Multiple hydraulic problems JD 4300 HST

[underwritten]

I NEED DESPERATE HELP..
I have a JD 4300.. I had the clutch replaced about 20 hours of run time ago.. Tractor seemed to be working strong.. Then it totally lost any torque at all.. It has decent power in reverse but hardly any in forward.. I have tried adjusting the clutch to no avail. Also, the steering is very inconsistent. You have to stop and give it a few seconds to get the steering to work.. It will work for 60 secs or so then quit again.. Could this be a hydraulic pump issue.. ANY SUGGESTIONS>>
BRAD

 

[dfkrug]

I have a JD 4300.. I had the clutch replaced about 20 hours of run time ago..

The 4300 came with two "gear" trannies (collar-shift and sync-shift),
in addition to a "sync-reverser", and a hydrostatic trans.

Which one do you have?

 

[dfkrug]

Sorry these pics are a little blurry.

The blow-up is a bit blurry, as you say. I suspect they are from the
steel splash plate that is below the 3-pt cylinder, and above the PTO
clutch/brake assembly. Can you see any marks on the pieces that are
NOT due to trauma? The splash plate is unmarked and made of plate
steel of about 1/16" thickness, as I recall.

When a clutch friction disc fails, it can shoot out of the basket and
hit this plate enough to push it into the spinning clutch/brake assembly.

 

[RoyJackson]

I NEED DESPERATE HELP..
I have a JD 4300.. I had the clutch replaced about 20 hours of run time ago.. Tractor seemed to be working strong.. Then it totally lost any torque at all.. It has decent power in reverse but hardly any in forward.. I have tried adjusting the clutch to no avail. Also, the steering is very inconsistent. You have to stop and give it a few seconds to get the steering to work.. It will work for 60 secs or so then quit again.. Could this be a hydraulic pump issue.. ANY SUGGESTIONS>>
BRAD

Did the tractor operate OK before the clutch replacement (other then the slippage of a bad clutch)?
dfkrug's question never did get a response, but I don't believe a sync-shift or collarshift would exhibit these symptoms (no reason to go into the gearbox).

With only 20 hours, you may still be in warranty from the repair. Either way, I'd contact the person or company that did the clutch job ASAP.

 

[RoyJackson]

The blow-up is a bit blurry, as you say. I suspect they are from the
steel splash plate that is below the 3-pt cylinder, and above the PTO
clutch/brake assembly. Can you see any marks on the pieces that are
NOT due to trauma? The splash plate is unmarked and made of plate
steel of about 1/16" thickness, as I recall.

Pics are blurry, but the metal looks too thin to be 1/16th. If it's "stiff" (meaning you can't easily flex it), I'd say a it's from the outer cage of a small ball or roller bearing. If it flexes fairly easily, it may have come from the metallic parts of a filter (you know how filters are sometimes cut off or destroyed when removing one that had been installed too tightly).
It's possible those pieces have been in the system since manufacture, but they do not appear to be chips or shavings from machining. Anyway, IIRC they are not magnetic.

 

[dfkrug]

Pics are blurry, but the metal looks too thin to be 1/16th. If it's "stiff" (meaning you can't easily flex it), I'd say a it's from the outer cage of a small ball or roller bearing. If it flexes fairly easily, it may have come from the metallic parts of a filter (you know how filters are sometimes cut off or destroyed when removing one that had been installed too tightly).

I sure can not tell how thick they are from the photos. Some ARE too big
to go thru hardlines and hoses. They do not have the spot welds that
you see on ball bearing cages and are too big for that anyway. There
are no roller bearings in the gearbox.....all are ballbearings.

If the OP got that much out of the suction filter hole, then there are more
pieces in the bottom of the gearbox for sure. He needs to take the PTO
hatch off and clean out the bottom of the gearbox. Then he will see if
the splash plate is still there (photo). I have had every bit of this apart,
and this is my best estimate for what the fragments are from.

 

[RoyJackson]

I sure can not tell how thick they are from the photos. Some ARE too big
to go thru hardlines and hoses. They do not have the spot welds that
you see on ball bearing cages and are too big for that anyway. There
are no roller bearings in the gearbox.....all are ballbearings.

If the OP got that much out of the suction filter hole, then there are more
pieces in the bottom of the gearbox for sure. He needs to take the PTO
hatch off and clean out the bottom of the gearbox. Then he will see if
the splash plate is still there (photo). I have had every bit of this apart,
and this is my best estimate for what the fragments are from.

Some bearing cages are machined so you might not see spotwelds.
No matter what any of us think it is, I sure agree the access plate to the bottom of the transmission has got to come off.

 

[dfkrug]

Some bearing cages are machined so you might not see spotwelds.

That may be, Roy, but we are talking about a specific tractor here. THIS
tractor (and all other JD units I have been into) use this style of bearing,
with very visible welds in the cage (photo). The parts of the cage that
hold the balls have a very discernable curve to them, too. I clearly
remember rebuilding a Datsun 5sp tranny many years ago that experienced
a failure in one of the ball cages. I don't think I have ever seen a
ballbearing cage that had invisible welds....but I am not saying they
don't exist.

I do want to correct one thing I said: there is one small roller bearing inside
the 4300 gearbox, and it has no welds on the roller cage. It is a small
bearing on the end of the main shaft and the cage is too small to be the
OP's failure.

 

[RoyJackson]

That may be, Roy, but we are talking about a specific tractor here. THIS
tractor (and all other JD units I have been into) use this style of bearing,
with very visible welds in the cage (photo). The parts of the cage that
hold the balls have a very discernable curve to them, too. I clearly
remember rebuilding a Datsun 5sp tranny many years ago that experienced
a failure in one of the ball cages. I don't think I have ever seen a
ballbearing cage that had invisible welds....but I am not saying they
don't exist.

I do want to correct one thing I said: there is one small roller bearing inside
the 4300 gearbox, and it has no welds on the roller cage. It is a small
bearing on the end of the main shaft and the cage is too small to be the
OP's failure.

I take it you're talking about those spotwelds on the ball retainers?
Cages I'm describing are machined or stamped and either steel or brass (used in bus transmissions and are pretty expensive). With those cages, the balls or rollers are retained by a cage that would be equivalent to the outside diameter. It appears the balls (in your picture) are retained by that spotwelded assembly and the race is just outside of that.
I've never had a tractor tranny apart, but I have had a few automotive transmission torn down. Can't say I've ever seen a spotwelded bearing...but there's always a first time!

I could definitely see how the ball retainer could disintegrate if just one of those spotwelds sheared. Due to the curvature of the retainer, I don't think that's what was in the earlier picture (most of the metal looked like it was flat at one time). That's an opinion, not a fact. If I had those metallic pieces in my hand...might have come to a different conclusion.
I'd also think there would be more then hydraulic problems if a bearing disintegrated. There would be a shaft binding or wobbling.

However, this is all conjecture. No matter what the metal came from, it's possible (or probable) there's more in the sump.

I do have one question, dfkrug...the bearing in your picture...was it stainless steel? The OP did write the pieces weren't attracted to a magnetic.

 

[dfkrug]

I do have one question, dfkrug...the bearing in your picture...was it stainless steel? The OP did write the pieces weren't attracted to a magnetic.

The OP said they WERE magnetic (#27). I am not aware of any of these
parts I mentioned being made of SS, but I don't check that unless there
is a reason to. Or I was fishing them out of the sump with a magnet. I
would not expect any stainless steel in there.

If the parts were non-magnetic, then they would most likely be from the
clutch pack or brake pack. The friction discs look metallic, but I suspect
there is no steel in them. The clutch plates are steel, but they are less
likely to fail vs. the friction discs (based on my tractor plus the experience
at the rental yard). Failed PTO clutches are a big problem with these
tractors.