new mod.

[KentT]

Have you thought about fabricating mounting boxes for the new wheel motors to set in and welding them to the sides of the pt so that the wheel motors sit completly outside the tubs {assuming that the wheel motors fit inside a cutout in the sides of the model that you have. If you did it that way you could build the motor mounts first and set the motors in the new mounting box and see how it fits and then weld the boxes to the sides of the pt. It would probably make for a wider stance for the pt but that might be good for the ground that you are using it on for stability. I might not have a grasp of your situation and if that is the case disregard this post. Hope you get your pt to operating at an acceptable performance for your situation. Also have you had ererything checked out on your pt to make certain that you don't have a mechanicle problem first?

I've looked at several different combinations/possibilities. I thought about having some boxes fabricated, but I roughly estimated their cost tp be somewhere in the $250 - $300 range, to cut and bend the steel, then drill/cut the shaft and mounting holes. If I went that route, I'd also likely move to the White CE or Char-Lynn W series, "short & stubby" motors like Tazewell has done. But, they're also 1.25" tapered shafts, which would require new hubs also since mine are 1".

I haven't checked out the system to make certain everything is functioning correctly -- I talked to Terry last week about that, and he said the only things I can readily check on the tram pump is the pressure on the charge pump (about 100 PSI cold and 90 PSI hot). As far as the pump's output, he said there's no easy way to check it and suggested that I either remove the pump and send it to Tazewell or bring the whole PT to Tazewell. He said they can typically tear down, inspect and repair a tram pump in one day. He estimated the cost to be $900, worst case, to rebuild it if they had to replace the pistons. I certainly may have a scratched swash plate or something that in limiting the output pressure, but with only about 400 hours on the machine, I'm thinking/hoping not. That's another reason for me to try holding down the cost of the wheel motor upgrade -- just in case more work is still needed.

My challenge is that I'm trying to use the machine on slopes that are the upper limit of the PT-425's design capabilities, I think, and these old-style wheel motors are marginal, at best, in those circumstances. If I paid to rebuild the pump first, I'm afraid I'd still have a marginal-performing machine for where I'm trying to use it. I want it's slope-handling capability to be limited by the engine's oiling system, and not the weak wheel motors. That's one of the reasons I wanted an older PT with a Kohler engine instead of the Robin -- 25 vs 20 degree (as far as I can tell) restrictions based on the engine's oiling system.

The edge of the small brush pile(s) in the pictures below show the limit of slope-climbing capability with a load of brush in the grapple bucket when the oil is hot... I have several places that if I go down into them I must climb a fairly steep slope to get back out, and by the time I come back out from working, the oil is always hot and thinner. When cold, it does OK -- not great, but OK.

This larger view at this link gives a view of the overall work area that I'm using it on. The only flat spots are those I've created in the lower driveway...

http://www.loonlanding.info/images/mulch/mm_30_800.jpg

Here's a topo map of the lot, showing about 100 feet of elevation gain from the lakeshore to the back of the lot (less than 500 feet) where the picture linked just above was taken. The only slope I'm sure of is where the house and garage will go. We shot it with a transit and I have 11'2" of elevation gain in 80', meaning I'll have to cut down two more feet at the top of the building area (beginning at the next to last picture above and going down the hill from there), leaving a 9' walkout basement, and a back driveway that's even steeper than it is now. The gentlest slopes I'll then have are probably 15 degrees (just guessing) with most in the 20-25 degree range, and some steeper that I'll never be able to operate the PT on unless I'm going straight up and down the slopes.

http://www.loonlanding.info/topo1.jpg

So, my thinking is to address these old-syle wheel motors first -- which are known to be weak for these conditions, then go from there...

It sounds like I might be dissatisfied with the PT -- I'm not at all -- I'm overall quite pleased. I tried a little 4WD Kubota on these slopes and it fared much worse (often spinning rather than losing power), so I replaced it with the PT. If I had a new 425 with the larger wheel motors, I'd likely be "learning to live within its limitations" -- but with this older 425 with the small wheel motors, I'm trying to make it less limiting...

 

[MossRoad]

Don't forget that you will end up with this once in a while.

Here's a better look at the backside of the left front wheel motor.

 

[KentT]

Don't forget that you will end up with this once in a while.

Here's a better look at the backside of the left front wheel motor.

LOL... yes, I certainly have that to look forward to...

One of the first tasks I'll need to do in June on vacation is to "bush-hog" it since it hasn't been cut yet, after seeding it last spring with a mix of fescue and annual rye. There will likely be some mini-hoe work also, continuing to pull out the wild holly and other undergrowth. Then, I'll be hauling and spreading mulch from the slash-grinding operation up into the edge of the tree-line, where I'm trying to keep the undergrowth down. I cleared some of the undergrowth out of the woods above the lower driveway and spread a little mulch last year, but I've literally got weeks of work to do yet...

This mulch pile is 6' to 10' (or more) tall and about 100' long:

Meanwhile I got another quote back yesterday, on the larger 22.7ci Char-Lynn motors that I spec'd earlier (low-speed valving & high-pressure seals). I guess they can be built, though these might be the first ones Char-Lynn has made. That quote was $358 per motor with a 4 week "build" time. They'd be about 1" longer than stock (7.02") but would require the same cutting/grinding to get them in that Johari did -- they're the same diameter as the 18.2ci ones, just about 1/2" longer.

Though more expensive than the White WR series, that may be the way to go, since there would be less clearance issues with the front loader arm mounts and in the engine compartment. Plus, I'd then have all the torque that it's readily feasible to put in a PT-425 -- potentially 5,000 in lbs at 1500 PSI (intermittent only) from 4gpm flow on up, and well over 4300 in lbs at 1300 PSI at all flows. Torque should not then be an issue.

Meanwhile, I'm still waiting on my mechanic friend to check out my PT closely and tell me what he's willing to tackle...

ADDED: It certainly pays to shop around. I received two more quotes back on the same 22.7ci motor just now. One quote is $409.84 and the other is $419.84 -- in comparison to the $358.00 quote I received yesterday.

 

[MossRoad]

This mulch pile is 6' to 10' (or more) tall and about 100' long:

That pile should only take you a day or two depending how far you have to move it. This is just one area where the PT far outworks anything else in it's price and weight class.

As for shopping around, you got that right. While not on the price scale of your wheel motors, I was just talking to the wife about the chicken we roasted at home last weekend. I cooked it with loving care and we enjoyed a fine meal. Afterward, she informed me that the raw, whole chicken was over five bucks and we could have bought a whole chicken already cooked in the Deli for $4.59!!! There's something wrong with that!

I did not get a measurment from the back edge of the front wheel motors to the edges of the lift arm brackets. I could get that for you late tonight or maybe tomorrow night, if you need it. I have to work on the kids' school's printers tonight. Someone was kind enough to donate 10 network capable laser printers so I figured I'd be kind enough to install them.

 

[toy]

That pile should only take you a day or two depending how far you have to move it. This is just one area where the PT far outworks anything else in it's price and weight class.

As for shopping around, you got that right. While not on the price scale of your wheel motors, I was just talking to the wife about the chicken we roasted at home last weekend. I cooked it with loving care and we enjoyed a fine meal. Afterward, she informed me that the raw, whole chicken was over five bucks and we could have bought a whole chicken already cooked in the Deli for $4.59!!! There's something wrong with that!

I did not get a measurment from the back edge of the front wheel motors to the edges of the lift arm brackets. I could get that for you late tonight or maybe tomorrow night, if you need it. I have to work on the kids' school's printers tonight. Someone was kind enough to donate 10 network capable laser printers so I figured I'd be kind enough to install them.

For a minute I thought you was talking about not getting a measurment on the chicken. lol. To Kent have you made sure the throttle is opening up all the way on the engine. If it is not going full throttle that would cause some of the problems with the engine stalling and with it not having the torque you want and if you only needed to adjust the throttle linkage that would save you a bundle. If you just want to power up your machine with more power go for it bigger is better most of the time that is.

 

[ddonnell]

KentT,

Is it the built in check valve feature in some of these motors that provide "braking"?

 

[KentT]

KentT,

Is it the built in check valve feature in some of these motors that provide "braking"?

I'm not sure, but I think the braking is done by simply stopping the flow of fluid through the system -- essentially turning the wheel motors into pumps, with the pressure they generate pushing back against the hydro pump.

The larger PTs have an emergency/parking brake built in to the motor that requires hydraulic pressure to release it (similar to the air brakes on a semi). Should a line burst the spring-loaded brakes automatically come on.

I've seen that check valves are offered as options on some hydraulic motors, but I'm not sure what it does. Check valves are typically used to block fluid flow in one direction while allowing it to flow in the other direction. On wheel motors, they need to go in both directions...

Believe me -- I'm no hydraulics expert -- I've just learned a lot about hydraulics since I got the PT...

 

[KentT]

Just an update...

Having been contacted by an Eaton field rep who wanted to discuss my needs a couple of days ago, I finally broke down and ordered the Char-Lynn S-series 22.7ci motors today. I don't have an estimated ship date for this special order, but I was told it should be somewhere between 4-6 weeks. Eaton actually has to create a part number and make sure they can tool up for this configuration -- that's what the field rep was calling about. No one has ever ordered this size motors with the combination of low-speed valving, high-pressure seals and 1" tapered shafts...

As I mentioned earlier, it'll probably be the end of June before I can report back with the actual results, any way -- but I'm looking forward to trying twice the power (torque) at a bit more than 1/2 the speed...

Though more expensive than the White WR-series 19.8ci motors, the Char-Lynn motors appear to be easier to install because of potential interference with the front lift cylinder mounts. (They're an inch shorter.) And if I'm going to pay this much for the upgrade, I'm going to "go for the gusto" ...

If I find they're "too slow" I alway can speed it back up some by using taller tires, such as those meaty 26x12x12 lugs...

 

[KentT]

Just wanted to provide an update...

With my typical luck, 3 of the 4 new wheel motors were back-ordered by Char-Lynn and still not have shipped, so I didn't get a chance to get them installed and tested during my recent trip to TN...

I'll provide feedback when I finally get them installed...