I had a messy but fun time pulling the Tuff Torq tranny off that old
JD455.

I've been working on the assumption that the shade-tree guy who welded
the tow valves shut actually caused the "no reverse" problem it has.
Now, I'm pretty convinced.

There were a couple of case leaks, so that offered an opportunity to peek
inside with good reason. But when I got the case open, I was completely
amazed.

This thing has 3K hours of actual mowing on it. There wasn't enough
swarf inside the case to dirty one fingertip! If I didn't mind the taste
of ATF, I could've eaten out of it.

Now I'm completely convinced that nothing is hanging up or broken in
there. The only wear I could see at all was a high mirror polish on the
tips of the PTO gears. The differential didn't show any wear beyond
break-in that I could detect.

The schematic shows that the hydrostatic circuit gets its fluid charge
from the two check valves he welded shut... duh! Why didn't he just
replace the o-rings that were leaking??????

The two valves are spendy, running over $350 for the two, but I think
it's a worthwhile expense. Since one of them is also a pressure releif
valve, I thought better of fabricating them... the charging pressure
really should be correct.

So, I've buttoned it back up, sans leaks. More when the valves arrive
via slow post.

LLoyd

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
I had a messy but fun time pulling the Tuff Torq tranny off that old
JD455.

I've been working on the assumption that the shade-tree guy who welded
the tow valves shut actually caused the "no reverse" problem it has.
Now, I'm pretty convinced.

There were a couple of case leaks, so that offered an opportunity to peek
inside with good reason. But when I got the case open, I was completely
amazed.

This thing has 3K hours of actual mowing on it. There wasn't enough
swarf inside the case to dirty one fingertip! If I didn't mind the taste
of ATF, I could've eaten out of it.

Are you sure it uses ATF? Most hydrostats use motor oil or Universal Tractor
Hydraulic Fluid (UTH). ATF is usually the worst thing for them.

-Carl

"Carl Byrns" fired this volley in
news:xkfDi.6608$2N2.3579@trndny03:

Are you sure it uses ATF? Most hydrostats use motor oil or Universal
Tractor Hydraulic Fluid (UTH). ATF is usually the worst thing for
them.

-Carl




Tuff Torq _specifies_ Type-F ATF. John Deere says, "NO! Buy our 'special
low-viscosity hydrostatic fluid' -- it's RED". G

LLoyd

On Tue, 04 Sep 2007 15:07:41 -0000, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

snip good description
The schematic shows that the hydrostatic circuit gets its fluid charge
from the two check valves he welded shut... duh! Why didn't he just
replace the o-rings that were leaking??????

The two valves are spendy, running over $350 for the two, but I think
it's a worthwhile expense. Since one of them is also a pressure releif
valve, I thought better of fabricating them... the charging pressure
really should be correct.
snip

Hi LLoyd,

Because the valves are spendy and he had a quick fix?

Many years ago when I was a teenager... I took a look at a
friends old Bridgestone motorcycle. It was just small one,
probably under 100cc. It didn't run and they (father and
him) took the cracked flywheel to someone to weld. They
could see it was lose on the tapered crankshaft and thought
they had found the problem. Still didn't work when they
bolted it back on. It was cracked in the same area as the
pulley Wes is working on fixing. I found it with a really
nice weld/bead run over the crack. Only problem with this is
that is the surface that the points rub on/use. Obvious to
me, even though I had never seen one quite like it before.
My friend could just see the crack and not the cam-shape on
the wheel, points that run on it...

Some people just shouldn't try to fix stuff

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

On Tue, 04 Sep 2007 16:02:37 GMT, "Carl Byrns"
wrote:


"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
.3.70...
I had a messy but fun time pulling the Tuff Torq tranny off that old
JD455.

I've been working on the assumption that the shade-tree guy who welded
the tow valves shut actually caused the "no reverse" problem it has.
Now, I'm pretty convinced.

There were a couple of case leaks, so that offered an opportunity to peek
inside with good reason. But when I got the case open, I was completely
amazed.

This thing has 3K hours of actual mowing on it. There wasn't enough
swarf inside the case to dirty one fingertip! If I didn't mind the taste
of ATF, I could've eaten out of it.

Are you sure it uses ATF? Most hydrostats use motor oil or Universal Tractor
Hydraulic Fluid (UTH). ATF is usually the worst thing for them.


That varies a lot. In fact all of the John Deere's I've seen specify
ATF (admittedly my experience is with much older machines). In my case
there is a mess up in the manuals somewhere. My factory service manual
calls for Type F where my factory owners manual calls for Type A. Both
manuals are for my year model and serial number as well. Well for my
oldest one anyway, I've actually got three of them with the last two
having the same transaxle despite a number of years difference and
different model numbers as well. I've never seen anything other than
Type A in any of them.

On Tue, 04 Sep 2007 15:07:41 -0000, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

I had a messy but fun time pulling the Tuff Torq tranny off that old
JD455.

I've been working on the assumption that the shade-tree guy who welded
the tow valves shut actually caused the "no reverse" problem it has.
Now, I'm pretty convinced.

There were a couple of case leaks, so that offered an opportunity to peek
inside with good reason. But when I got the case open, I was completely
amazed.

This thing has 3K hours of actual mowing on it. There wasn't enough
swarf inside the case to dirty one fingertip! If I didn't mind the taste
of ATF, I could've eaten out of it.

Great news.

Now I'm completely convinced that nothing is hanging up or broken in
there. The only wear I could see at all was a high mirror polish on the
tips of the PTO gears. The differential didn't show any wear beyond
break-in that I could detect.

The schematic shows that the hydrostatic circuit gets its fluid charge
from the two check valves he welded shut... duh! Why didn't he just
replace the o-rings that were leaking??????

I never cease to be amazed at some of the stupidity people do.

The two valves are spendy, running over $350 for the two, but I think
it's a worthwhile expense. Since one of them is also a pressure releif
valve, I thought better of fabricating them... the charging pressure
really should be correct.

Well worth the money for a mower of this quality.

So, I've buttoned it back up, sans leaks. More when the valves arrive
via slow post.

Sounds good.

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
"Carl Byrns" fired this volley in
news:xkfDi.6608$2N2.3579@trndny03:

Are you sure it uses ATF? Most hydrostats use motor oil or Universal
Tractor Hydraulic Fluid (UTH). ATF is usually the worst thing for
them.

-Carl




Tuff Torq _specifies_ Type-F ATF. John Deere says, "NO! Buy our 'special
low-viscosity hydrostatic fluid' -- it's RED". G

LLoyd

That is weird- both Sundstrand and Eaton specifically say not to use ATF.
And Type F has an abrasive component, IIRC (or was that Dexron?).
Can you even buy Type F anymore?

-Carl
--
The future isn't what it used to be.

Wayne Cook fired this volley in
:
My factory service manual
calls for Type F where my factory owners manual calls for Type A. Both
manuals are for my year model and serial number as well. Well for my
oldest one anyway, I've actually got three of them with the last two
having the same transaxle despite a number of years difference and
different model numbers as well. I've never seen anything other than
Type A in any of them.

Are yours in the same class as the 455? Do you know the tranny type off-
hand?

My Deere manual says "never use ATF, it causes clutch chatter". Tuff
Torq says they've never recommended anything else, and have never heard
of a clutch chatter problem on the K92 transaxle.

LLoyd

On Thu, 06 Sep 2007 11:32:38 -0000, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Wayne Cook fired this volley in
:
My factory service manual
calls for Type F where my factory owners manual calls for Type A. Both
manuals are for my year model and serial number as well. Well for my
oldest one anyway, I've actually got three of them with the last two
having the same transaxle despite a number of years difference and
different model numbers as well. I've never seen anything other than
Type A in any of them.

Are yours in the same class as the 455? Do you know the tranny type off-
hand?

Mine are much older and about one step down in size (back then they
where the largest they made). My newest one is a 350 (or something
like that in the 300 series) the older ones are from before Deere
revamped the numbering system and are 140's (but they're all the same
size). I'd have to look but I'm pretty sure they all use Sunstrand
hydrostats (I know the oldest one is). The oldest has a completely
different layout compared to the other two.

My Deere manual says "never use ATF, it causes clutch chatter". Tuff
Torq says they've never recommended anything else, and have never heard
of a clutch chatter problem on the K92 transaxle.

Saywhat? What clutch? I know I didn't study your break down very
hard but I sure don't remember a clutch in there. My oldest model
actually has a clutch on it but it's mounted on the flywheel of the
engine. It's dry and stops the input shaft to the hydrostat.

Wayne Cook fired this volley in
:

Saywhat? What clutch? I know I didn't study your break down very
hard but I sure don't remember a clutch in there. My oldest model
actually has a clutch on it but it's mounted on the flywheel of the
engine. It's dry and stops the input shaft to the hydrostat.

PTO clutch. The hydrostatic circuit is a "true" hydrostatic, using the
zero-displacement position of the pump for "neutral".

The PTO clutch is a pilot-operated, damped, single-acting, spring-return
cylinder that presses a composition disk against a metal pressure plate.

LLoyd

On Fri, 07 Sep 2007 11:28:17 -0000, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Wayne Cook fired this volley in
:

Saywhat? What clutch? I know I didn't study your break down very
hard but I sure don't remember a clutch in there. My oldest model
actually has a clutch on it but it's mounted on the flywheel of the
engine. It's dry and stops the input shaft to the hydrostat.

PTO clutch. The hydrostatic circuit is a "true" hydrostatic, using the
zero-displacement position of the pump for "neutral".

The PTO clutch is a pilot-operated, damped, single-acting, spring-return
cylinder that presses a composition disk against a metal pressure plate.


OK. That's possible. There's nothing remotely similar on any of
mine.