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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Default 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
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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).
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Default 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
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Wayne Cook fired this volley in
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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
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Default was "Tow behind".switch to JD estate tractor

"Pete C." fired this volley in
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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

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Default 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.



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Default 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).
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Default 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
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Default 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

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Default 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
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Default 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


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Default 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. :-)
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Default 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
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Default JD estate tractor, discovery

Leon Fisk fired this volley in
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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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