nf6x
Feral Engineer
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- Riverside, CA, USA
I'm contemplating how I'd like to add a knuckleboom crane to my new M923, and I'm thinking about the PTO and engine speed governor aspects at the moment.
My first inclination would be to add a PTO hydraulic pump to the PTO mount on the transmission. I think I'd like to use an air-shifted one, either by adding an air shift cylinder to an M925 PTO or by picking out a suitable aftermarket PTO. I found this guide from Muncie with some useful background on PTOs:
Understanding Power Take-Off Systems
One of the cranes that I'm considering for my knuckleboom conversion is the Wajax/Palfinger PK19000M from the back end of an MK17 LVS rear body unit (RBU). If I recall correctly, the TMs I found on Scribd indicated that the MK48 front power unit (FPU) supplies about 11 GPM to the crane, so I presume that I'd need to provide a similar flow rate to power similarly-sized crane.
So, would a transmission PTO pump be suitable for this sort of hydraulic flow rate, or would I need to use a transfer-powered PTO like the M936 wreckers use?
I'd also want to govern the engine speed at a suitable constant rate for running the crane. My first inclination would be to retrofit the governor used on the M936 wreckers. I've learned a tiny little bit about those governors from the TMs and searching here on the site. I gather that the "VS governor" on the wreckers has a lever that should be pushed all the way forward or backward to engage/disengage the governor (or maybe vice versa), so it seems like it'd be easy to add on an air cylinder to actuate the lever.
Can any of y'all shed more light on what's involved in retrofitting the wrecker's governor to the existing engine in my M923?
It seems to me that it'd be nice to engage the governor with an air cylinder, too, so that the same dash-mounted control valve would engage the PTO and governor. An interlock with the gear selector and/or parking brake might be a good safety feature, and Mr. Google suggests that there are commercial PTO air shift controls that include air or electrical interlocks to disengage them automatically if the parking brake is turned off, for example.
BTW, I see there's another brand new thread asking similar questions about a deuce knuckleboom installation. I wanted to ask my questions in a separate thread since they involve a different kind of truck/engine/etc.
Any other brainstorming along these lines will also be welcome.
My first inclination would be to add a PTO hydraulic pump to the PTO mount on the transmission. I think I'd like to use an air-shifted one, either by adding an air shift cylinder to an M925 PTO or by picking out a suitable aftermarket PTO. I found this guide from Muncie with some useful background on PTOs:
Understanding Power Take-Off Systems
One of the cranes that I'm considering for my knuckleboom conversion is the Wajax/Palfinger PK19000M from the back end of an MK17 LVS rear body unit (RBU). If I recall correctly, the TMs I found on Scribd indicated that the MK48 front power unit (FPU) supplies about 11 GPM to the crane, so I presume that I'd need to provide a similar flow rate to power similarly-sized crane.
So, would a transmission PTO pump be suitable for this sort of hydraulic flow rate, or would I need to use a transfer-powered PTO like the M936 wreckers use?
I'd also want to govern the engine speed at a suitable constant rate for running the crane. My first inclination would be to retrofit the governor used on the M936 wreckers. I've learned a tiny little bit about those governors from the TMs and searching here on the site. I gather that the "VS governor" on the wreckers has a lever that should be pushed all the way forward or backward to engage/disengage the governor (or maybe vice versa), so it seems like it'd be easy to add on an air cylinder to actuate the lever.
Can any of y'all shed more light on what's involved in retrofitting the wrecker's governor to the existing engine in my M923?
It seems to me that it'd be nice to engage the governor with an air cylinder, too, so that the same dash-mounted control valve would engage the PTO and governor. An interlock with the gear selector and/or parking brake might be a good safety feature, and Mr. Google suggests that there are commercial PTO air shift controls that include air or electrical interlocks to disengage them automatically if the parking brake is turned off, for example.
BTW, I see there's another brand new thread asking similar questions about a deuce knuckleboom installation. I wanted to ask my questions in a separate thread since they involve a different kind of truck/engine/etc.
Any other brainstorming along these lines will also be welcome.
