Learn from Chucky..., FMTV cab support tool

[Third From Texas]

Easy. Army maintenance bays have overhead cranes. They just pull the box off. Four nuts, a wiring connector, and the quick connect diesel hoses for the heater.

They have cranes on the HEMTT wrecker that could do it in the field.

Mostly though - they get rid of the trucks or have them depot level overhauled before they are old enough to have that problem. Turn that junk in and it either goes to auction or comes back out of Oshkosh as an A1P2 with electric over hydraulic cab lift.

Yeah, but I don't have any cranes.

And I need to rebuild my cab latch. I've had the kit for ages, but I'm at a loss for how to do it's safely. There's just not enough room in there between the box and cab with the spare down for me to work. And since Chucky's incident, I've been putting off the repair. But at some point it's got to happen soon (it's the next thing on the list so I can install my a/c ). I can park facing down hill and get the cab well beyond center, but I don't know what will happen when I pop off a hydraulic line in the configuration. I figure some brace will have to be required.

 

[chucky]

Yeah, but I don't have any cranes.

And I need to rebuild my cab latch. I've had the kit for ages, but I'm at a loss for how to do it's safely. There's just not enough room in there between the box and cab with the spare down for me to work. And since Chucky's incident, I've been putting off the repair. But at some point it's got to happen soon (it's the next thing on the list so I can install my a/c ). I can park facing down hill and get the cab well beyond center, but I don't know what will happen when I pop off a hydraulic line in the configuration. I figure some brace will have to be required.

Just jack it all the way over then stick a 4x4 post in a reel good spot for extra safety and you will be fine ! If i had jacked mine all the way over i would have had no problems ! Just make sure its scotched good !

 

[Ronmar]

Yeah, but I don't have any cranes.

And I need to rebuild my cab latch. I've had the kit for ages, but I'm at a loss for how to do it's safely. There's just not enough room in there between the box and cab with the spare down for me to work. And since Chucky's incident, I've been putting off the repair. But at some point it's got to happen soon (it's the next thing on the list so I can install my a/c ). I can park facing down hill and get the cab well beyond center, but I don't know what will happen when I pop off a hydraulic line in the configuration. I figure some brace will have to be required.

Bracing the cab is not really rocket surgury. If it will still raise pump it over the balance point and put a stick in there. On level ground with the cylinder fully extended you can disconnect any hydraulic line you wish as the cab is hanging mechanically on the fully extended cab lift cylinder. With the hydraulic system disconnected, there is of course nothing to keep a gang of hooligans from coming along and physically pushing the cab back over the balance point. Once raised, set the control valve to the lower position and go around and push for yourself, it is not easy to do…

but to keep this highly likely event from occurring, simply cut and install a crutch between frame and engine and rear of engine tunnel like seen in the pics.

if I had to work on the hydraulic cylinder, I would modify this slightly by using a slightly shorter crutch that keeps the cab on the lowering side of the balance point, i would lower the cab down onto it and then install a ratchet strap between cab latch and engine hoist bracket to hold the cab on the crutch. This would allow me to unbolt the hydraulic cylinder and any necessary mounting structure for maintenance/repair…

 

[coachgeo]

Bracing the cab is not really rocket surgury. If it will still raise pump it over the balance point and put a stick in there. On level ground with the cylinder fully extended you can disconnect any hydraulic line you wish as the cab is hanging mechanically on the fully extended cab lift cylinder. With the hydraulic system disconnected, there is of course nothing to keep a gang of hooligans from coming along and physically pushing the cab back over the balance point. Once raised, set the control valve to the lower position and go around and push for yourself, it is not easy to do…

but to keep this highly likely event from occurring, simply cut and install a crutch between frame and engine and rear of engine tunnel like seen in the pics.

if I had to work on the hydraulic cylinder, I would modify this slightly by using a slightly shorter crutch that keeps the cab on the lowering side of the balance point, i would lower the cab down onto it and then install a ratchet strap between cab latch and engine hoist bracket to hold the cab on the crutch. This would allow me to unbolt the hydraulic cylinder and any necessary mounting structure for maintenance/repair…

View attachment 919255

View attachment 919256

having had braced things that way before.... and had the brace slip right out nearly crushing me (thank god I moved fast)... I would not trust that. I can see the base won't move... cant see if the top would or not... pic is too dark... can't tell what it is.... which is where it moved in my situation

 

[Ronmar]

having had braced things that way before.... and had the brace slip right out nearly crushing me (thank god I moved fast)... I would not trust that. I can see the base won't move... cant see if the top would or not... pic is too dark... can't tell what it is.... which is where it moved in my situation

The top cannot move. The back wall of the cab comes down past the floor of the engine tunnel forming an inverted V when the cab is raised, to push any brace up into… onced pushed up into the V It locks quite well, had this one a little tight, was a little work to get it back out…

 

[coachgeo]

The top cannot move. The back wall of the cab comes down past the floor of the engine tunnel forming an inverted V when the cab is raised, to push any brace up into… onced pushed up into the V It locks quite well, had this one a little tight, was a little work to get it back out…

ahhhh perfect.... Ronmar for the win