L3430HST Won't go forward but goes backwards fine...

[FarmerCraig]

I'm new to this folks so here we go:
Bought 3430HST from a older lady whose husband died like 3-4 yrs ago, 350 hours, shed kept but never moved since he died until it was "serviced" by a dealer (no record), no wear except the loader looks like it's scooped some gravel. I'm told it pulled a finish mower and their place was basically flat ground.

Brought it home and used it a bit moving dirt, no issue, let it set a month or so and went to scoop some gravel and it made a funny grinding noise a couple of times, so I quit that. let it set a couple more weeks and then it barely creeped forward but would still go backwards. Now it won't go forward at all but will go backwards full speed. The PTO will turn the mower.
I read the threads about the clutch failing but that always seem to involve no movement at all.
I noticed what seems be hydraulic fluid accumulated on the clutch housing plug, didn't get that pulled yet.
Is it possible I have a transmission from main seal failure that has soaked the clutch in hydraulic fluid?
Is it possible the hydraulic filer needs changed?
Or could there be biologics (slime) in the hydraulic fluid? I've seen this before on hydraulic equipment.
all thoughts appreciated...
thanks
C

 

[lugbolt]

leak is probably 4wd front propeller shaft seal. Known issue. There's a bulletin that address it, if out of warranty obviously they're not gonna pay for it but the bulletin addresses why it happens and what to do to fix it. Tractor has to be split to repair.

check the hst linkages.

 

[Justasquid]

Does it make any noise when trying to go forward? Or is there nothing at all?

I believe the forward and reverse use different relief valves. If that’s the case, you may just have a sticky relief valve on the forward side.

Also check the fluid level if you haven’t already. May not be a bad idea to drop the filter just to take a look at the fluid.

Are the filters white or gray? If they are gray, I would change them as this more than likely means they are the original filters.

 

[FarmerCraig]

Does it make any noise when trying to go forward? Or is there nothing at all?

I believe the forward and reverse use different relief valves. If that’s the case, you may just have a sticky relief valve on the forward side.

Also check the fluid level if you haven’t already. May not be a bad idea to drop the filter just to take a look at the fluid.

Are the filters white or gray? If they are gray, I would change them as this more than likely means they are the original filters.

Thanks for the feedback from both of you:
I don't hear fluid movement trying to go forward the way I do going backwards, call it hydraulic whine. If I depress forward very slightly it will "nudge", like it wants to go forward, but just barely.
Fluid level is normal, fluid is clear, not milky.
Filter is black, after market, gonna swap the filter and look at the fluid.
Is the relief part of the valve assembly, can it be adjusted or fiddle with a bit?
Obviously I would like to try this before I split the machine, which I'm not afraid to do.
Any idea where to get a reasonably priced shop manual?
Also pulling the flywheel case plug to see how much fluid might be in there..
C

 

[wgator]

If free is a reasonable price for the WSM, got to the following link: BY CLICKING HERE. You can view it online and also download it free from there.

 

[FarmerCraig]

If free is a reasonable price for the WSM, got to the following link: BY CLICKING HERE. You can view it online and also download it free from there.

COOL..
Thanks!!
c

 

[FarmerCraig]

Thanks for the feedback from both of you:
I don't hear fluid movement trying to go forward the way I do going backwards, call it hydraulic whine. If I depress forward very slightly it will "nudge", like it wants to go forward, but just barely.
Fluid level is normal, fluid is clear, not milky.
Filter is black, after market, gonna swap the filter and look at the fluid.
Is the relief part of the valve assembly, can it be adjusted or fiddle with a bit?
Obviously I would like to try this before I split the machine, which I'm not afraid to do.
Any idea where to get a reasonably priced shop manual?
Also pulling the flywheel case plug to see how much fluid might be in there..
C

I found the relief valve in the manual and on the tractor (thanks again wgator).
Is it possible some debris is holding the relief open?
Any trick to pulling this? the manual shows how to est it but not how to adjust it, if it is adjustable....
c

 

[ruger1980]

There should be a relief for forward and one for reverse. You could try swapping them and se if anything changes. Without have the manual myself to review it is hard to say if there is anything else in the circuit to look at.

 

[FarmerCraig]

changed filters, removed and re-inserted relief, now it goes forward but grinding noise. gonna rebuild the hydrostat I guess