Comparison PT 1460 traction

[J_J]

American Bulldog,

What is the model # of your pump?

and or

Maybe show a picture

 

[woodlandfarms]

So one thing I noticed BD was that you said WOT on the engine, and pedal to the metal on the treddle (foot pedal) and you can't get up the hills.

This would be correct, not a flaw but how hydraulics work in this cofiguration. The foot pedal works inversely of what you think it should. While it will get you going faster, it will reduce your oomph. backing off the treddle will get you up the hill. I am always mowing at 2/3rds power (2200RPM) and seldom get the treddle down. It is hard to do this when scooping. Generally my tires break free when scooping so I know when to back up.

I can see how an extra 2K would be way too much for the 65HP engine. With mower deck I slow down going up hills

There is a quirk on my machine as well that sounds the same. I can get some serious oomph in reverse, but it doesn't feel the same in forward. Have you ever picked your machine up off the ground (all four tires) and turned on the engine, release the brakes and see if your wheels spin. They should not. Mine do, in reverse. It isn't much but on the ground I can creep backwards if I am level. I have been too lazy / afraid to call PT and ask how to adjust, but there is an adjustment on the hydraulic control on the top of the tram pump.

 

[woodlandfarms]

One other thing, as far as I know you are the only owner of a 1460. Like the 1850 it is tough to compare to another model (your 1445 or 1430) I assume each machine has quirks that are unique to its design.

 

[woodlandfarms]

Jeez, should have read the post better. You said thicker oil. I don't agree. Some of us (the wealth ones which is not me) have gone to Synthetic as it appears to run cooler. I feel my engine runs cooler with synth, but I do not have it in my tram system. Have you ever put a thermometer on your tank to see how hot you are really running? I assume from your picture your maintenance is solid, that your keep your cooler clean, and that the fan on the top comes on and off.

Anyway, I don't think the change in density of your oil will improve your situation, but I make movies and have no real solid anything too back up my statements.

Oh, have you modded the outflow of your engine oil cooler? I did and I think ken did and that made a world of difference in engine temps. I raised the deflector on the output of the engine and it increases the air flow in my opinion.

 

[MossRoad]

I think by thicker oil, people are meaning higher viscosity numbers. For example, my PT was delivered with 10w40. If I start adding 5W50 that is thicker oil at operating temperature even though it is thinner at start up.

 

[cqaigy2]

As far as i can make out some of the articles on oils that are made today, the current oils lubricate much better then the old ones. So oils that have a higher viscosity don't lubricate better then lower viscosity oils, and higher viscosity oils heat up more and faster when compared to lower viscosity oils. That's specifically when used in engines. Donno what would be the off shoot of that in hydraulic systems.

 

[ponytug]

True: modern oils have better defined lubricating properties.

The issue for us is that our oil is used in a hydraulic system, where it needs to lubricate the pumps and piston seals, but where a low viscosity oil will leak past a seal faster and in larger volumes than a more viscous oil. Higher leakage implies power loss, which implies more pump motion, which implies more heating...

For a given weight oil, lower weight oils are less viscous and therefore generate less heat by moving. However, less viscous oils will generate greater power losses and greater blow by heating than higher viscosity oils in a hydraulic system. (In an engine too, but tolerances are much tighter in today's engines.)

Added to all of this is that the wheel motors that we use are specified for a given weight oil. In the manuals that I have read, it tends to be a straight 30 weight oil. I have no idea how much of an approximation a 10W40 oil is over the range of conditions that we use it our tractors in.

As always, YMMV. I never have to start my PT in -20F conditions. Mine just needs to work when hot on steep slopes.

All the best,

Peter

As far as i can make out some of the articles on oils that are made today, the current oils lubricate much better then the old ones. So oils that have a higher viscosity don't lubricate better then lower viscosity oils, and higher viscosity oils heat up more and faster when compared to lower viscosity oils. That's specifically when used in engines. Donno what would be the off shoot of that in hydraulic systems.

 

[American Bulldog]

True: modern oils have better defined lubricating properties.

The issue for us is that our oil is used in a hydraulic system, where it needs to lubricate the pumps and piston seals, but where a low viscosity oil will leak past a seal faster and in larger volumes than a more viscous oil. Higher leakage implies power loss, which implies more pump motion, which implies more heating...

For a given weight oil, lower weight oils are less viscous and therefore generate less heat by moving. However, less viscous oils will generate greater power losses and greater blow by heating than higher viscosity oils in a hydraulic system. (In an engine too, but tolerances are much tighter in today's engines.)

Added to all of this is that the wheel motors that we use are specified for a given weight oil. In the manuals that I have read, it tends to be a straight 30 weight oil. I have no idea how much of an approximation a 10W40 oil is over the range of conditions that we use it our tractors in.

As always, YMMV. I never have to start my PT in -20F conditions. Mine just needs to work when hot on steep slopes.

All the best,

Peter

10W40 is actually more viscous than SAE30.

10W40 @40degC, cSt is roughly 95
SAE30 @40degC, cSt is roughly 86

10W40 @100degC, cSt is roughly 14
SAE30 @100degC, cSt is roughly 11

I think the heavier oils will work fine when up to temp, it is the viscosity at startup that may cause a problem. My PT behaves pretty strange when the oil temp is below 40 degF.

 

[American Bulldog]

Jeez, should have read the post better. You said thicker oil. I don't agree. Some of us (the wealth ones which is not me) have gone to Synthetic as it appears to run cooler. I feel my engine runs cooler with synth, but I do not have it in my tram system. Have you ever put a thermometer on your tank to see how hot you are really running? I assume from your picture your maintenance is solid, that your keep your cooler clean, and that the fan on the top comes on and off.

Anyway, I don't think the change in density of your oil will improve your situation, but I make movies and have no real solid anything too back up my statements.

Oh, have you modded the outflow of your engine oil cooler? I did and I think ken did and that made a world of difference in engine temps. I raised the deflector on the output of the engine and it increases the air flow in my opinion.

I don't have any trouble with the engine overheating, but that is because I don't mow with it. All other applications I do, the power is much more intermittant. I removed the deflector BTW.

 

[American Bulldog]

So one thing I noticed BD was that you said WOT on the engine, and pedal to the metal on the treddle (foot pedal) and you can't get up the hills.

This would be correct, not a flaw but how hydraulics work in this cofiguration. The foot pedal works inversely of what you think it should. While it will get you going faster, it will reduce your oomph. backing off the treddle will get you up the hill. I am always mowing at 2/3rds power (2200RPM) and seldom get the treddle down. It is hard to do this when scooping. Generally my tires break free when scooping so I know when to back up.

I can see how an extra 2K would be way too much for the 65HP engine. With mower deck I slow down going up hills

There is a quirk on my machine as well that sounds the same. I can get some serious oomph in reverse, but it doesn't feel the same in forward. Have you ever picked your machine up off the ground (all four tires) and turned on the engine, release the brakes and see if your wheels spin. They should not. Mine do, in reverse. It isn't much but on the ground I can creep backwards if I am level. I have been too lazy / afraid to call PT and ask how to adjust, but there is an adjustment on the hydraulic control on the top of the tram pump.

I don't believe that the treadle works the way you say. I am assuming "oomph" is torque, or pressure to the wheel motors. The treadle controls a swashplate in the pump that directs the flow of the fluid. The maximum pressure is fixed, by some sort of adjustment on the pump.

Anyways, I have tried everything to get up the hills. Light treadle, heavy treadle, etc. Mine works much better in reverse, as your's does. I can stall the motor going uphill in reverse, if I mash the treadle down.