M923 PTO help

[detroitmuscle1986]

So, I have a large hydraulic winch that I plan on mounting on the back of my 5 ton for hauling a hydraulic boat trailer up and down the launching ramp. I have done a little research on PTO options but haven't come up with much.. I see a few kits that are for sale that include everything necessary but it seems like the pto is not a reputable brand like Chelsea or so on and its also a cable operated pto vs air operated... Also what are the pro's and con's of having a transfer case vs transmission mounted pto. Any help or recommendations would be greatly appreciated. Thanks!

 

[M35A2-AZ]

Eric's always has fair prices on things.
http://www.eriksmilitarysurplus.com/potap.html

One thing I think is a down fall of the M939 is to use the transmission PTO the truck has to be in neutral.

 

[rhurey]

The TM for the 939 series lists the PTO as NSN 2520-01-105-6465 which lists manufactures as Dana Corp.

It's a PITA to mount, but other than that it's worked well.

 

[Bandit02]

Transfer case mounted PTO would only run when power is put into the t/case. Unless one of those aux gear turns if it's placed in neutral but you'd have to leave the truck in gear. Trans mounted is ideal but access is limited

I would think a cable actuated one would be best because you can gently engage it in neutral, while air just engages instantaneously, without a clutch to gently feather it on I could see damage to the PTO gears getting turned on so hard.

I'm going to run a winch on the front but an electric one like that 24V Warm Olympus model 25 (25000 lbs/12.5 ton), should be enough.

 

[74M35A2]

Options:
-24v electric pump, slow
-small gas engine powered hydraulic pump
-engine mounted belt driven clutched pump (NorthernTool, etc), use A/C compressor bracket to mount and drive it
-trans mounted 925 setup, pretty difficult to install but possible, clearance to frame near zero
-transfer case 936 setup, expensive and somewhat rare

All will need a hydro tank, valve, etc....

Can you just put a small gas engine hydro pump unit on the trailer itself? Not exactly sure of your config. Check with simp, as he has a setup mounted in his truck near same as you ar describing, though I don't think his is powered yet.

 

[Csm Davis]

So, I have a large hydraulic winch that I plan on mounting on the back of my 5 ton for hauling a hydraulic boat trailer up and down the launching ramp. I have done a little research on PTO options but haven't come up with much.. I see a few kits that are for sale that include everything necessary but it seems like the pto is not a reputable brand like Chelsea or so on and its also a cable operated pto vs air operated... Also what are the pro's and con's of having a transfer case vs transmission mounted pto. Any help or recommendations would be greatly appreciated. Thanks!

Not sure what you call a large winch? 20k off front of 5 ton is medium 45k is large.
What is a hydraulic boat trailer? And will it need hydraulic power from truck?
What are you calling a non reputable brand PTO? Don't know of any off brands made for the Allison Mt652 transmission in the 939 series trucks.
As to air or cable shift, if there is room on the PTO you choose it can be setup for whichever you prefer but I believe that the Chelsea has a clutch type PTO for air engagement. So you would need to start with the right PTO.
Not sure why you need an air engagement PTO, as the cable setup has been built into these trucks from day one.
I would think that the biggest reason for the transfer case PTO would be the size of pump you need for the winch you want. They will both be operating about the same.



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[detroitmuscle1986]

I will post pictures after work of the trailer setup. We took the bed off of the cargo truck and mounted a fifth wheel hitch. When you haul a boat of decent length say 40ft you need to disconnect the trailer from the truck and lower a set of hydraulic dolly wheels on the trailer. Then you use the winch to lower the trailer into the water and then pull it back up the ramp and re-hitch the trailer. This is done to prevent the truck from having to back into the salt water. The trailer has a 12v hydraulic pump that is run off of an alternator that we had to custom mount. Ill snap some pictures of the winch now. I am guessing that its in the 45k lb range. It came off of an old wrecker that was in northern maine. The gentleman who pulled the winch said that the truck was used for target practice and so there are some neat bullet scars on the winch housing.