New owner of a M 1084

[Mad Deranger]

Hello,

I just pulled the trigger on a 2000 M1084. Exceptional shape and I doubt the truck ever left Alaska. I signed up here at Steel Solders as soon as I put the deposit down a week ago and I have been cramming like a collage student before finals. I certainly know that old military trucks are a handful and I'm certain this is no exception. My PMCS on it today found the rear driveshaft out of phase and slight play of the spline. One of the u joint caps is trying to fly off being restrained by the cap lockplate. Rebuild time-Tiger tool on order. Air pump mount and alt mount "looked" ok with no obvious bolts backing out and a slight oil leak from the front left engine that I need to find. Fluids and lights OK . I didn't mess with CTIS, not till I'm home. I get her tomorrow early with a thirty mile ride home....at thirty miles an hour.

I have had my nose up this board's butt for the past week and let me say that this is the most laid back and straight forward bunch of "gearheads" I've read. Solid info and solid advice fast without excess yammering. I know I can make a go of this truck with you guys here, so Thanks!

The purpose of this truck is mainly the crane, wildfire tanker, and parades and will be kept mostly stock and she won't venture too far from home. I'll send pics when I get her home. Wish me luck.

 

[Godspeed131]

Congratulations on the new truck. I’m in the same boat as you. I bought mine around a month ago. Been doing a few things hear and there on the maintenance side. I had just replaced a few hydraulic hoses to get the crane back to working. Next will be, as you are doing, getting the driveshafts sent out for a good rebuild and balance. Good luck on it and have fun.

 

[wheelspinner]

Welcome to the crane club!

 

[Mad Deranger]

Well, I got the ol' girl home with no issues and I got the insurance company to insure it as a farm truck. Note the dog wondering how she is going to get in there. Defect report in next post.

 

[Mullaney]

Well, I got the ol' girl home with no issues and I got the insurance company to insure it as a farm truck. Note the dog wondering how she is going to get in there. Defect report in next post.

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Looks really nice!

Yep, the pup doesn't look so happy about not being able to go for a ride. Finally figured out my dog (about the same size as yours) is happy enough if I give him a plywood ramp to get in the truck. Took him a while to figure it out, but now he will willingly go for a neighborhood cruise with me. Gotta have a sidekick!

Can't tell much about the hydraulic lines from the pictures. I replaced most of mine because they looked pretty rough. The sun eats them. Don't scrimp on that. Sudden loss of fluid will make a really bad day...

Don't know how much of the TM's you have read, but remembering to stand the boom all the way up before you rotate is really important! The toolboxes on my truck have "beat marks" in them (before I got the truck). Not standing the boom up first is what causes that - in a big way.

Congratulations on your recovery!

 

[Mad Deranger]

Defects found: driveshaft as mentioned before (note the cap bolts working loose and a slight input shaft seal leak) and a whole lot of oil splatter around the rear axle. Enough to have the tires fling oil onto the crane. I suspect it is coming from this port in the picture. I think this is the CTIS relief valve and I remember a post on it. Leaking hub seal? Thirdly, the pressure relief valve at the wet tank actuates often. Pump pressure feedback line problems?
I'll poke about on the board here and see what has been said already and try to get up to speed. I think most of the problems I will find are from it sitting around too long.

 

[Mad Deranger]

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Looks really nice!

Yep, the pup doesn't look so happy about not being able to go for a ride. Finally figured out my dog (about the same size ans yours) is happy enough if I give him a plywood ramp to get in the truck. Took him a while to figure it out, but now he will willingly go for a neighborhood cruise with me. Gotta have a sidekick!

Can't tell much about the hydraulic lines from the pictures. I replaced most of mine because they looked pretty rough. The sun eats them. Don't scrimp on that. Sudden loss of fluid will make a really bad day...

Don't know how much of the TM's you have read, but remembering to stand the boom all the way up before you rotate is really important! The toolboxes on my truck have "beat marks" in them (before I got the truck). Not standing the boom up first is what causes that - in a big way.

Congratulations on your recovery!

I worked a HEMETT years ago back during my Guardsman's days before the FMTVs came out. I remember that warning too. The Hyd tank came empty so I don't know about the boom yet, but yes, arctic grade hoses are in the future. I bought the truck to replace my 40 year old truck and knuckle boom.

 

[Mullaney]

I worked a HEMETT years ago back during my Guardsman's days before the FMTVs came out. I remember that warning too.

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Cool deal! Just would hate for somebody to say nothing...
It would be pretty disappointing to say it nicely

 

[Ronmar]

Yea, the device in the 3rd pic is the CTIS dump valve(ised to steer airflow and vent tire air when lowering pressure). If it’s dumping oil from there, you have a hub seal issue. Also look closely at the axle vent line which runs up to a frame vent port in that area also. since CTIS is under pressure and the axle shouldn’t be, I would think that CTIS air would tend to flow into the axle and out the vent, carrying oil with it. Oil that makes it past the seal and into the CTIS gallery on the axle can enter the ctis system, but that is a lot of oil… a clogged axle vent could help force oil into the ctis gallery as the axle warms up and after a leaking seal allows ctis to pressurize the axle because of a blocked vent…

when you say relief valve at the wet tank do you perhaps mean the purge valve on the air dryer Immediately to the rear of the wet tank? It purges every time the compressor governor cycles off/unloads the compressor when the system reaches set pressure(125 PSI). The purge blows out water and oil collected by the dryer(blows it’s nose). If it is purging frequently just setting there idling, you got air leaks which are forcing the compressor back online to make up for the leaks and get the system back to set pressure…

 

[Mad Deranger]

Thanks Ronmar. It is purging from the dryer. From reading another post... and the amount of oil, it is likely the air is leaking via the CTIS and maybe a few places more. I am reading up on the older posts to get a handle on this. Is it correct that if I unplug CTIS control box the system will not pressurize to blow oil everywhere?

 

[SCM35A2]

Good looking truck!

 

[Mad Deranger]

Ooh...Just scored big on a crane remote. I am starting to compile a list of materials needed but I'll check in with you guys to make sure I got it all. I'll start a new thread on tools needed.

 

[Ronmar]

Thanks Ronmar. It is purging from the dryer. From reading another post... and the amount of oil, it is likely the air is leaking via the CTIS and maybe a few places more. I am reading up on the older posts to get a handle on this. Is it correct that if I unplug CTIS control box the system will not pressurize to blow oil everywhere?

Correct, unplug the controller and CTIS stops.

The easiest way to look for air leaks is to apply 120PSI of shop air to the front emergency glad-hand. This will charge the air system and allow you to look for leaking without the cat purring… chock the wheels, as applying air to the front emergency(red) glad-hand will also release the parking brakes, just like if the air was being applied from the trailer control of a towing vehicle.

 

[Third From Texas]

Good looking truck (and dawg) !

I modified one of those folding dog ramps my neighbor gave me to attach to the toolbox/step. Then I eventually added some folding feet to the ground end to reduce the angle of incline. I still need to add some carpet or something as my girl can't dig her nails in and is always hesitant to start up. But at the end of the day it still makes loading much easier and I don't have to worry about the jump down hurting her hips of anything.

Stows well in the bed side panel compartments or stowed behind the seat.

btw: I'm the unofficial yammerer of the group.

TRIXIE Two-Fold Dog Car Ramp - Chewy.com

Buy TRIXIE Two-Fold Dog Car Ramp at Chewy.com. FREE shipping and the BEST customer service!

www.chewy.com

 

[Mad Deranger]

Good looking truck (and dawg) !

I modified one of those folding dog ramps my neighbor gave me to attach to the toolbox/step. Then I eventually added some folding feet to the ground end to reduce the angle of incline. I still need to add some carpet or something as my girl can't dig her nails in and is always hesitant to start up. But at the end of the day it still makes loading much easier and I don't have to worry about the jump down hurting her hips of anything.

Stows well in the bed side panel compartments or stowed behind the seat.

btw: I'm the unofficial yammerer of the group.

TRIXIE Two-Fold Dog Car Ramp - Chewy.com

Buy TRIXIE Two-Fold Dog Car Ramp at Chewy.com. FREE shipping and the BEST customer service!

www.chewy.com

Hey! I like.

 

[Third From Texas]

Hey! I like.

You can find them in many sizes (some of the aluminum ones up to 8 foot).

https://www.amazon.com/dp/B01MSMCOPM

 

[Godspeed131]

Last week I welded up a frame for a ramp out of 1 inch tubing and in process of laying a sheet of aluminum over it for my dog and like you I made some brackets that rest on the inside of passenger step lip with the step folded up. I made it a little over 6 ft long and 19 inches wide with a taper at the top to fit in the step. It is wide enough I can store it in the bed side storage and it’s never in the way. I’ll probably post a separate thread when I get done with it with pictures.

 

[Mullaney]

Last week I welded up a frame for a ramp out of 1 inch tubing and in process of laying a sheet of aluminum over it for my dog and like you I made some brackets that rest on the inside of passenger step lip with the step folded up. I made it a little over 6 ft long and 19 inches wide with a taper at the top to fit in the step. It is wide enough I can store it in the bed side storage and it’s never in the way. I’ll probably post a separate thread when I get done with it with pictures.

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Nice! Heck, that might be really nice to have.
I'd like to see it for sure.

 

[Mad Deranger]

Well, after a week of ordering parts and tools and studying, stuff is flowing in. Kinda sort of... Today's project was to filter and fill the MHC Hyd system and check the crane operation. I filled it up and turn on the PTO. Sounds good, no spray or leaks but no response from any controls. I feel fluid passing through the manifold so I don't think it's a hyd problem other than air in the system. One thing I noticed was the power switch is a momentary on-off switch. I am not sure it that is to be so. The TM states it is a two position switch but that is vague. Fuse is OK.

I'm hoping Mullaney, Wheelspinner or somebody can tell me if the MHC switch in the rear is a constant or momentary on switch. I'm looking over the -20 TM and outside of checking for 24v input it's a dreaded DS item in the manual.
And two more questions. Does the 3126 share the killer oil tube problem also? and does the power diverter driveshaft have any issues like the drivelines?

 

[Godspeed131]

I had issues with my controls not working, with Suprmans help it wound up being the control solenoid lockouts on most all the individual functions causing the issue. here’s a link to that thread https://www.steelsoldiers.com/threads/m1084-crane-hydraulic-troubleshooting.189108/

The switch is not supposed to be momentary. It is a two position switch on or off, and always has power to it. If left on it will stay energized with power and drain the batteries so remember to turn it off when not in use.

The 3126 doesn’t have the governor oil feed line like the 3116 has.

Lastly From what I gather, the drive shaft isn’t as susceptible to the same issues as the fronts or the 1078’s rear. It’s the angle of the shafts that kill them I believe. The front and rear on mine has bad slip joints that I’ll need to get addressed soon, but my intermediate is fine. I’m going to take all of them out regardless and have them over hauled at some point