"Rescued" M816 Wrecker

[wcuhillbilly]

Glad I could be an inspiration to you. (82 chevy 3+3)
Mine used to be state dot yellow too, had a couple gallons of green laying around one afternoon.
Bed is a shortened M105, with 6" out of the front, and 7-8" out of the rear, total 8' inside length, added a dump cyl underneath and now hauling gravel and firewood into the places that a Peterbilt wont fit... With the P-Pumped 24v Cummins driveline it hauls 2 tons of rock like its not even there...

 

[Csm Davis]

UV rated but the sun still breaks down the synthetic cable over time. Plan is to make a cover for the crane to protect it when not in use and extend it's life. Synthetic cable became approved for cranes a few years ago. This is a test run for using synthetic on one of these trucks and I'm not using the currently strongest synthetic cable option either, still much stronger than the steel cable though.

Downsides to the synthetic:
UV breakdown
Higher cost
Easier to cut

Upsides to synthetic:
Stronger
Easier to repair in the field
Safer if it breaks
Safer to handle
Lighter (floats on water)

The 1/2" IWPS steel cable is rated for 20-21k breaking strength. Synthetic I'm going to is 27k, current strongest is 32k. So with the crane rigged to a 3 part line as it currently is that gives a safety factor of 3:1 with the steel cable. With 27k synthetic rating that provides a 4:1 safety factor and with the 32k rating that gives a 5:1 safety factor. Means that the synthetic cable will not be working as hard as the steel cable was when lifting stuff.

Red have you asked about a factory installed sleeve, we had been talking with Sampson about that to prevent snags and sun damage on the first 20' or so, they do it on many winch cables.

Sent from my SM-G930V using Tapatalk

 

[red]

Haha before the m35a2 I had a 87 Chevy 3+3. Worked over 454, sm465 manual, np205, dually with a 9ft long flated sitting on 6" lift and 35"s. Sold it after partway through with a frame off rebuild and have missed having it.



New one is an 82 with the 6.2 diesel, th400, np205 dually. Plan is 2-3" lift, Humvee wheels/tires, locker in the rear axle. Most of the prep for moving the rear axle forward is complete and am waiting for the new shackle mounts to arrive either today or tomorrow. Will go through and repaint the frame later, just need to get it back together as soon as possible.



@Csm Davis didn't think about the outer sleeve for the crane cable.

 

[wcuhillbilly]

The 6.2 is a good economiser,. Before I swapped the Cummins in mine I had a 6.2 th400 for a short time,. The 400 was ok but it robbed the 6.2 of its fuel economy. So I swapped in the sm465/np204 when I converted mine to 4x4. Then found a GM3 mechanical waste gate turbo setup off a 93 GM 6.5. wow what a difference,. Put a ranger overdrive in and was getting mid 20s for milage... Another thought,. Hang a 40gal suburban fuel tank in the rear and get rid of the problematic tank selector valve

 

[red]

The 6.2 is a good economiser,. Before I swapped the Cummins in mine I had a 6.2 th400 for a short time,. The 400 was ok but it robbed the 6.2 of its fuel economy. So I swapped in the sm465/np204 when I converted mine to 4x4. Then found a GM3 mechanical waste gate turbo setup off a 93 GM 6.5. wow what a difference,. Put a ranger overdrive in and was getting mid 20s for milage... Another thought,. Hang a 40gal suburban fuel tank in the rear and get rid of the problematic tank selector valve

That's the fuel tank plan for it, suburban 40 gallon mounted behind the rear axle once I find one for a decent price ($300 between new tank and sending unit is too much right now). Averaged 18.6mpg cruising at 60mph with the stock 235x85x16 tires at roughly 2400rpm, stepping up to the 37"s will help that. Have a hx35 turbo sitting in storage that will eventually make its way onto the 6.2 but not for at least a year.

 

[red]

Scrap metal delivery!!




Still working on the flatbed for the pickup and needed some plate to mount the tail lights. So rather than drag the sawzall out there, figured I'd work in the shade haha. Yes, having a wrecker will spoil you.

 

[red]

Wrecker was busy over the past couple days. Was helping out at a event over the 4th and used the wrecker to tow in different vehicles for repairs. The extra weight by the front bumper helped alot with lift towing. Even with the m915a1 airborne could still easily steer whether on dirt or pavement.





Then today got some bad news. Sold off the extra pair of dump bed cylinders I had stored away and found out that they are slightly bent, so had to remove the 2 that were mounted on the m51a2 remains. And one of the hoses on the crane started to leak today while under pressure (slow steady drips).




Hose will be a fairly cheap fix (less than $100 after shipping) and have to drain the hydraulic tank soon anyways so not a big deal there. The dump bed cylinders is kind of a bummer.

 

[Another Ahab]

Hose will be a fairly cheap fix (less than $100 after shipping) and have to drain the hydraulic tank soon anyways so not a big deal there. The dump bed cylinders is kind of a bummer.

Stuff happens.

You wish it wouldn't but it does.

Sorry to hear about the bad news.

 

[wcuhillbilly]

That leak isn't too bad,,, my bed is perpetually covered in fluid from leaks that appear one day and disappear the next..... wish I had the money to tear it all down and do it right..

 

[red]

That leak isn't too bad,,, my bed is perpetually covered in fluid from leaks that appear one day and disappear the next..... wish I had the money to tear it all down and do it right..

Yea it's not too bad of a leak, only drips when the pump is engaged. Reconfiguring the hydraulics on the wrecker will be happening soon so I'll wait to replace that hose until that project begins.

Arranged to sell the dump bed and the front suspension from the m51a2 remains today, so decided that having a working tow light setup would be helpful. Finding the factory military cable is difficult and absurdly expensive. Since I'm not a purist by any means, decided to get rid of that plug and start setting it up for the standard 4 way flat trailer plug. Figured out which wires were ground, left, right, and marker. All 5 lights works.




Problem is I don't have the receptacle for the trailer plug yet and I'd rather not cut up the truck wiring unless necessary. And the turn signal relay on the truck doesn't work haha. Brakes and marker lights work fine.

 

[Another Ahab]

Arranged to sell the dump bed and the front suspension from the m51a2 remains today, so decided that having a working tow light setup would be helpful. Finding the factory military cable is difficult and absurdly expensive. Since I'm not a purist by any means, decided to get rid of that plug and start setting it up for the standard 4 way flat trailer plug. Figured out which wires were ground, left, right, and marker. All 5 lights works.

View attachment 689237

It almost looks like there's a fuse INSIDE those connectors, they're awful long.

Are those just standard crimp-on connectors?

 

[red]

It almost looks like there's a fuse INSIDE those connectors, they're awful long.

Are those just standard crimp-on connectors?

no fuse. crimped connectors with heat shrink built onto them, good quality and water tight

 

[Another Ahab]

no fuse. crimped connectors with heat shrink built onto them, good quality and water tight

Now THAT is slick.

Where do you get those?

 

[red]

Amazon https://www.amazon.com/gp/product/B01GXQMP66/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

Recommended by another member here, I like them.

 

[fasttruck]

Reference the crane not operating: The drive shaft from the power divider to the pump includes what the Army calls an "angle drive" in the shaft which seizes with lack of use. I Got one from Memphis Equipment nd as I remember it was not excessively expensive. Check -20P for description and part numbers.

 

[fasttruck]

Reference the crane not operating: There is what the Army calls an "angle drive" similar to a u joint in the drive shaft between the power divider and the pump which will seize and fail from lack of use. Think they would have put the pump right on the PTO and eliminate all that brick a brack ? I got one from Memphis Equipment and I don't remember it was real expensive. See -20 for part number and description.

 

[red]

Reference the crane not operating: The drive shaft from the power divider to the pump includes what the Army calls an "angle drive" in the shaft which seizes with lack of use. I Got one from Memphis Equipment nd as I remember it was not excessively expensive. Check -20P for description and part numbers.

Crane has been operational for about 2 years now. When I bought the replacement CV joint at that time it was $350 for a used joint (single). Now, the big retailers are listing the used single joints for over $2,000 each. That kinda price makes it more economical to make a modern PTO shaft like wcuhillbilly did, or relocate the hydraulic pump to right behind the tcase PTO which this truck will get soon.

 

[red]

Welp, looks like I'll need to find out a way to tow a 5th wheel with the wrecker. Won this at auction, planning for a camper build. 21ft long. No clue what the trailers designation is haha.




Thinking (for now at least) of just using some of the frame from the m51a2 and making it a removable extension to the rear of the wrecker, mount the 5th wheel plate onto that with the kingpin centered 4 1/2ft away from the rear winch fairleads.

 

[USAFSS-ColdWarrior]

Welp, looks like I'll need to find out a way to tow a 5th wheel with the wrecker. Won this at auction, planning for a camper build. 21ft long. No clue what the trailers designation is haha.

View attachment 689692View attachment 689691View attachment 689693View attachment 689694


Thinking (for now at least) of just using some of the frame from the m51a2 and making it a removable extension to the rear of the wrecker, mount the 5th wheel plate onto that with the kingpin centered 4 1/2ft away from the rear winch fairleads.

Current heavy wrecker designs have an attachment quite similar to your design concept. Here's a GOOGLE IMAGE SEARCH...

https://www.google.com/search?hl=en...0j0i5i30k1j0i8i30k1j0i30k1j0i24k1.colujwd6gvg

Look through the pics and you'll find some that are not the Boom Adapter, but an attachment with a fifth-wheel plate and coupler for snagging the king-pin.

 

[red]

The under reach setups are great on the modern wreckers but have 2 big downsides for me. Very expensive, and kill ground clearance.

The other common Holmes towbar setup can be used to tow a 5th wheel trailer but it limits how tight of a turn can be made, air connections are in the way on this trailer. Plus for towing a 5th wheel it just doesn't strike me as a strong and reliable way to connect to the kingpin, compared to a 5th wheel hitch.

So got me thinking. I have the 5th wheel from a m931, medium towbar, some 3/8" plate, and the frame from the m51a2. Figure a way to make a similar Holmes 750/850 towbar. flip the towbar around so that the feet are mounted to the square tubing that the outriggers slide in. Either trade the outer tube with the lunette ring on it for one with the pin, or cut the ring off and replace it with a pin end. Then attach the 5th wheel to that end of the towbar.