it of power which prevents it from moving F or R. Moving your loader bucket relieves the pressure off the hydraulic pump and increases engine power. The hissing you hear may be oil bypassing the stuck valve. Now a series of questions: 1. Is it possible the transmission oil is too hot. Could the filter be clogged? There is a temperature sender on your transmission. If it is working, it will light up when overheated. The filter has a bypass. When clogged, the oil bypasses the filter media. 2. Does the transmission oil in the gearbox affect F or R, or is only for gear box lubrication? The oil in your transmission powers the shuttle in front of the gearbox as well as the gearbox. It needs to be clean and free of moisture. 3. Is there a separate oil filler for the torque converter? Yes. It is under the floor, inside the frame, behind the battery box. 4. Is there any bypass valve for the transmission? Maybe there is hissing because there is a problem with the pressure? The bypass is in the filter and in the dump valve as mentioned. It is possible the hissing is coming from a valve in the oil divider (front section of the shuttle), but I’d bet on the unload valve first. If I remember correctly, one way to test the unload valve theory is to open a valve on the backhoe or loader. Keep the valve that raises the boom open and try to move F/R. If F or R movement improves with the boom valve bottomed out in the up position, your engine has more available power to move F or R and the problem is the unload valve. Test a few of these solutions and report back with the results.