PT422 on hilly terrain

[JamesR]

Hello:

I went to Tazewell today to get a first hand look at the Power Trac machines. The sales and maintenance folks at Power Trac were very courteous, patient, low (no) pressure, and answered all our questions. Overall, I was very impressed with their facilities and friendliness of their employees.

Incidentally, with a visit to the facility, Power Trac is offering a 5% discount on cash/check purchases until March 15. The regular 2% discount for up to 6 months after the visit still applies, but the 5% discount expires on the 15th. Scott said the discount was only started yesterday.

With that said, I was wondering how folks felt about the PT422's ability to mow on slopes around the 20% limit. Does it seem to easily handle the slopes with a 48" mower deck running? Any problems associated with mowing on slopes unique to the PT?

I'm sure this topic has been discussed at some point in this forum, but any feedback would be appreciated.

Thanks,
James

 

[MuncyBob]

I will mow the steeper slopes that I have while the fluid is still cool...seems I get better traction/mower power then. If I have steep slopes to finish after the fluids have become hot I either cut downhill when not able to go uphill or traverse the slope or I will back up a slope..I think the rear engine weight givesyou some better traction that way. If you try to cut up a steep slope with the fluids hot you will probably not make it all the way up before it bogs down..mower slows to almost a stop...then you need to kill the PTO and go up the slope. At first I was unhappy with this situation but now that I have my cutting "routine" down(mow 3 acres in season) it doesn't bother me at all and is a trade off for all the other things I can do with it. Hope this helps.

 

[BobRip]

For those kind of slopes you should definately go with the 425. It has 50% more wheel motor torque and the 3 extra horse power to get you up the slope.
I have a 25% slope (PT422) and I have to get a running start to mow up it, and then I don't make it to the top. The slope is only about 10 feet long.
Go with the 425.
Bob Rip

 

[SnowRidge]

A 20% slope isn't very steep at all. It is only around 10 degrees. Any PT should be able to handle that without any problems. Even if it was a 20 degree slope, the PT-422 should handle it. On the steeper slopes, the operator may have to back off the forward speed some so that enough power is available to the mower PTO, but that is normal with almost all tractors.

 

[SnowRidge]

Bob, what happens if you try to creep up that slope while the mower is running? I'm talking about just a tiny bit of forward pedal. I'm really curious about this hill problem you and Farmall140 are experiencing.

 

[JamesR]

SnowRidge:

I did post the slope wrong. It is 20 degrees, not 20%. There are some small stretches that are around 23 degrees, but not that much.

I did see where you thought the PT422 should handle the 20 degree slope.

Thanks for the info.

James

 

[SnowRidge]

Since I have a PT-425, not a 422, I'm not the most qualified to speak on the latter, but I'm having a hard time understanding why some folks are having problems on slopes. On my steep slopes, and I have a lot of them to mow these days, I just back off the right pedal until the mower stops bogging. I do the same thing on my gear tractor by shifting down to a lower range. (The pedals on the PTs are really infinite transmission range controls. All the way down is high gear, while just barely down is the lowest range.)

The older PT-425s did not have the high torque wheel motors of today's models, but I don't recall anyone having major problems with hills. I don't think the additional 3 HP would make that much difference.

 

[MuncyBob]

Most hills in the area that I cut grass are not a problem and I do have to let off the treadle to creep up all the way....I was thinking of STEEP hills when I mentioned some problem getting up.....I'm not sure what the grade is of the few really steep hills that I have but I would guess approaching 30-35 degrees?? /forums/images/graemlins/confused.gif

 

[Bob999]

<font color="red"> .I was thinking of STEEP hills when I mentioned some problem getting up.....I'm not sure what the grade is of the few really steep hills that I have but I would guess approaching 30-35 degrees?? </font>

STEEP has different meanings to different people.

I have an 1845 with dual wheels so stability on slopes up to 40 degrees is supposed to be satisactory according to PT specs. However my experience is that I run out of traction long before reaching 40 degrees. A slope of 25 degrees can be difficult unless conditions are dry. At 30 degrees I find that even with dry conditions that side slipping is a problem when mowing cross slope and a spinning wheel is a problem if working up slope.

 

[BobRip]

My mistake as well. My slope is 25 degrees.
Bob Rip

 

[BobRip]

If I try to creep, it just stalls. The wheel motors don't spin. My best torque is with the petal about 1/3 to 1/2 down. I have tried lots of things and this is the best option. This hill is not very big, so it is not much of a problem. Oh, I can also steer back and forth and this helps. I can work my way up slowly with left and right steer while applying the pedal.
Bob Rip

 

[RegL]

</font><font color="blue" class="small">( If I try to creep, it just stalls. The wheel motors don't spin. My best torque is with the petal about 1/3 to 1/2 down. I have tried lots of things and this is the best option. This hill is not very big, so it is not much of a problem. Oh, I can also steer back and forth and this helps. I can work my way up slowly with left and right steer while applying the pedal.
Bob Rip )</font>


That's my experience also. I think the transmission anolagy and what we are calling torque is not quite right. I'm not an expert, but I bet if you took a hydraulic motor(ie. wheel motor), the more volume and pressure you applied to it's input the more torque there would be at the output. Trouble is, when that motor is under heavy load(steep hill and good traction) it takes a lot of HP on the other end to keep all four motors digging. so like Bob says, it's a balancing act. Enough treadle to keep the wheel motors from stalling and not so much to make the engine stall.
Reg

 

[ernemats]

I also have a 422 with the 48" mower , about 6 years old and 850 hours on it. I mow some rather steep areas up to 25 degree slope, I usually mow cross slope. Mowing up hill with the mower running is a problem especially if the hydraulic fluid is hot, so I will mow down hill or cross slope most of the time. Mowing cross slope at anything over 20 degrees feels like maybe this is too steep to be doing this but I have never had any problems, and sometimes the tractor will sort of slide sideways a little, not much. I will take the power trac a lot of places I would never go with a normal tractor.

 

[BobRip]

There is also leakage (bypass, blowby, whatever you want to call it) around the motor and backwards through the pump. When the fluid is hot this leakage increases and torque decreases. If there were no leakage it would work much better at stall conditions. I use synthetic oil (Mobil 1 20W50) and it has been a big help. No system is perfect of course.

A bigger gasoline engine, bigger wheel motors and a bigger pump to drive the motors helps. The 425 has all of this. However, I have only one short hill where this is a problem. The other area that I get stuck in is a swamp and and no wheeled vehicle should go there.
Bob Rip

 

[SnowRidge]

<font color="blue"> A bigger gasoline engine, bigger wheel motors <font color="red"> and a bigger pump <font color="blue">to drive the motors helps. The 425 has all of this. <font color="black">

I didn't realize the tram pumps were different. I thought the PT-422 and PT-425 used the same pumps. If the pumps are different, it sure could explain a lot. I had a number of talks with PT about the differences between the two machines, and they never mentioned any pump differences.

I had a hard time understanding the large price difference between the two. Maybe the pump is a big part of it.

 

[BobRip]

I don't know about the bigger pump adding much cost, but it sure adds value. Actually without the bigger pump I think you would still get the torque, but your top speed would drop by 1/3. Someone has done that on TBN.
I would surely pay the difference between the 422 and 425 if I were buying a new machine. But of course a lot of this depends on your use. There are people here who love the 180, and compared to a riding mower, I can see why.
I continue to like the 422. The Mobil 1 is a factor, but more importantly is operating experience and techniques from this site. Intially I was getting stuck once a week. The wiggle walk on hills and big ruts solved a lot of that and experience helped too. Whenever you think the machine is not doing what it should, ask questions or do searches and there will probably be an answer.

Take care and buy a 425.

Bob Rip