M816 Wrecker - General Questions

[Flyboy207]

Hello all,

I’m finally starting to get serious about finding an M816 to build. The idea would be to have a large off road recovery rig, capable of going into some rough areas, big enough to crane out broken off road race vehicles, and heavy enough to pull semi trucks that might be stuck in the sand or mud. My plan would be to add:
- Super singles (395’s look correct?)
- Turbo (855 Cummins’ are easy for us, we have a bunch of them in old Pete’s, and parts)
- Air brake conversion
I know these are “hot rod” mods and should be on the other forum, but I have some questions before I get into this up to my eyeballs:
How do these trucks do in rocks and mud? I know they’re underpowered and heavy, but do they have low enough gears, locking rear ends, etc?
Do metric super singles limit suspension travel?
How do the outriggers work/stow? Are they hydraulic?
Do they have hydro or air power steering?
And finally: does anyone have an M816 for sale in California that maybe needs some work?

 

[Mullaney]

Hello all,

I’m finally starting to get serious about finding an M816 to build. The idea would be to have a large off road recovery rig, capable of going into some rough areas, big enough to crane out broken off road race vehicles, and heavy enough to pull semi trucks that might be stuck in the sand or mud. My plan would be to add:
- Super singles (395’s look correct?)
- Turbo (855 Cummins’ are easy for us, we have a bunch of them in old Pete’s, and parts)
- Air brake conversion
I know these are “hot rod” mods and should be on the other forum, but I have some questions before I get into this up to my eyeballs:
How do these trucks do in rocks and mud? I know they’re underpowered and heavy, but do they have low enough gears, locking rear ends, etc?
Do metric super singles limit suspension travel?
How do the outriggers work/stow? Are they hydraulic?
Do they have hydro or air power steering?
And finally: does anyone have an M816 for sale in California that maybe needs some work?

.
Don't know about the super singles and limiting suspension travel - but the outriggers are manual. Pull them out, rotate them toward the ground, then use the screw jacks to lift the truck a fuzz.

Most 816's are manual steering or "Arm Strong" steering. By default, there are no lockers in the differentials. You don't want to bury yourself in mud if you can help it... Air brake conversion means new axles or a lot of custom fittings. 855 Cummins with a turbo might be really nice.

 

[WillWagner]

There is an 816 up for sale. It is a tow company vehicle based out of Santa Clarita, Ca, but, I think the truck is in Monterey Park. They have contacted the Museum about donating it to us, I did some looking. THEY think it is a 543, but it is an 816. It is a working truck, maintained for heavy recovery up in Lebec.

Message me and i'll send you a link, we tend to not post links here in the forums.

As for air brake conversion, it has been done by one guy here that I know of, @MyothersanM1. He has done an amazing job and it is all documented here on the site, here is a link,

M809-series (M818) Air Brake Retrofit

In this thread I will be discussing, hopefully in some detail, the conversion of my M818 to full dual circuit air brakes. I plan to post up as I progress with the installation. This mod should work for all M809-series and M39-series 5-ton trucks. The air assisted hydraulic brakes, as delivered...

www.steelsoldiers.com

Adding a turbo, that has been done multiple times as has adding Jakes. Best thing I can advise is look at the threads in 5t hot rodding, there are a bunch, and look at what others have done so some ideas start rattling around in your head, just remember, no piston cooling in the NHC that are in the 816, there aren't even provisions for the nozzles, so upping fuel rate is limited by that.

There is another option, the 900 series trucks. The 936A0/1 are NHC powered, auto trans, the A2 is Cummins 8.3l powered, turbocharged. The 855 is 855 CID, the 8.3 is 504 CID.

 

[Flyboy207]

Thanks Mullaney, thanks Will!

Regarding the 250, I’ve got one in a ‘63 Peterbilt that also has no piston coolers… I assume there’s no pyrometer in the wreckers, so I would add one to keep from sticking pistons, and not fuel it that hard. I think I’ll skip Jakes for hood clearance, but we should have manifolds and crossovers that will fit a turbo under the hood.

Steering, yeah I assumed they’d be manual. My deuce once tried to remove my thumbs just driving through a parking lot, so I might want to convert it to power.

A little disappointed that the outriggers aren’t hydro, but at least they’re there.

I read the air brake conversion thread a few years ago, seems like it’s not hard as long as I can get the axle parts. Really great write-up.

I did see the one in Santa Clarita, nice truck but out of my price range. I’m interested that he considered donating it, I’m a member of an aircraft and MV museum as well, I wonder if he’d give me a deal if I displayed it there.

There’s also one on GovPlanet right now… I’ve had a search term alert set for years, and finally got one… but I’m almost positive it will go way out of budget. There are about 40 people watching it apparently.

The 900 series wreckers are a little too new for my taste, despite all the benefits of them. I also assume they’re more valuable than the 800’s.

 

[Evil Dr. Porkchop]

The m816 has good power steering from the factory so no issue there. Another way to add air brakes is swap out the axles for ones from an m939 series truck. They bolt right in, and if you don't mind spending some more money you could try to find a USMC truck with Detroit Lockers in the rears. I lucked out and found a set locally for my m62 wrecker, for much less than the cost of conversion parts. The only downside is wedge brakes instead of s-cam, but that's not a big deal to me.

 

[msgjd]

As a bonafide (army) heavy motor transport-schooled long-term veteran 64C/88M, and later owner/OTR commercial operator of a number of M809-series (and commercial heavies) for a very long time, I can say the following with confidence ;

1: If you haven't already read threads elsewhere, you have to be extremely careful after putting a turbo on NHC250's
in the M809-series.. They have no piston coolers
a: If your truck is strictly for off-road recovery as you imply, then why need a turbo? The M809-series has
enough power for everything, EXCEPT maintaining highway speeds.. That is the only place where a turbo
on the NHC250 will help, and that's only for brief sessions, you have to adhere to the (new) pyrometer closely

2: If you instead put a (turbo) commercial-truck NTC855 in it, there's things you will seriously need to consider
a: The engine in these 6x6 trucks is offset to the right.. The oil filter on many commercial 855's will have full-blow
contact with the M816's frame .. Ouch
b: The commercial fan assy will likely be too high for the 6x6's radiator , you will have to swap things out
c: The hood will have to be modified to make room for the turbo crossover unless you fab a new relocated crossover
d: The air cleaner will have to be moved to other fender
e: The fuel shutoff will have to be replaced with a 24V one (likewise other electrical items too)
f: The oil pan may or may not have to be swapped , depending on how the commercial rig was spec'd
g: With heavy loads (and as the M816 is as-is) , the jack-shaft between tranny and transfer case is not
indestructable, such as a clutch dump at a stand-still or high application of torque while climbing.
Therefore, adding a NTC290 or larger will be an underlying problem for the jackshaft and perhaps
other U-joints and splines .. I know highway depts that have "been there, done that" and regretted it
h: If an NTC290 is a bit much for the OEM tranny in the M809-series, larger 855's will dynamite it.. Thus if
you keep the existing tranny, a great fit is the NTC230 if you can find one. Those pull hills better than a NHC250
and will not kill an M809-series' driveline. But you will still have to watch out for some of the other issues
mentioned above
i: If you wish to swap the tranny out to a commercial roadranger to make for a great selection of (road) gears,
that presents a separate long list of issues to consider, as well as severe modifications in order to retain the
powered front axle .. Personally I would never go to such expense in $ and time just to avoid the long-dreaded
"3rd-4th hole", or to modify an off-road work truck that is fine as-is for what it does

3: The M816 is the heaviest version of all the series. It will go into places farther and deeper with its 6x6 before it
gets stuck than it will if it wasn't a 6x6. I know that's a smartass answer, but is truth. Can't be stupid with them
unless you have a Cat D7E or larger if in trouble as deep as they can get and when self-recovery is
no longer an option .. That said, the 6x6's are better getting around than anything else on wheels their size
a: My wrecker is double-framed thus rather stiff on extremely-uneven ground but will warn me with creaks and
groans if I try extreme gymnastics. Wreckers are not as "nimble" as the other 6x6's but they still can do impressive
acrobatics that no normal highway rig can do
b: In your situation you're going to quickly find that the winch is your friend (as well as plenty of chains or other cable
if you can't get close enough to the victim. It's best to have two men when using the front winch, and it can take
three men just to spool out that massive rear winch in certain situations
c: The main lift hoist takes special care of operation. It cannot be abused or it will bend or break

Others have answered your other questions, except I see conflicting info about steering.. Any M816 (and all other M809-series) I own or have been around come OEM with regular hydraulic-type power steering.. Also, as was suggested, I concur a better retrofit would be to grab a turbo'd cummins from a later M939-series, however, I don't know if their crankshafts will accept a flywheel.. Years ago I ran into the crankshaft problem on certain automatic-tranny engines , when needing to fit them into a standard-tranny vehicle or machine

 

[DeMilitarized]

Hello all,

I’m finally starting to get serious about finding an M816 to build. The idea would be to have a large off road recovery rig, capable of going into some rough areas, big enough to crane out broken off road race vehicles, and heavy enough to pull semi trucks that might be stuck in the sand or mud. My plan would be to add:
- Super singles (395’s look correct?)
- Turbo (855 Cummins’ are easy for us, we have a bunch of them in old Pete’s, and parts)
- Air brake conversion
I know these are “hot rod” mods and should be on the other forum, but I have some questions before I get into this up to my eyeballs:
How do these trucks do in rocks and mud? I know they’re underpowered and heavy, but do they have low enough gears, locking rear ends, etc?
Do metric super singles limit suspension travel?
How do the outriggers work/stow? Are they hydraulic?
Do they have hydro or air power steering?
And finally: does anyone have an M816 for sale in California that maybe needs some work?

Buy an MTVR and convert it with a cheap wrecker body. Better in every way and [probably save money too.

 

[Flyboy207]

As a bonafide (army) heavy motor transport-schooled long-term veteran 64C/88M, and later owner/OTR commercial operator of a number of M809-series for a very long time, I can say the following with confidence ;

1: If you haven't already read threads elsewhere, you have to be extremely careful after putting a turbo on NHC250's
in the M809-series.. They have no piston coolers
a: If your truck is strictly for off-road recovery as you imply, then why need a turbo? The M809-series has
enough power for everything, EXCEPT maintaining highway speeds.. That is the only place where a turbo
on the NHC250 will help, and that's only for brief sessions, you have to adhere to the (new) pyrometer closely

2: If you instead put a (turbo) commercial-truck NTC855 in it, there's things you will seriously need to consider
a: The engine in these 6x6 trucks is offset to the right.. The oil filter on many commercial 855's will have full-blow
contact with the M816's frame .. Ouch
b: The commercial fan assy will likely be too high for the 6x6's radiator , you will have to swap things out
c: The hood will have to be modified to make room for the turbo crossover unless you fab a new relocated crossover
d: The air cleaner will have to be moved to other fender
e: The fuel shutoff will have to be replaced with a 24V one (likewise other electrical items too)
f: The oil pan may or may not have to be swapped , depending on how the commercial rig was spec'd
g: With heavy loads (and as the M816 is as-is) , the jack-shaft between tranny and transfer case is not
indestructable, such as a clutch dump at a stand-still or high application of torque while climbing.
Therefore, adding a NTC290 or larger will be an underlying problem for the jackshaft and perhaps
other U-joints and splines .. I know highway depts that have "been there, done that" and regretted it
h: If an NTC290 is a bit much for the OEM tranny in the M809-series, larger 855's will dynamite it.. Thus if
you keep the existing tranny, a great fit is the NTC230 if you can find one. Those pull hills better than a NHC250
and will not kill an M809-series' driveline. But you will still have to watch out for some of the other issues
mentioned above
i: If you wish to swap the tranny out to a commercial roadranger to make for a great selection of (road) gears,
that presents a separate long list of issues to consider, as well as severe modifications in order to retain the
powered front axle .. Personally I would never go to such expense in $ and time just to avoid the long-dreaded
"3rd-4th hole", or to modify an off-road work truck that is fine as-is for what it does

3: The M816 is the heaviest version of all the series. It will go into places farther and deeper with its 6x6 before it
gets stuck than it will if it wasn't a 6x6. I know that's a smartass answer, but is truth. Can't be stupid with them
unless you have a D7E or larger if in trouble as deep as they can get and when self-recovery is
no longer an option .. That said, the 6x6's are better getting around than anything else on wheels their size
a: My wrecker is double-framed thus rather stiff on extremely-uneven ground but will warn me with creaks and
groans if I try extreme gymnastics. Wreckers are not as "nimble" as the other 6x6's but they still can do impressive
acrobatics that no normal highway rig can do
b: In your situation you're going to quickly find that the winch is your friend (as well as plenty of chains or other cable
if you can't get close enough to the victim. It's best to have two men when using the front winch, and it can take
three men just to spool out that massive rear winch in certain situations
c: The main lift hoist takes special care of operation. It cannot be abused or it will bend or break

Others have answered your other questions, except I see conflicting info about steering.. Any M816 (and all other M809-series) I have or seen are OEM with regular hydraulic-type power steering.. Also, as was suggested, I concur a better retrofit would be to grab a turbo'd cummins from a later M939-series, however, I don't know if their crankshafts will accept a flywheel.. Years ago I ran into the crankshaft problem on certain automatic-tranny engines , when needing to fit them into a standard-tranny vehicle or machine

Thanks for the info! My main drivetrain concern that you listed would be the shaft between the trans and t-case. It would need to run down the highway for trips and parades, hence the turbo. I would only be looking at 270 or 280. I have an AirResearch turbo on my ‘63 Narrow Nose, I could think about running it, but I also have an HT3B laying around. An aftercooler from a small cam 350 would be a thought, but again, hood clearance. We have a plethora of intakes and crossovers for 855’s, I would bet there’s something here that could fit under the hood… but I’m just basing that on pictures, I haven’t seen one in person to check.

I wouldn’t plan on swapping a commercial truck engine into it, although we have a 335 and a 350 hanging around as well as some small bore 743’s. I wouldn’t particularly want an 8.3 either, in my experience driving 2 axle fire engines with ISC’s, they’re not much better.

Around here, it’s usually pretty obvious where the mud is and what to stay away from. Most of the recovery work/off road stuff I would plan on doing would be down in the desert or in the summer. It’s not going to be an actual front-line work truck, just a hobby. That said, I certainly would need time in the cab to know where to draw the “no-go” line.

I’m a little concerned about your comment on the boom. If you have advice or an operators manual (maybe in the TM’s forum?) to make sure I don’t mess anything up, I would appreciate it!

 

[Flyboy207]

Buy an MTVR and convert it with a cheap wrecker body. Better in every way and [probably save money too.

I should make the clarification that this won’t be a work truck, it will probably see more parades and grocery runs than actual recoveries. I totally agree that building an MTVR would be smarter, but that’s not the era of truck that I want.

 

[msgjd]

Thanks for the info! My main drivetrain concern that you listed would be the shaft between the trans and t-case. It would need to run down the highway for trips and parades, hence the turbo. I would only be looking at 270 or 280. I have an AirResearch turbo on my ‘63 Narrow Nose, I could think about running it, but I also have an HT3B laying around. An aftercooler from a small cam 350 would be a thought, but again, hood clearance. We have a plethora of intakes and crossovers for 855’s, I would bet there’s something here that could fit under the hood… but I’m just basing that on pictures, I haven’t seen one in person to check.

I wouldn’t plan on swapping a commercial truck engine into it, although we have a 335 and a 350 hanging around as well as some small bore 743’s. I wouldn’t particularly want an 8.3 either, in my experience driving 2 axle fire engines with ISC’s, they’re not much better.

Around here, it’s usually pretty obvious where the mud is and what to stay away from. Most of the recovery work/off road stuff I would plan on doing would be down in the desert or in the summer. It’s not going to be an actual front-line work truck, just a hobby. That said, I certainly would need time in the cab to know where to draw the “no-go” line.

I’m a little concerned about your comment on the boom. If you have advice or an operators manual (maybe in the TM’s forum?) to make sure I don’t mess anything up, I would appreciate it!

1: Listing all of your expected usages of a truck always helps the membership help you out .. Thanks for doing so...

2: The only location for a cross-pipe without hood modification is along the firewall across the rear head.. Adding jake heads is no issue except for the front head which would require a hood mod at the nose

3: I haven't seen a 270 in so long I forgot about those. The 270 and the 290 are okay for the M809-series as long as an operator is careful on the accelerator (and clutch).. Locally there was a 290-powered M818 (with retrofit 12yd dump) that hauled heavy and plowed roads for its PO.. It did well as long as the operator stayed mindful of the driveshafts .. I bought it for parts, it had a frame failure right where the PO notched the flats for the oil filter can

4: I have a 230, some 250's, a 290, a 315, and a 350 still in the yard , a few are still in trucks.. Had a 400 in an old Autocar that ran great.. When I was liquidating much of the business during a divorce I tried to sell it whole and then advertised just the engine, with no luck.. So i scrapped it (and many more old machines) when steel was $500/ton .. Got way more for scrapping the stuff than the advertised liquidation prices

5: Like you, I have some Holsets and jake heads kicking around just begging to go on the M817 and both M818's, all which haul heavy OTR but not as often nowadays.. I fight the temptation

6: The TM and wrecker-specific forums , both found here on SS, discuss the limitations of the boom.. They are capable of exceeding what the data tags say .. There are some on here who have discussed the results of that in depth .. I myself must've been close to damaging the boom a time or two , but you can hear and feel the strain enough to get your attention

 

[Flyboy207]

1: Listing all of your expected usages of a truck always helps the membership help you out .. Thanks for doing so...

2: The only location for a cross-pipe without hood modification is along the firewall across the rear head.. Adding jake heads is no issue except for the front head which would require a hood mod at the nose

3: I haven't seen a 270 in so long I forgot about those. The 270 and the 290 are okay for the M809-series as long as an operator is careful on the accelerator (and clutch).. Locally there was a 290-powered M818 (with retrofit 12yd dump) that hauled heavy and plowed roads for its PO.. It did well as long as the operator stayed mindful of the driveshafts .. I bought it for parts, it had a frame failure right where the PO notched the flats for the oil filter can

4: I have a 230, some 250's, a 290, a 315, and a 350 still in the yard , a few are still in trucks.. Had a 400 in an old Autocar that ran great.. When I was liquidating much of the business during a divorce I tried to sell it whole and then advertised just the engine, with no luck.. So i scrapped it (and many more old machines) when steel was $500/ton .. Got way more for scrapping the stuff than the advertised liquidation prices

5: Like you, I have some Holsets and jake heads kicking around just begging to go on the M817 and both M818's, all which haul heavy OTR but not as often nowadays.. I fight the temptation

6: The TM and wrecker-specific forums , both found here on SS, discuss the limitations of the boom.. They are capable of exceeding what the data tags say .. There are some on here who have discussed the results of that in depth .. I myself must've been close to damaging the boom a time or two , but you can hear and feel the strain enough to get your attention

I was looking through the TM earlier, I saw the info on using the winches and the boom, as well as the load limit plate and the instuctions for building the A-frame under the boom for heavy, long extension lifting...

I'll have to keep looking for the wrecker specific forum, either I'm blind or its hiding somewhere. I guess we'll see what I end up doing if I can track one of the dang things down.

Currently I've got a 1980 KW W900A in front of the shop doing some small things, I got it as payment for some work I did for a friend. 350 small cam, 5x4 set of sticks and walking beam in the rear. Hoping I can clean it up, send it down the road, and buy a wrecker with the proceeds.

 

[msgjd]

I was looking through the TM earlier, I saw the info on using the winches and the boom, as well as the load limit plate and the instuctions for building the A-frame under the boom for heavy, long extension lifting...

I'll have to keep looking for the wrecker specific forum, either I'm blind or its hiding somewhere. I guess we'll see what I end up doing if I can track one of the dang things down.

Currently I've got a 1980 KW W900A in front of the shop doing some small things, I got it as payment for some work I did for a friend. 350 small cam, 5x4 set of sticks and walking beam in the rear. Hoping I can clean it up, send it down the road, and buy a wrecker with the proceeds.

that sounds like a tuff truck with the walking beam, but depends on the brand.. I saw a 90's western star tear its Chalmers walking beam all to heck during a gypsum barge job.. Have a pic of that mess somewhere, with the wheels removed

I don't recall the model of the only kenworth i drove in 2008, but it was an early-90's rig with a lot of duct-taped busted plastic inside the cab such as levers and other things that would've been made of metal or heavier plastic in earlier years.. Even the metal mirror brackets were cracked, busted, and duct-taped. I wasn't impressed with that "quality".. It pulled fine though, and had a wetline. I rented it with an old talbert lowboy for a couple days. I bet your 80's KW was made of better stuff than the one i mentioned

 

[US6x4]

You can fit 3 jakes heads on there without cutting a hole in the hood:

https://www.steelsoldiers.com/threads/3-jake-heads-under-a-stock-m809-hood.195031/

 

[msgjd]

You can fit 3 jakes heads on there without cutting a hole in the hood:

https://www.steelsoldiers.com/threads/3-jake-heads-under-a-stock-m809-hood.195031/

thanks. i forgot i even had visited that string, notching the hood cross brace and doing the valve cover mod . The only thing that would bother me about notching the brace is whether the hood would collapse under a couple feet or more of heavy wet snow , it would easily be in excess of a couple hundred pounds plus the weight of the hood .. Flyboy207 doesn't have that to worry about though

 

[US6x4]

thanks. i forgot i even had visited that string, notching the hood cross brace and doing the valve cover mod . The only thing that would bother me about notching the brace is whether the hood would collapse under a couple feet or more of heavy wet snow , it would easily be in excess of a couple hundred pounds plus the weight of the hood .. Flyboy207 doesn't have that to worry about though

The brace would lose some strength but it would also bottom out on the valve cover after deflecting downward 1/4"+ or so. Probably not enough downward movement to permanently kink and deform the brace.

 

[Flyboy207]

Well… this happened considerably faster than I expected. I never thought this truck would sell within my price range, but I got it! It’s listed as a 1985 XM816, but if I understand correctly, the “X” prefix indicates it’s probably late 60’s? Only a few hours away from me, working on arranging transport now.


The auction listed it as “no guarantee” and not running, but having spoken with the owners, they say it will drive onto a trailer.


I do have another big question right now… what is this camouflage pattern? Is it MERDC? I’m slightly colorblind, but it seems like one of the colors is orange to me. I was hoping for one in the NATO 3 color scheme, but if this is correct I would be willing to freshen it up.

It’s been over ten years of wishing I could find a wrecker, I’m pretty excited to get it home and check it over… and add it to my signature line!

 

[WillWagner]

Very cool! Yes, it is MERDC. Give me a bit and I can tell you what pattern it is. I love MERDC!

 

[WillWagner]

1 of 3 IMHO. The longer it sat, the harder it is to decipher. IMHO, Winter. Winter is Forrest Green, FG, 34079, 45%. Field drab, FG, 30118, 45%. Sand, S, 5%, 30277. Black, B, 5%. Could be Summer or Tropics, again, depending on the fading and how long it has been sitting in the elements.

MERDEC Camouflage Notes

 

[Flyboy207]

1 of 3 IMHO. The longer the sat, the harder it is to decipher. IMHO, Winter. Winter is Forrest Green, FG, 34079, 45%. Field drab, FG, 30118, 45%. Sand, S, 5%, 30277. Black, B, 5%. Could be Summer or Tropics, again, depending on the fading

MERDEC Camouflage Notes

Thanks Will! Might be an idea to bring it home and wipe some light oil on the paint and see if the colors brighten up.

 

[WillWagner]

Thanks Will! Might be an idea to bring it home and wipe some light oil on the paint and see if the colors brighten up.

Don't oil it, the oil will stay in the paint and make it a mess to deal with if you decide to repaint/touch up. Light wet sand it in a not very visible spot to see what colors it truly is. The wet sand can be used on the rear bumperettes and front bumper to get unit numbers. Those can tell you where it was last in service.

Some advice, IF you choose to keep it MERDC, Aervo paint is a bit sub par. The sand turns pink. Try and find Gillespie paint. The Federal paint numbers match almost perfectly. I did my MERDC deuce in Aervo, it was Grey Desert, the sand turned pink fast. I just kept a couple of cans under the seat. At car shows, when people were waxing their cars, I rattle canned mine!

I THINK the TM for MERDC paint patterns is here in the TM section, TB 43-0147 . If it isn't, I might have the copy here, Maybe I can scan to PDF and post it up