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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
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was "Tow behind".switch to JD estate tractor
On Mon, 27 Aug 2007 15:07:09 -0000, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote: Ignoramus19946 fired this volley in m: There is a local opportunity to buy a used, name brand tow behind generator that is not working as follows: the engine (4 cyl. White diesel) is running fine, the generator is not making any output. I was gifted a nice but non-functional JD estate tractor. 32HP diesel with all hydrostatic stuff. The engine runs fine, although I think it's going to need an injector pump rebuild... stumbles a bit at high speed. BUT... although every hydraulic accessory on it works perfectly - lift, blade PTO, accessory PTO, everything - the traction drive will turn the wheels under no load, but won't move the tractor. You get a little minor "oommph!" out of it when you attempt to drive, but it won't move in either forward or reverse. I noticed that someone had butchered the (very expensive) "neutral" valves because they were leaking. Thinking this was the problem, I removed both, replaced o-rings, etc, and _think_ I've made sure the valves are in the "closed" position (basically welded shut). Anyone seen this problem? It seems like the pressure is being bypassed around the traction motor somehow... and the neutral valves still seem to me like they'd be at the heart of it. Very Very common problem unfortunately. The newer John Deere hydrostats are bad this way. They don't have a oil filter and people don't change the oil often enough to prevent this. First off a lesson in hydrostatic drives. First step is that the oil from the axle is picked up and pumped to about 500 psi by the lift pump (a gearotor type pump on the older units). This pump provides the power for the accessories and provides oil to the main hydrostatic drive pump. (thus the reason you've got power). Next step the oil is pumped by a variable displacement pump. This is likely where your problem is. The variable displacement pump looks kind of like a the cylinder in a revolver. The cylinder revolves against a valve plate on the front end. It has pistons that are lapped to fit it that free float in the cylinder (the reason for the charge pump is to push the pistons back). The back end of the pistons have feet kind of like what's on the end of the screw of a C-clamp. These feet ride on a "swash plate". The swash plate is controlled by the "gear shift" so the when you're in neutral it's flat and the pistons don't move. When you want to go forward you tilt the swash plate one way and for reverse you tilt it the other way. The usual failure mode of these pumps is that the face of the cylinder and the valve plate get grooves cut in them from dirt in the fluid. Once this happens the oil leaks past and the pump can't build up any pressure. From everything that I've heard there are no replacement parts available for the newer John Deere pumps. I was able to get a new valve plate and I lapped the face of the cylinder on my old (pre 1970) John Deere hydrostatic mower. But that was about 18 years ago when I did it. Since this is a metalworking group it's likely that you've got the skills and equipment to repair the valve plate and cylinder (I didn't have any machines except a drill press back when I repaired my old mower). From what you're saying I think that you're hydraulic motor is still in good shape (common). |
#2
Posted to rec.crafts.metalworking
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was "Tow behind".switch to JD estate tractor
Wayne Cook wrote:
On Mon, 27 Aug 2007 15:07:09 -0000, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: Ignoramus19946 fired this volley in m: There is a local opportunity to buy a used, name brand tow behind generator that is not working as follows: the engine (4 cyl. White diesel) is running fine, the generator is not making any output. I was gifted a nice but non-functional JD estate tractor. 32HP diesel with all hydrostatic stuff. The engine runs fine, although I think it's going to need an injector pump rebuild... stumbles a bit at high speed. BUT... although every hydraulic accessory on it works perfectly - lift, blade PTO, accessory PTO, everything - the traction drive will turn the wheels under no load, but won't move the tractor. You get a little minor "oommph!" out of it when you attempt to drive, but it won't move in either forward or reverse. I noticed that someone had butchered the (very expensive) "neutral" valves because they were leaking. Thinking this was the problem, I removed both, replaced o-rings, etc, and _think_ I've made sure the valves are in the "closed" position (basically welded shut). Anyone seen this problem? It seems like the pressure is being bypassed around the traction motor somehow... and the neutral valves still seem to me like they'd be at the heart of it. Very Very common problem unfortunately. The newer John Deere hydrostats are bad this way. They don't have a oil filter and people don't change the oil often enough to prevent this. First off a lesson in hydrostatic drives. First step is that the oil from the axle is picked up and pumped to about 500 psi by the lift pump (a gearotor type pump on the older units). This pump provides the power for the accessories and provides oil to the main hydrostatic drive pump. (thus the reason you've got power). Next step the oil is pumped by a variable displacement pump. This is likely where your problem is. The variable displacement pump looks kind of like a the cylinder in a revolver. The cylinder revolves against a valve plate on the front end. It has pistons that are lapped to fit it that free float in the cylinder (the reason for the charge pump is to push the pistons back). The back end of the pistons have feet kind of like what's on the end of the screw of a C-clamp. These feet ride on a "swash plate". The swash plate is controlled by the "gear shift" so the when you're in neutral it's flat and the pistons don't move. When you want to go forward you tilt the swash plate one way and for reverse you tilt it the other way. The usual failure mode of these pumps is that the face of the cylinder and the valve plate get grooves cut in them from dirt in the fluid. Once this happens the oil leaks past and the pump can't build up any pressure. From everything that I've heard there are no replacement parts available for the newer John Deere pumps. I was able to get a new valve plate and I lapped the face of the cylinder on my old (pre 1970) John Deere hydrostatic mower. But that was about 18 years ago when I did it. Since this is a metalworking group it's likely that you've got the skills and equipment to repair the valve plate and cylinder (I didn't have any machines except a drill press back when I repaired my old mower). From what you're saying I think that you're hydraulic motor is still in good shape (common). JD builds hydraulic systems without filters???!!! My opinion of JD just fell precipitously |
#3
Posted to rec.crafts.metalworking
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was "Tow behind".switch to JD estate tractor
Wayne Cook fired this volley in
news The usual failure mode of these pumps is that the face of the cylinder and the valve plate get grooves cut in them from dirt in the fluid. Once this happens the oil leaks past and the pump can't build up any pressure. Thanks, that's good information. LLoyd |
#4
Posted to rec.crafts.metalworking
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was "Tow behind".switch to JD estate tractor
"Pete C." fired this volley in
: JD builds hydraulic systems without filters???!!! My opinion of JD just fell precipitously Just for the record, this system does have an hydraulic fluid filter. I didn't check the nameplate, but believe this tractor was built in 1998. It's got boucoup hours on the Hobbs, but except for the traction drive, still does everything else properly. LLoyd |
#5
Posted to rec.crafts.metalworking
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was "Tow behind".switch to JD estate tractor
On Tue, 28 Aug 2007 00:27:01 GMT, "Pete C."
wrote: JD builds hydraulic systems without filters???!!! My opinion of JD just fell precipitously Agreed! My neighbor just got a new John Deere mower. I bought his old one. While looking over the new one we discussed this problem. I know of another JD that has been offered to me for free if I'll come and get it with the same problem. |
#6
Posted to rec.crafts.metalworking
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was "Tow behind".switch to JD estate tractor
On Tue, 28 Aug 2007 17:34:37 -0000, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote: "Pete C." fired this volley in : JD builds hydraulic systems without filters???!!! My opinion of JD just fell precipitously Just for the record, this system does have an hydraulic fluid filter. I didn't check the nameplate, but believe this tractor was built in 1998. It's got boucoup hours on the Hobbs, but except for the traction drive, still does everything else properly. OK. That's much better IMHO. You might even be able to get parts for it (though I wouldn't hold my breath now days). |
#7
Posted to rec.crafts.metalworking
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JD estate tractor, discovery
Well, I feel dumb!
The old fellow who gave me the tractor said it was an LT350, and gave me an operator's manual for a 350. Last night, I deemed it "time" to pull the transaxle, which is a fairly simple but fussy job. By the time I'd gotten 10 years of oily grass mat stripped off everything, it became apparent that this was a John Deere 455 tractor. It's not 32HP, it's 22, but it runs a 60" belly mower through knee high grass like it was 50HP. The tranny is a Tuff Torq unit. I haven't yet uncovered any nomenclature on the transaxle that will show me a model number. I THINK I noticed some wiggle in the F/R linkage D-shaft connection. One of the original respondents might be right -- this might just be a linkage problem. But the tranny won't keep a load of oil... every gasket leaks. So it's time to get it out and fix everything in one pass. Now that I actually know the model, any schematics floating around out there? blush LLoyd |
#8
Posted to rec.crafts.metalworking
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JD estate tractor, discovery
On Wed, 29 Aug 2007 11:35:01 -0000, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote: Well, I feel dumb! The old fellow who gave me the tractor said it was an LT350, and gave me an operator's manual for a 350. Last night, I deemed it "time" to pull the transaxle, which is a fairly simple but fussy job. By the time I'd gotten 10 years of oily grass mat stripped off everything, it became apparent that this was a John Deere 455 tractor. It's not 32HP, it's 22, but it runs a 60" belly mower through knee high grass like it was 50HP. The tranny is a Tuff Torq unit. I haven't yet uncovered any nomenclature on the transaxle that will show me a model number. I THINK I noticed some wiggle in the F/R linkage D-shaft connection. One of the original respondents might be right -- this might just be a linkage problem. But the tranny won't keep a load of oil... every gasket leaks. So it's time to get it out and fix everything in one pass. Now that I actually know the model, any schematics floating around out there? Looks like you're in luck. From looking at John Deere's parts catalog they have parts available for that transmission. Try looking here http://jdpc.deere.com/jdpc/servlet/c... geServlet_Alt |
#9
Posted to rec.crafts.metalworking
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JD estate tractor, discovery
Wayne Cook fired this volley in
: On Wed, 29 Aug 2007 11:35:01 -0000, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: Well, I feel dumb! The old fellow who gave me the tractor said it was an LT350, and gave me an operator's manual for a 350. Last night, I deemed it "time" to pull the transaxle, which is a fairly simple but fussy job. By the time I'd gotten 10 years of oily grass mat stripped off everything, it became apparent that this was a John Deere 455 tractor. It's not 32HP, it's 22, but it runs a 60" belly mower through knee high grass like it was 50HP. The tranny is a Tuff Torq unit. I haven't yet uncovered any nomenclature on the transaxle that will show me a model number. I THINK I noticed some wiggle in the F/R linkage D-shaft connection. One of the original respondents might be right -- this might just be a linkage problem. But the tranny won't keep a load of oil... every gasket leaks. So it's time to get it out and fix everything in one pass. Now that I actually know the model, any schematics floating around out there? Looks like you're in luck. From looking at John Deere's parts catalog they have parts available for that transmission. Try looking here http://jdpc.deere.com/jdpc/servlet/c...catalog.view.s ervlets.HomePageServlet_Alt Yep, I have the exploded parts drawings downloaded from that site, but no hydraulic schematic. This will probably turn out to be a "real" metalworking project. The two "neutral" valves the fellow destroyed to cure a leak cost roughly $490 to replace. Seems like I'll be making some on the lathe, charging my time at minimum-labor rates G. LLoyd |
#10
Posted to rec.crafts.metalworking
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JD estate tractor, discovery
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote:
This will probably turn out to be a "real" metalworking project. The two "neutral" valves the fellow destroyed to cure a leak cost roughly $490 to replace. Seems like I'll be making some on the lathe, charging my time at minimum-labor rates G. Just be happy knowing you are part of the small community that can actually make stuff and fix chit. Wes |
#11
Posted to rec.crafts.metalworking
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JD estate tractor, discovery
On Wed, 29 Aug 2007 14:43:38 -0000, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote: Wayne Cook fired this volley in : On Wed, 29 Aug 2007 11:35:01 -0000, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: Well, I feel dumb! The old fellow who gave me the tractor said it was an LT350, and gave me an operator's manual for a 350. Last night, I deemed it "time" to pull the transaxle, which is a fairly simple but fussy job. By the time I'd gotten 10 years of oily grass mat stripped off everything, it became apparent that this was a John Deere 455 tractor. It's not 32HP, it's 22, but it runs a 60" belly mower through knee high grass like it was 50HP. The tranny is a Tuff Torq unit. I haven't yet uncovered any nomenclature on the transaxle that will show me a model number. I THINK I noticed some wiggle in the F/R linkage D-shaft connection. One of the original respondents might be right -- this might just be a linkage problem. But the tranny won't keep a load of oil... every gasket leaks. So it's time to get it out and fix everything in one pass. Now that I actually know the model, any schematics floating around out there? Looks like you're in luck. From looking at John Deere's parts catalog they have parts available for that transmission. Try looking here http://jdpc.deere.com/jdpc/servlet/c...catalog.view.s ervlets.HomePageServlet_Alt Yep, I have the exploded parts drawings downloaded from that site, but no hydraulic schematic. Unfortunately the best I can do is scan the schematics for my old 140. I'm sure they're similar but definitely not exact. This will probably turn out to be a "real" metalworking project. The two "neutral" valves the fellow destroyed to cure a leak cost roughly $490 to replace. Seems like I'll be making some on the lathe, charging my time at minimum-labor rates G. Yep. It's nice to be able to make stuff. :-) |
#12
Posted to rec.crafts.metalworking
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JD estate tractor, discovery
On Wed, 29 Aug 2007 14:43:38 -0000, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote: Yep, I have the exploded parts drawings downloaded from that site, but no hydraulic schematic. This will probably turn out to be a "real" metalworking project. The two "neutral" valves the fellow destroyed to cure a leak cost roughly $490 to replace. Seems like I'll be making some on the lathe, charging my time at minimum-labor rates G. Hi LLoyd, Maybe Tuff-Torq's website will help? See: http://www.tufftorqservices.com/isro...ting/index.htm I started to download the manual for the K61 tranny (it started to give it to me) but it is over 12mb and a bit much for just some curiosity via dial-up -- Leon Fisk Grand Rapids MI/Zone 5b Remove no.spam for email |
#13
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JD estate tractor, discovery
Leon Fisk fired this volley in
: http://www.tufftorqservices.com/isro...leshooting/ind ex.htm I was on there earlier, and mentally gave up when none of the trannies in the selector wizard were near mine. But that link was magic. THANKS! If not identical, the K92 tranny is so close, I cannot see the differences. It must be out of production; it's certainly not in any of the categories offered in the selector. Well... now I'm a bit more worried about what will need fixin'. There are two pumps and two distinct circuits -- one for all the "other stuff", and one for the traction drive... sigh.... If it's the hydrostatic pump or motor, it'll be expensive. If it's just a check valve or restricter oriface, or a leaking seal between circuit elements (lots of big, flat gaskets with high and low pressure galleries adjacent to one-another in that bugger) I can fix it myself. LLoyd |
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