New Wheel Motors - PT-425 (2002 Vintage)

   / New Wheel Motors - PT-425 (2002 Vintage) #1  

ahartman

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Sep 25, 2008
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I know there are a number of posts about this same topic, but wanted to see if anyone had some up to date info. My wheel motors have been switched out once a few years ago and now I have another one leaking. Before I do a seal replacement, I was wondering if anyone had recommendations for new motors which would give me a little more torque. I'm on pretty hilly land and any little bit of extra umpf I can get while mowing would be a help.

My PT-425 is from 2002. Any ideas on shaft and port sizes, displacement, etc... as well as places to purchase would be more than appreciated.
 
   / New Wheel Motors - PT-425 (2002 Vintage) #2  
You gain torque by cu in displacement, or increasing pressure.

All the wheel motors have to be the same or they will try and run at different rpm with a give GPM flow.

If you have the funds, just go with larger cu in wheel motors and you will gain torque, and the machines high end will be slower.

Surplus Center

Example:

20 cu in @ 3000 psi = 9,554 in lbs torque

25--------------------= 11,943 in lbs torque
 
   / New Wheel Motors - PT-425 (2002 Vintage) #3  
Just a heads up... if you go to larger displacement wheel motors, you may have to go to larger wheel motor mounting boxes.

KentT was going to do that, getting the larger boxes from Power Trac. Don't know if he proceeded with that project.
 
   / New Wheel Motors - PT-425 (2002 Vintage) #4  
Yes, I'm running the large wheel motors from Surplus Center with 1430 wheel motor boxes. I just haven't followed up with the promised update.

It's a Billy Goat, and will go anywhere it will get traction. I'm running 26x12x12 ag lug tires, loaded with windshield washer fluid, and it's working well. It is SLOW however, going only about 1/2 the speed it did originally. But, that's plenty fast enough for these steep hillsides. I've been too busy using it, to provide reports about it... :)

To put it into perspective, some before and after pics, of what I mowed with the brush hog and then raked the debris off with the landscape rake. View of the overgrown field below the house, from the yard - before.
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Alternate view, from the dining room deck:

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What it looks like now (actually last fall), from the yard. Most of that brush pile actually came from the yard, where I cleared out sprouts/saplings and low branches off the shade trees.


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I've "bush-hogged" about 4 acres or so with the Power Trac cutting hardwood brush up to about 1.5" and pines over 2"... then raked up the debris with the landscape rake.

I also pulled out a section of fence a few hundred yards long, that separated the yard from the field. It was overgrown with honeysuckle vines, and a cedar tree had blown down across it. Removing it made it much easier (and safer) to go up and down those slopes.

View from the back yard, looking down into the hollow, before...

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Similar view now. There's two piles of old tree trunks and stumps that run vertically up the hillside, where the field was initially cleared with a bulldozer, I'm guessing. I can't mow in there, and am contemplating just leaving them alone.
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The driveway/parking area, before, as you approach the house, initially:
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And now. I've spread 5 dump truck loads of fill dirt, levelling a spot (with retaining walls) to put a carport, and a better area to turn around.

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I've transplanted ornamental grass and yucca plants as visual borders and "guard rails" around the parking areas on both sides. Now I just need to get another load of gravel delivered and spread.

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Note the overgrown flower bed below the deck a couple pictures above. Here's what it looks like now, with the grasses and yucca moved out, and reseeded in grass.


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A couple of "superflous" decks on the lower level, where the previous owners had a small above-ground pool. There were simply too many decks/porches to try to keep maintained, and I won't be having a pool...

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Those two lower levels have now been removed, leaving the large 20x30 deck above. Here it is prior to final seed prep last fall:

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As you can see, I've been giving it a workout. My only caution with those large wheel motors -- it actually generates more wheel motor torque than the design spec for the PT-425. I bent the QA plate on the lift arms - TWICE -- until I finally learned that I need to use common sense, and not test the the limits of what it will pull or push...
 
   / New Wheel Motors - PT-425 (2002 Vintage) #5  
The place looks beautiful. Your hard work surely paid off!

There are plenty of times I wished I could go faster but it is not super important. More torque would be nice for ground contact equipment but there is no way I could increase it enough to make a difference. The one thing these tractors are not good for is plowing fields etc.

Ken
 
   / New Wheel Motors - PT-425 (2002 Vintage) #7  
Nice! Thanks for the update and picks. :thumbsup:
 
   / New Wheel Motors - PT-425 (2002 Vintage) #8  
Thanks, guys. Sorry that I hadn't provided an update earlier. One final bit of advice - I'd earlier tried to update the wheel motors with Char-Lynn S series motors with a 1" tapered shaft. While they certainly generated more torque, the 1" taper on the Char-Lynn shafts did NOT match the 1" taper on the Power Trac wheel hubs. I had continuing problems trying to keep the hubs tight on the motors, eventually wallowing out the soft metal of the hubs. To anyone thinking of upgrading, I'd suggest that you go ahead and bite the bullet for the additional expense to buy (or build) wheel motor boxes and go to the 1.5" tapered shafts and wheel hubs. The motors I bought from Surplus Center already had wheel hubs on them, with brake drums for 600mm drum brakes. I'm still searching for a set of backing plates and parts to make cable-operated parking brakes for this thing. Supposedly some golf carts used 6.25" cable operated brakes, but I haven't found a used set yet -- that's still on my To Do list...
 
   / New Wheel Motors - PT-425 (2002 Vintage) #9  
KentT ,

What size wheel motor in cu in did you have and what is the cu in of the new hyd wheel motors?

Was the 26 x 12 x 12 tires the original tire size.
 
   / New Wheel Motors - PT-425 (2002 Vintage) #10  
JJ,

I went with the 28.3ci White wheel motors: https://www.surpluscenter.com/item.asp?item=9-8092&catname=

Note that these require an adapter to adapt the British ports to standard SAE or NPT lines. They're the same motors that Woodland Farms used for one of his implements, unless I'm mistaken...

The original wheel motors on my PT-425 were 12.5ci White RS motors. I had upgraded them earlier to Char-Lynn S series 22.7ci motors. That reduced to speed of the PT to slightly more than 1/2 what it was originally, while almost doubling the torque. That size would have been large enough for my needs, but I couldn't get a permanent fix for the different taper on the Char-Lynn motors. After about 300 hours, I couldn't keep the hubs tight on the shaft, especially on the front...

The original tires were 23x10.50x12. I went to the 26x12x12 to help offset the change in RPM with the even larger 28.3ci wheel motors, and I needed new tires any way. The PT is just a bit slower now than it was when running the Char-Lynn 22.7 ci motors, but I get a bit over an inch more ground clearance, wider stance for stability, and even more wheel motor torque. The Char-Lynn S series, like the original White RS series, are not truly designed to be wheel motors -- they're more a general purpose hydraulic motor. The larger White RE motors from Surplus Center are designed specifically as wheel motors -- they're physically huge compared to the original RS series or the Char Lynn S series.

With the 1430 wheel motor boxes, and the brake hubs mounted on the White RE motors, the stance is slightly wider than the PT was with the wheels reversed, using the stock wheel motor boxes. I don't need to reverse the wheels with these RE wheel motors, but even if I did, there would no concerns about side loads. These are big, heavy-duty wheel motors...

Please note that these inexpensive White RE wheel motors do NOT have case drains, however... but my PT 425 didn't have them originally either so that actually simplified the upgrade. Some larger PTs have case drains, and this wheel motor would not be a good option for them...
 
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