The Stovebolt Site Forums The Parking Lot Big Bolts Looking for some hoist info

I have a pair of St. Paul Dumpit brand hoists. These are the "all in one" style with PTO pump, valving, and cylinder/reservoir in one unit mounted to a subframe.

I want to do a drivetrain change to a V8 and possible TH350 or TH400 setup yet keep the tilt bed.

I can't find much info on these hoists at all. I'm guessing by the size of the cylinder they are a lower pressure setup. I had thoughts of adapting a newer stand alone electric pump to the cylinder but I'm concerned the 3000psi they put out may not play well with the packing on the piston or worse yet blow the whole head off the cylinder. I have no idea what setting I would need for a relief valve to avoid sending too much PSI to the cylinder.

Other thoughts floating around are possibly an electric motor running the built in pump itself. This of course poses the problem of finding a motor that would run long enough to fully raise the bed without overheating. No idea of what HP or RPM requirement these things need either.

If I'm stuck with PTO so be it, I can find a 420 or 465 and maybe even a NV4500 for the OD. I would prefer auto as I have all the needed parts for that setup but I'll work with what I can. I do know I could run a t-case for the PTO it would provide but this option is below going with a manual in my list of preferences.

Any spec/thoughts/info you guys with more experience with these setups than I have would be great. I've used twin post single stage and telescoping setups before and I semi-proficient with hydraulics in general but have never built a system or added a PTO to anything.

Thanks all,

Chris

Just a reminder...the PTO Driven Gear needs to match the transmission/t-case unit you end up using...you can't just swap the PTO's from any old transmission to the next one, the gears won't mesh.

Also, see if there's a truck body company in your area and ask if they have suggestions...

Mike B

PTO's are transmission specific, so forget about engine.

Ed

Mike: I've done a bit of research and found that the 420 and 465 use the same PTO according to Chelsea anyway. The NV45 is a different beast and I never really looked for one for a 205 as I don't think I'd go that way at all. Auto isn't that important to me. I'll check with a local hydraulic shop we have...see if maybe they have some experience with these things. No truck body company around here per se.

Ed: That is kind of why I just put V8 as far as engine went.

More what I'm looking for is what sort of pressure and GPM these old hoists worked on. If I can find that info I can maybe find an electric hydraulic pump/motor/reservoir combo and go auto trans.

Other question which I think I know the answer to is: Does the GKT134 use the same PTO and the 420/465? Chelsea's catalog didn't include that trans for an option so I can't compare as I did with the 420/465.

The t-case bit I threw out before it was a suggestion, also along with tranny options....main thing I'm looking for is the specs on these hoists....what PSI/GPM/HP/RPM requirements do they have?

Thanks guys,

Chris

This will probably get me in trouble but here goes anyway.

Could you put a belt driven pump on the engine and a hydraulic motor on the lift input shaft? A 'hydraulic pto'? Thus the auto works just fine, minus the parking brake issue.

Not sure what kind of trouble you're expecting for your suggestion. Anything is fair game in my opinion.
It would depend on how much pressure and volume the lift requires. Pressure would be more critical than volume, because lower volume would just make it slower. But power steering works with a belt driven pump. One issue I see is that it would always be pumping unless you put some kind of clutch on the pulley (as is done with AC compressors).

I see it as an electric clutch on the pump, (like this: https://www.northerntool.com/shop/tools/product_200329776_200329776?cm_mmc=Google-pla&utm_source=Google_PLA&utm_medium=Hydraulics%20%3E%20Hydraulic%20Pumps&utm_campaign=Northern%20Tool%20and%20Equipment&utm_content=1081&gclid=Cj0KCQjwt5zsBRD8ARIsAJfI4BjPCzotZ_ogGTmfZefmuCOOvqoSPNjG9-39nqhywLnYAAik-z9cz5kaAoK0EALw_wcB)

Then no valve between the pump and motor, just hoses and a reservoir. The motor on the hoist runs all the time the clutch is engaged like a PTO would and the hoist is operated normally with the built in valve.

I expect that the speed of the hoist would be regulated by the pulley size and the gpm/pressure relation between the pump and the motor. Of course the pressure/gpm thing would have to be matched to the hoist needs. (PSI x GPM)/1714 = HP)

Weight of load at the center x lift at center gives foot pounds of work to dump. Divide by 33,000 x minutes to complete lift gives HP to lift. Slower lift equals less HP needed.

With a pto, as long as the parts are strong enough the lift gets done. With this setup, It would be good to know what is going on so as to not run too slow or blow something. The pressure in the 'pto' would not matter as long as it is within the ratings of the pump, hose, and motor. I would want the HP rating of the clutch, pump and motor to be able to carry the lift.

I suspect suitable parts might be available used.

If I was doing this for parades, I would likely go with something electric.

If I was going to use this a lot for real work, I think I would go with hydraulics.

I am not a hydraulic guy, I am an engineering technician and test water pumps for a living.

That is one I hadn't thought of....hydraulic pump running hydraulic motor running hydraulic pump. I have seen where guys used their PS pump to run a hoist, but with this one I didn't figure the volume was doable....now running a motor could be doable. Add a valve in the system to bypass the motor unless needed and poof....Hydro-PTO.

More to ponder anyway...thanks for the suggestion and discussion.

This will be for work, maybe 1.5 to 2 ton loads....nothing real big.

If it was my truck, I would do the math. Even a rough idea is way better than a total guess. Hopefully something will work out.

Agreed on the guess bit. That is why I'm looking for specs. I like to have, at the very least, an educated guess.

Simplest would of course be to run a manual with PTO, auto is just a convenience, the "HTO", shall we call it, is just an interesting proposition. It would of course require more research on what HP motor would be needed, flow of the PS pump or other pump, etc. More theory crafting.