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I'm going to inspect the crane hydraulics of a M936A1 that is reported to not work and I want to get knowledgeable on crane ops before I go see it . All I know is "PTO engaged but no hydraulic pressure to crane" so I'm guess this has a high probability of operator error. And yes, I have all the TMs. Even posting the crane ops section from the -10 here as I'm sure in the someone in the future will google this post who just bought a wrecker but never looked at the TM will wonder they can't get the crane to work. But I digress....
Here are my questions:
-After reading through SS and the TMs, I still can't get a good understanding of how the engine and transmission is supposed to operate together when the crane transfer case PTO is engaged. Per TM, the order of steps are: 1) shift t-case to neutral, 2) shift tranny to 1-5, and 3) set engine rpm to have hydraulic power. I see a lot of posts about the tranny up shifting gears when in 1-5 but I can't determine from the TMs if the transmission is supposed to up shift once the rpm is set. I've even seen folks say to use other ranges like 1-4 or go straight to 1-1. Does the tranny stay in first gear or actually up shift? How does this effect the PTO speed? I guess I'm really trying to understand how the tranny and transfer case PTO interact to power the crane pump.
-How can I tell if a truck has the auto-throttle MWO (but not functioning)? What would the device look like and where would it be located?
-I'll inspect all linkages for bent rods, etc. but I know there are a lot of interlocks and other things to worry about too. Is there is a particular one I should look at if I have trouble getting the transfer case PTO to engage? Any tricks not explained the TM that help since the -10 is really thin on troubleshooting? The one trick I've seen is to bleed down the air pressure to work around a bad t-case interlock air solenoid or cylinder. Anything else?
That's a lot of questions for now before I even see the truck so appreciate the education. Will keep y'all posted of what I find.
Here are my questions:
-After reading through SS and the TMs, I still can't get a good understanding of how the engine and transmission is supposed to operate together when the crane transfer case PTO is engaged. Per TM, the order of steps are: 1) shift t-case to neutral, 2) shift tranny to 1-5, and 3) set engine rpm to have hydraulic power. I see a lot of posts about the tranny up shifting gears when in 1-5 but I can't determine from the TMs if the transmission is supposed to up shift once the rpm is set. I've even seen folks say to use other ranges like 1-4 or go straight to 1-1. Does the tranny stay in first gear or actually up shift? How does this effect the PTO speed? I guess I'm really trying to understand how the tranny and transfer case PTO interact to power the crane pump.
-How can I tell if a truck has the auto-throttle MWO (but not functioning)? What would the device look like and where would it be located?
-I'll inspect all linkages for bent rods, etc. but I know there are a lot of interlocks and other things to worry about too. Is there is a particular one I should look at if I have trouble getting the transfer case PTO to engage? Any tricks not explained the TM that help since the -10 is really thin on troubleshooting? The one trick I've seen is to bleed down the air pressure to work around a bad t-case interlock air solenoid or cylinder. Anything else?
That's a lot of questions for now before I even see the truck so appreciate the education. Will keep y'all posted of what I find.
As I move the crane with a load I keep an eye on the gauge I added at the valve block I have the relief set at 1350psi I should not be riding the relief