paradeduty
New member
- 727
- 28
- 0
- Location
- Chelsea, Michigan, U.S.A.
OK Gang - not sure if this should belong in the HOT RODDING section but here goes.
I need to relocate the Auxilliary Hydraulic Pump (for the Material Handling Crane (HIAB 650) and the Side Mounted Self Recovery Winch (Swiss Made)) on the 5-Ton HMTT (to be accurate - not HEMTT). It has become aparent that without major custom crafting and engineering, reattaching this pump to the front pulley of the engine crankshaft is not going to happen in my lifetime.
First and foremost is the lack of space. Originally, the pump sat in front of the engine and behind the flat perforated grill on the cabover. According to the trusty tapemeasure, less the length of the pump itself, this only leaves about 9 inches for a "pto" shaft and crank pulley adapter/yoke. Not a really easy shaft to have made. Then there is the issue of the crank shaft pulley itself. I did not think much about it, but my sources showed me that the threaded boss for an adapter to attach to on the pulley has 5 threaded holes where all of the available adapters they know of are 4 or 6 bolt. Alas, another custom adapter.
And all of the above would not directly correct the other problem - disengagement of the pump when cold starting/not in use. Originally, the truck used a prototype "magic gearbox" that was operated by air between the crank and the pump. I can just make out the shape of the gearbox in some of the pictures in the "manual". Unfortunately, the gearbox failed years ago and was not to be had when I picked up the truck. I could always pull the shaft or pull a "shearpin" whenever the pump is not needed - but re-alignment is going to be a pain.
All of this brings me to the point. With the TACOM (where it was built) show coming up this summer, I am trying to get the few things handled to get it back on the road (she runs great - 6V53T Detroit - starts on a dime). Now we come to the potential "hot rodding" part of the saga. The Allison in the HMTT is stated as being a model MT654CR. I have not been able (if there is any) to find out the difference between this and a MT654. The Allison Service Manual which is part of the original HMTT Manual is for a MT654 with no mention of a "CR"suffix. Should a "CR" be of note when concerning the trans? And if so, what does it stand for?
The reason that I ask is that I believe that the trans in the HMTT is the same as the one that came to be used in the 939(?) series 5-tons. What I didn't know until the other day was that the PTO access/mounting cover was on the passenger side not on the top as on the larger HT754 on the 10 ton wrecker. If it had been on the top as I thought, there would have been no room as the radiator on the HMTT sits BEHIND the cab over the transmission with a hydraulic fan (much as what came to be used on the LVS,PLS,and newer HEMTT/LVSR series all with radiators on top or on the side of the engines). But the side may have enough room. I can't imagine that the "CR" or not would have a difference in PTO options. Next question would be - who might have access to/for sale one of the 939 series front pto's. I believe the 5-tons used a divorced PTO and pump (using a PTO driveshaft) - I may end up looking for a "Married" pair to get things more compact.
Anyways - any suggestions would be more than welcomed!
Picture attached for those wondering what the **** I am talking about!
If you made it through reading this far, thanks. Dave.
I need to relocate the Auxilliary Hydraulic Pump (for the Material Handling Crane (HIAB 650) and the Side Mounted Self Recovery Winch (Swiss Made)) on the 5-Ton HMTT (to be accurate - not HEMTT). It has become aparent that without major custom crafting and engineering, reattaching this pump to the front pulley of the engine crankshaft is not going to happen in my lifetime.
First and foremost is the lack of space. Originally, the pump sat in front of the engine and behind the flat perforated grill on the cabover. According to the trusty tapemeasure, less the length of the pump itself, this only leaves about 9 inches for a "pto" shaft and crank pulley adapter/yoke. Not a really easy shaft to have made. Then there is the issue of the crank shaft pulley itself. I did not think much about it, but my sources showed me that the threaded boss for an adapter to attach to on the pulley has 5 threaded holes where all of the available adapters they know of are 4 or 6 bolt. Alas, another custom adapter.
And all of the above would not directly correct the other problem - disengagement of the pump when cold starting/not in use. Originally, the truck used a prototype "magic gearbox" that was operated by air between the crank and the pump. I can just make out the shape of the gearbox in some of the pictures in the "manual". Unfortunately, the gearbox failed years ago and was not to be had when I picked up the truck. I could always pull the shaft or pull a "shearpin" whenever the pump is not needed - but re-alignment is going to be a pain.
All of this brings me to the point. With the TACOM (where it was built) show coming up this summer, I am trying to get the few things handled to get it back on the road (she runs great - 6V53T Detroit - starts on a dime). Now we come to the potential "hot rodding" part of the saga. The Allison in the HMTT is stated as being a model MT654CR. I have not been able (if there is any) to find out the difference between this and a MT654. The Allison Service Manual which is part of the original HMTT Manual is for a MT654 with no mention of a "CR"suffix. Should a "CR" be of note when concerning the trans? And if so, what does it stand for?
The reason that I ask is that I believe that the trans in the HMTT is the same as the one that came to be used in the 939(?) series 5-tons. What I didn't know until the other day was that the PTO access/mounting cover was on the passenger side not on the top as on the larger HT754 on the 10 ton wrecker. If it had been on the top as I thought, there would have been no room as the radiator on the HMTT sits BEHIND the cab over the transmission with a hydraulic fan (much as what came to be used on the LVS,PLS,and newer HEMTT/LVSR series all with radiators on top or on the side of the engines). But the side may have enough room. I can't imagine that the "CR" or not would have a difference in PTO options. Next question would be - who might have access to/for sale one of the 939 series front pto's. I believe the 5-tons used a divorced PTO and pump (using a PTO driveshaft) - I may end up looking for a "Married" pair to get things more compact.
Anyways - any suggestions would be more than welcomed!
Picture attached for those wondering what the **** I am talking about!
If you made it through reading this far, thanks. Dave.
