Hydraulic dump cargo bed

[tobyS]

I want to make a cargo bed into a dump bed and found that my 923 has a hydraulic tank in front of the passenger side intermediate wheel and a pump with what appears to be a mechanical valve. The pump has the u-joint and female spline still intact but the male spline and power take off are not there. Since it is a rebuilt truck and the transmission shows signs of having been freshly reworked, I assume they must have removed the PTO and just pulled the spline, leaving the pump and valve.

Can an experienced hydraulic 900 series person explain how hard it will be to install a PTO and what linkage was original for control? I have no Idea what it may have originally operated, but it would power a cylinder for a dump if reconstructed, I believe. Cost is a factor.

 

[doghead]

Your truck is an 939 series truck (not a 900 series).

 

[js05]

I have a truck like that also. I think they use too have a winch on the front

 

[tobyS]

OK

Have you taken off or installed a PTO on a 923 (939 series) doghead? How hard is it and will I likely find one as salvage?

Your truck is an 939 series truck (not a 900 series).

 

[tobyS]

So at some point the winch was removed I guess js05. I'll look at the nameplate again. Some of the experienced members probably know how hard it is to come up with the parts to restore the basic PTO. I do a lot of Industrial hydraulics and use 24 vdc all the time. In fact the Siemens PLC's I use are mostly 24 vdc, as are the slave relays. Anyway...I need the motive power for a dump. It looks really tight to fit in a PTO, but is apparently possible.

 

[tobyS]

Why doesn't this site let me edit or reply? Really not very user friendly.

 

[m16ty]

You can find the PTO but I've heard it's a pain to install because of the tight space under there.

The PTO and valve control is two levers mounted in the cab next the the trans shifter. You can find a pic in the -10 TM. If I wasn't concerned with it being stock I'd just use commercially available cables like civilian trucks use. That would be easier to find and probably cheaper.

 

[tobyS]

Thanks m16ty, I found three or four sections in the TM that deal with hydraulics like you recommend. It was interesting to see that some wreckers use a PTO from the transfer case. But that means the tranny is turning, which I prefer not to do with the Allison. I'm not a purist like most people here, so keeping it original, other than for use or utility reasons, is not my goal. I have about 60 loads of brick building debris to haul from a town property to my farm. Dumps ready to go were a bit pricey and I like the 14' bed length. I think I've located a 4 stage cylinder and will use an industrial electric valve, but the PTO seems specific to matching the Allison transmission and with a pump already mounted, original seems the way to go. Note I've been looking at 24 vdc electric pumps from fork-trucks as an alternative or even clutch driven from the fan belt.