I bought a 955 with hydrostatic transmission that runs but will not move. Has hydraulic pressure for lift and remotes, but the tractor itself will not even try to move. Guessing it is a bad pump in transmission. Anybody have any suggestions as to what might be the problem and how to remedy it? Any experiences would be greatly appreciated.
955 runs but will not move
- Thread starter ncfarmboy
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Mechanos
Veteran Member
Dumb question, but is the parking brake set. Is it in gear or in neutral? Hey, somebody had to ask so I figured I'd get it out of the way.
beenthere
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ncfarmboy
:welcome:
Tell us more, as the brief description doesn't give much to go on. Some history of where you bought it, how did it get to where it "won't move" (roll it off a truck? or? ). A bit about your experience with tractors and hydrostatic to know where to start with answers or questions will help.
Do you have the manual?
I wouldn't guess it is a bad pump in transmission, and wonder why you are guessing that. Do you know where the hyd. pumps are located? A lot of things this could be, and the more likely is the tranny is in neutral. But more info is necessary to help here.
:welcome:
Tell us more, as the brief description doesn't give much to go on. Some history of where you bought it, how did it get to where it "won't move" (roll it off a truck? or? ). A bit about your experience with tractors and hydrostatic to know where to start with answers or questions will help.
Do you have the manual?
I wouldn't guess it is a bad pump in transmission, and wonder why you are guessing that. Do you know where the hyd. pumps are located? A lot of things this could be, and the more likely is the tranny is in neutral. But more info is necessary to help here.
I'm a farmer and picked this up from a landscaper to use around the farm and my wife's veterinary clinic doing small jobs. Landscaper said it drove itself into place and when he went back to it awhile later, it wouldn't move. It's been sitting close to a year now. Parking brake checked and it's not in neutral. Deere mechanic said sometimes the dump valve gets stuck open causing this problem and have not gotten around to finding and checking that yet. As for suspicion of pump problem, when you try to go forward or backward by pressing pedal either direction, there is no change in noise, engine shows no signs of being put under even a slight load and there is absolutely no movement, vibration or anything.
caseyvand
Bronze Member
Hi.....Does this tractor have a transmission bypass valve?
No one has asked, so I will. Is the linkage from pedals all connected and hydro control lever is moving with linkage? If so, then the most frequent thing I have seen is the output gear on hydro shears off the retaining bolt which allows the gear to slide off of shaft. Check out items 58, 59, and 60 on diagram. The hydro will need to be removed from the front of the transaxle to verify this. If bolt breaks, the bolt head and washer falls down into transaxle and is very difficult to remove without removing transaxle from frame and then removing the front cover to retrive broken bolt and washer. On rare occasion, they can be fished out with a magnet.
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Mechanos
Veteran Member
Ah yes... I had forgotten that the early units used a bolt to retain that drive gear... and yes it is a fairly common problem for that bolt head to break off. The late units used a threaded shaft with a castle nut to retain the gear.
Kevin M
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No one mentioned to check the seat safety switch . Look under the seat couple of switches there that could be holding you up. Try the simple stuff first before you go tearing things apart. Keep us posted , I'm tuned in !
Kevin M
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Does the PTO operate ? With the age of these tractors the electrical system get corroded and brittle.
Mechanos
Veteran Member
The only thing the seat switch controls on a 955 is the PTO. Everything else is done with mechanical linkage or hydraulic circuits. It's one of the last "mechaical" JD compact tractors.
If the bolt on the hydro trans output shaft is broken off and the drive gear allowed to walk enough to disengage from the driven gear, then everything else will continue to work on the tractor. It just won't move under it's own power.
If the bolt on the hydro trans output shaft is broken off and the drive gear allowed to walk enough to disengage from the driven gear, then everything else will continue to work on the tractor. It just won't move under it's own power.
Kevin M
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- 48" bobcat walk behind , 60" Dixie Chopper Classic , 755 John Deere 4x4 70 ldr belly mower etc etc , 7610 Ford 4x4 7412 ldr and 10 ft rhino hogg
I assumed that my 755 and the 955 were similar, My 755 has a rod that come up up the seat and needs down pressure ( My big *** ) to push it down before the tractor moves. Thanks for clarifying.
Mechanos
Veteran Member
That rod is connected to a linkage that keeps you from moving the pedals... aka mechanical interlock.
Ok. So I looked at tractor again and rechecked everything I had checked awhile back, still to no avail. PTO operates, remotes work, lift works, but will not turn axle at all. When you press forward or reverse petal, there is a slight hissing, but nothing more. All linkage is connected and moving the shaft going into the side of the pump. I did remember that the previous owner told me the last job the tractor was doing was pumping out a small pond using a gator pump (large volume, pto-driven). Bolt head could have sheared while unattended. After gear comes loose, would there be a tell-tale noise that it would continue to make? Thanks for all the help guys!
The bolt would not break when using pto only. It holds the gear on hydro shaft for ground drive only. Usually the bolt would brake when trying to back up. That is when the gear would put thrust on the bolt. Sometimes if tractor front is pointed down hill, the gear will slide back on shaft far enough to drive forward.
MarkVallon
New member
Hi there. I hope someone still reads this. I have a similsr situation. The tractor will move forward, but when backing it will stop after a couple of feet and sound like it's grinding gears. Driving forward is fine until I let off the forward pedal and coast, in which case it feels like I've pushed in the clutch and again makes a grinding sound. . I've looked through the drawings in the manual and your post. Is it possible, that the bolt head has sheared off and that the thrust loads are pushing it to disengage in reverse and pulling it back in going forward? You write as if this is a fairly common event in these tractors. Any help would be appreciated. Thanks!
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