M936 operation question

[Up see tractor]

Hello all
I suddenly have an m936. I can't figure out how to make the wrecker bed work. I followed the instruction on the placards on the machine...what am I missing here?
Thanks

 

[Stonepicker1]

Look in TM 9-2320-272-10 under "Operation of Medium wrecker..Crane Operation...page 2-134...par 2-24.

Let us know after you read the TM if you still have problems.

 

[Coldfusion21]

The technical manuals (TM's) are sometimes thousands of pages, if you haven't read through them your missing a lot probably.

If you need help troubleshooting after that you've came to the right place, lots of experienced smart guys here!

 

[m16ty]

On the M936 I had, the PTO shifter lever was really hard to engage. You'd think you had it in but it wouldn't be. Shift it in and look up under the truck to make sure the driveshaft is spinning.

Another thing is the auto-throttle on my truck was messed up. At idle the bed wouldn't work. Does the rear winch work? It runs off the same pump.

You are shifting the transfer case pto in and not the trans pto, aren't you?

 

[Derrickl112]

At idle the bed wouldn't work.

You are not suposed to have the tcase pto engaged wile the truck is idling, according to one of the data plates.

Where in michigan are you? I have an m936a2!

 

[m16ty]

You are not suposed to have the tcase pto engaged wile the truck is idling, according to one of the data plates.

True. I think mainly it has to do with the trans not turning the transfer case PTO at low RPMs. I don't think it will tear anything up with the t-case pto engaged at idle. At least not for short periods.

 

[DKnoll]

I Have an M936 with a transfer case PTO that won't engage. I've tried the other tricks mentioned on SS, such as bleeding air down to below 30 PSI, or wiggling the transfer case lever to find a sweet spot. I've lubed the linkages, and when I follow the manual directions for engagement, the auto throttle rev's the engine to 1400 RPMs . Then, as the transfer PTO lever goes back to the rear wall of the cab, I feel and hear a gnashing of teeth, as if two gears won't remain meshed. Maybe the gears are completely worn? (some steel fragments on the drain plug magnet, but not much) Maybe some unusual resistance downstream at the hydraulic pump, that kicks back to the PTO? Any help is appreciated!

 

[engineer233]

Go under the truck andake sure your linkage at the PTO isn't bent. If not then pull the PTO off, restart the truck make sure the transfer case output shaft is turning. If it is then check the PTO shifter fork is not slipping. My shifter fork set screw had backed out and wasn't engaging the PTO.

 

[DKnoll]

Thanks so much, It will be awhile before I have time take off the PTO, but I will report back what I find.

 

[engineer233]

There is also a set screw on the gear that fits not the transfer case output shaft that must be tight to hold it into place. This had also backed out on mine. I'm not to far north of you so if I can be of help just pm me.

 

[DKnoll]

Here's an update to my recent transfer case PTO question. On my recently acquired 1984 M936, I still am working on getting the PTO to power the hydraulic pump: this truck had a MWO modification which added an automatic engine accelerator, which revs up when I engage the PTO lever. This is not in the TM. When I throw the lever, the PTO shaft to hydraulic pump begins to turn with steady, slow power. (yet I have no oil flow through the control valves of the crane, nor rear winch ………of course fluid level is full in the tank, and the filter arrow points to clean)

According to the TM, I should then put the transmission into 1-5. It is at this action that I get a grinding of gears, and the PTO rod backs out.

Does the MWO modification to the accelerator also obviate the need to throw the transmission into 1-5? I am surprised the PTO shaft to the hydro pump turns before the manual's final engagement step. On this truck, I am also surprised that I have zero hydraulic power/oil flow yet as I watch said PTO turn. This makes me wonder if the rear hydro pump could be entirely inop.

By the way, I do have function of the front winch via the transmission PTO, so the hydraulic oil is flowing from the reservoir through that different set of pipes.

Thanks in advance for your wisdom

 

[engineer233]

Make sure your transfer case is in neutral. If the truck is at idle it may not operate the boom or winch. The transmission will have to be in 1-5.

 

[DKnoll]

Yup, transfer in neutral. then I've tried both ways: PTO lever back, then 1-5 gear transmission, or vice versa. Same result, grinding of gears, like a clutch can't engage.

Never do get any power or hint of flow from hydro pump, even as the PTO to hydro shaft turns. I'll get some joy from it eventually. Just have to figure out what to replace

 

[engineer233]

Do you get the grinding noise without the PTO engaged and trans in 1-5 and tc in neutral? If no grinding then my best guess is it is the PTO . If the grinding continues without the PTO engaged try adjusting the tc shift lever as it may be still trying to stay in high range. If I was closer I would come and help. It's seems to be so much easier to trouble shoot with an extra set of hands.

 

[Scar59]

. If I was closer I would come and help. It's seems to be so much easier to trouble shoot with an extra set of hands.

Engineer,
I might take you up on that offer. Got a M936 last month and haven't had time to go over it yet. Working on it this weekend, addressing a couple hydraulic leaks first, then fluids and filters. The SS that recovered it and helped ship it said it worked OK. Biggest issue are leaks. Anyway, a knowledgable "soldier B" is hard to come by, wife says,"I am not soldier B". I'll be in touch.
JC

 

[whiskey357]

Welcome and congrats on the latest MV more to come later heheheh...Iffn the easy stuff doesnt work take it in to a repair shop.....they will find the problem for a couple of bucks ....had a shift issue with my M35A2.....not that smart on shifters so 350 bucks and a rebuild on the tranny good as new...even has a warrenty on it......so more the merry ...anyway welcome to the green bug bite club...