425 again…movement problems…

[MossRoad]

Depending on the control system you have, they all can go out of alignment.

As @m5040 mentioned a certain amount of whining at low oil temperatures is to be expected to happen due to higher oil viscosity, but try to minimize it by letting the oil warm up. I believe that @MossRoad starts his and lets it run for a while (15 min?) while he does some hand shoveling. If your pump is not in trouble, the whining sound is the oil cavitation as it is being pump and the cavitation is very hard on, and damaging to, surfaces.

All the best,

Peter

Yes, that's what I do. About 1/3 throttle for 10-15 minutes while I hand shovel the steps and narrow walks where the PT won't fit.

I also run it at full throttle almost all the time, always. Have been doing that for 20+ years. Supplies better pedal response both starting and braking, as well as better air movement around the engine for cooling, or so I'm told.

 

[MossRoad]

Thanks again. I started reading about cavitation. One site mentioned this, concerning viscosity and cheap to expensive fluids:
“Therefore, most hydraulic systems should not be started up with the oil any colder than 40°F and should not be put under load until the oil is at least 70°F.”
Wow! The article was dealing with factory-type equipment and systems but I believe some of it extends to our equipment…

I've started mine below 0F many times. All I did was use a battery booster and a quick shot of starting fluid.

I've been running the factory hydro oil for 20 years. Every 50 hours when I change the filter, I add quart of Mobil 1. I'm about to do a total hydro oil change this spring. Figure it's about time.

 

[MossRoad]

The reason the filter is on suction side on utility is that the return oil is typically from 3 point hitch valve which dumps straight into the transaxle. On my 2400H their is a suction filter for both implement and charge pump and also a spin-on filter for the pressure inlet of the charge going into the HST.

The suction filter or screen is there to remove contaminants generated by the turning gears in transaxle, particles from PTO clutch, wet brakes, etc.

I agree that suction filter is not ideal but sized properly they do work.

If 50 hour change is required I would suspect a design problem with either a component generating a lot of debris or a very undersized filter since as filters remove contaminants the pressure drop across them increases.

The filter on my PT425 only filters make-up oil for the charge pump on the drive circuit. That's it. I recall it being only a few GPM. It does not filter any of the oil that goes through any of the PTO pumps. That's just a few continuous slop loops recirculating all the time unfiltered.

 

[Modrob]

Earlier this evening I had a few minutes…I cranked it up and let it run a while at a lower throttle. About 20 min later I throttled it up and looked in the tank. No bubbles, but at the higher throttle I did see some gentle “rolling over” of the oil. Kinda like a car radiator circulating. While I had the brake set, I gently pushed against the pedals. Right/forward tried to move and no noise. But left/reverse, just a very little force and it would start to move but the noise was there. Sounded like right at the pump. Tomorrow I’ll have my phone with me and possibly get a recording of it.

 

[ponytug]

Circulating oil waves are normal. The PTO pump runs, but dumps into the tank (no clutch) so that is a big flow.

I think that no whine attempting to go forward is a good sign. I'm out of my depth trying to interpret a whine just in reverse. Talk to Terry?

All the best,

Peter

 

[Modrob]

Circulating oil waves are normal. The PTO pump runs, but dumps into the tank (no clutch) so that is a big flow.

I think that no whine attempting to go forward is a good sign. I'm out of my depth trying to interpret a whine just in reverse. Talk to Terry?

All the best,

Peter

I’ll give them a call in the next day or two. Many thanks!

 

[m5040]

My tractor whines when against an immovable object (park brake, dirt pile etc).

 

[ponytug]

Circulating oil waves are normal. The PTO pump runs, but dumps into the tank (no clutch) so that is a big flow.

I think that no whine attempting to go forward is a good sign. I'm out of my depth trying to interpret a whine just in reverse. Talk to Terry?

All the best,

Peter

@Modrob I did notice tonight that my PT does whine a bit in reverse compared to forward motion. I don't know about yours.

As @m5040 wrote, it will whine if it is pushing against an immovable object.

All the best,

Peter

 

[Modrob]

@Modrob I did notice tonight that my PT does whine a bit in reverse compared to forward motion. I don't know about yours.

As @m5040 wrote, it will whine if it is pushing against an immovable object.

All the best,

Peter

Mine is LOUD, And that’s with very little load on it—like backing uphill…

 

[ponytug]

Mine is LOUD, And that’s with very little load on it—like backing uphill…

Ok.

Talk to Terry would still be my advice. He probably knows about the particular pump in your tractor and will be able to comment based on extensive experience.

All the best,

Peter

 

[m5040]

Yes Terry will be your best bet.

If you look on line to explain how a variable displacement pump works, it may give you some insight when discussing it. Wild guess on my part is that one of the pistons is not in sequence causing the weak movement and noise and you will need to send your pump in for rebuild.

 

[oldnslo]

Can you install a pressure gauge in the charge circuit for the hydrostatic pump(s)? Watch the charge pressure at standstill, then trying to drive forward & reverse. It should not change significantly under any of those conditions. I do not know what the charge pressure should be though.

 

[Modrob]

Can you install a pressure gauge in the charge circuit for the hydrostatic pump(s)? Watch the charge pressure at standstill, then trying to drive forward & reverse. It should not change significantly under any of those conditions. I do not know what the charge pressure should be though.

Hmmm interesting idea…I’ll have to study on how to do that.

 

[Modrob]

Finally another update…(too much cold, snow, rain, more snow…)
I’ll attach two videos to detail a little better. (I’ve forgotten—can I add videos? Can’t seem to figure it out)

 

[MossRoad]

Finally another update…(too much cold, snow, rain, more snow…)
I’ll attach two videos to detail a little better. (I’ve forgotten—can I add videos? Can’t seem to figure it out)

I've posted videos to YouTube then linked to them here. Works well.

 

[redman135]

Linked to wrong video. It is fireworks.

 

[Modrob]

Finally another update…(too much cold, snow, rain, more snow…)
I’ll attach two videos to detail a little better. (I’ve forgotten—can I add videos? Can’t seem to figure it out)

I've posted videos to YouTube then linked to them here. Works well.

Thanks for letting me know how…I couldn’t remember if I ever had posted one before—my memory has just too much crap going on and I can’t keep up with where, when, what, etc. I’ve done

 

[Modrob]

 

[Modrob]

 

[Modrob]

And again, pedaling forward there’s hardly any noise like this…and it moves ahead fine. Backwards and it’ll stall at slightest incline.(I haven’t had the time to make the call to Terry and crew)