Differences M809 A0 A1 A2 A3 XX

[tucker79]

Wondering what the differences are between the models and what if any benefits one has over another. Are there any parts that can be used for upgrades from one model to another. I have done some research and haven't found all the info in one place. I think this would also be useful when looking to buy a truck to know if one is better than another for their needs. Im more interested in how this pertains to the M54s and M809s but most of the 5 ton talk has been about the M900s so all info is appreciated. So those in the know pass it on inquiring minds want to know. if there is a thread that has covered this please share it I cant find much

 

[MWMULES]

Never heard of an AO, A1, A2 or A3 in the M809 series and did you mean XM as never heard of XX either. The only two in that series were the early XM 809 and the M809 and the main diff in those was the grill all had same NH250 diesel motor.

• Model[SUP][12][/SUP]	Wheelbase	Length[SUP][a][/SUP]	Width	Height	Weight empty
  M813 Cargo	Long	26 ft 7 in (8.10 m)	8 ft 2 in (2.49 m)	9 ft 9 in (2.97 m)	21,020 lb (9,530 kg)
  M814 Cargo (long)	Extra long	32 ft 11 in (10.03 m)	8 ft 2 in (2.49 m)	9 ft 9 in (2.97 m)	23,540 lb (10,680 kg)
  M815 Bolster	Long	26 ft 7 in (8.10 m)	8 ft 2 in (2.49 m)	9 ft 8 in (2.95 m)	21,040 lb (9,540 kg)
  M816 Wrecker	Long	29 ft 7 in (9.02 m)	8 ft 2 in (2.49 m)	9 ft 4 in (2.84 m)	35,050 lb (15,900 kg)
  M817 Dump	Short	24 ft 1 in (7.34 m)	8 ft 2 in (2.49 m)	9 ft 4 in (2.84 m)	23,755 lb (10,775 kg)
  M818 Tractor	Short	23 ft 4 in (7.11 m)	8 ft 2 in (2.49 m)	9 ft 4 in (2.84 m)	20,165 lb (9,147 kg)
  M819 Wreck/Trac	Extra long	29 ft 10 in (9.09 m)	8 ft 2 in (2.49 m)	11 ft (3.35 m)	35,065 lb (15,905 kg)
  M820 Expansible	Extra long	30 ft 3 in (9.22 m)	8 ft 2 in (2.49 m)[SUP]https://en.wikipedia.org/wiki/5-ton_6x6_truck,_M809_series#cite_note-14[/SUP]

  
  [TD]11 ft 6 in (3.51 m)[/TD]
  [TD]28,195 lb (12,789 kg)[/TD]
  
  [TR]
  [TD]M821
  Bridge[/TD]
  [TD]Extra long[/TD]
  [TD]31 ft 10 in (9.70 m)[/TD]
  [TD]8 ft 2 in (2.49 m)[/TD]
  [TD]9 ft 6 in (2.90 m)[/TD]
  [TD]28,880 lb (13,100 kg)[/TD]
  [/TR]
  
  
  [*] With winch except M820 and M821.
  [*]https://en.wikipedia.org/wiki/5-ton_6x6_truck,_M809_series
  [*]The M54 was actually part of the M39 series and there was the M54, M54A1 and m54A2 , The M39 series were originally powered by a Continental R6602 engine, a 602 cu in (9.9 L) overhead valve inline 6 cylinder gasoline engine developing 224 hp (167 kW) at 2800 rpm. The -A1 upgrade had a Mack ENDT-673, a 673 cu in (11.0 L) turbocharged inline 6 cylinder diesel engine developing 210 hp (160 kW) at 2100 rpm. The -A2 upgrade had a Continental LDS-465-1A, a 478 cu in (7.8 L) turbocharged inline 6 cylinder developing 175 hp (130 kW) at 2100 rpm.
  

 

[simp5782]

Upgrades in which way? More power? Bigger? The NHC250 cummins in the M809 series is very reliable if respected. In my opinion more reliable than the multifuels. The pre M939s all have sprag operated transfer cases and I am not fond of those.

All of the trucks in the M39 and M809 series trucks are brutes and will do what they were intended to do. All day every day.

 

[fuzzytoaster]

MWMULES is right for the most part. There is no A0, A1, A2, A3 models like the M35 and M939 series trucks. There are M813A1 cargo trucks but they are dropside trucks, no change otherwise.


"The M813 and M813A1 cargo trucks have 7 x 14-foot (2.14 x 4.27 meters) flatbed boxes. The M813A1 truck has hinged dropsides with 147-1/2-inch (372.51 centimeters) access openings on both sides."

 

[Recovry4x4]

For that matter, there is no A0 in any series of military vehicles.

 

[tucker79]

I love the NHC in my M818 only downfall I see is the 3 to 5 MPG on the hi way. My M54 LTS 465 is awesome on MPG and love the whisler turbo but I worry about how many miles it has left in it. I am also not a fan of the sprag, one glitch in the actuator and its toast

 

[tucker79]

For that matter, there is no A0 in any series of military vehicles.

I had never heard of a A0 until I was reading a thread I cant find now and thats what inspired me to start this thread

 

[tucker79]

Upgrades in which way? More power? Bigger? The NHC250 cummins in the M809 series is very reliable if respected. In my opinion more reliable than the multifuels. The pre M939s all have sprag operated transfer cases and I am not fond of those.

All of the trucks in the M39 and M809 series trucks are brutes and will do what they were intended to do. All day every day.

Yes my 5 tons have always done whatever I asked of them and got me home without fail.
Sound like the A1 A2 A3 represents the what motor came in them and other than that they are the same.
Does tire size had something to do with the abbreviations?
I was more interested if there was any drive train differences axle splines, gear ratio, forwarding kit anything that could beef up these trucks a little more. The only trucks I know of are the wreckers, bridge, and rocket trucks that have bigger axles and have heard of a few forestry trucks that have air actuated lockers in the axles

 

[73m819]

If you want a BRUTE of a engine, the 6602, 602 cu in GASSER, tuned right, it WILL out torque both the Mack or the multifuel, these were a over the road engine when the 39 series were introduced, had as much as 1/3 more hp then the military engine and could be tweaked for more. This was one of the HOT TORQUE MONSTER engines in the late 40s (47-49, even into 50 -52)

 

[73m819]

I love the NHC in my M818 only downfall I see is the 3 to 5 MPG on the hi way. My M54 LTS 465 is awesome on MPG and love the whisler turbo but I worry about how many miles it has left in it. I am also not a fan of the sprag, one glitch in the actuator and its toast

"one glitch in the actuator and its toast"
NOT TRUE, the sprag and the case is nearly indestructible, NOT like the 939 case, the sprag is either ENGAGED or NOT engaged.
The sprag (overrunning clutch) design is a PROVEN design that has been around long before the building of the pyramids.

The sprag is simple, will work forever if taken care,
1 -- FLUSH the case with diesel till clean flush drains out.
2 -- FIX any air leaks in the f/r sifting system
3 -- CHANGE the shifting cylinder seals as soon as air is noticed at the exhaust ports of the poppet valves (this can be done with the case mounted in the truck).
Most people do not like the sprag because of issues that can be traced to not doing the above (this includes he military.

 

[tucker79]

"one glitch in the actuator and its toast"
NOT TRUE, the sprag and the case is nearly indestructible, NOT like the 939 case, the sprag is either ENGAGED or NOT engaged.
The sprag (overrunning clutch) design is a PROVEN design that has been around long before the building of the pyramids.

The sprag is simple, will work forever if taken care,
1 -- FLUSH the case with diesel till clean flush drains out.
2 -- FIX any air leaks in the f/r sifting system
3 -- CHANGE the shifting cylinder seals as soon as air is noticed at the exhaust ports of the poppet valves (this can be done with the case mounted in the truck).
Most people do not like the sprag because of issues that can be traced to not doing the above (this includes he military.

Good info and I have done all of the above from reading your threads and others
But the M818 air shift cylinder got hung up in reverse sprag I believe and without knowing it drove off in 1st and felt a lot of resistance like I was locked in all the time. so I disconnected the air supply, got sprag in N. n got it home 50 some odd miles.
Added a air shut off and dump and it does still work manually but but stays locked in, No 5% slip then auto engage so not sure whats going on with it but seems more complicated than it needs to be.
Loved it till it broke lol

 

[tucker79]

If you want a BRUTE of a engine, the 6602, 602 cu in GASSER, tuned right, it WILL out torque both the Mack or the multifuel, these were a over the road engine when the 39 series were introduced, had as much as 1/3 more hp then the military engine and could be tweaked for more. This was one of the HOT TORQUE MONSTER engines in the late 40s (47-49, even into 50 -52)

If the LDS ever goes in my M54 I got a BBF just waiting. Im a 7.3 guy n love them I would put one of those in but just thinking of the wiring involved makes my head hurt. This is supposed to be a fun hobby.

 

[red]

Yes my 5 tons have always done whatever I asked of them and got me home without fail.
Sound like the A1 A2 A3 represents the what motor came in them and other than that they are the same.
Does tire size had something to do with the abbreviations?
I was more interested if there was any drive train differences axle splines, gear ratio, forwarding kit anything that could beef up these trucks a little more. The only trucks I know of are the wreckers, bridge, and rocket trucks that have bigger axles and have heard of a few forestry trucks that have air actuated lockers in the axles

You're talking multiple generations here and seem to have gotten alot of info mixed up. So, let's straighten out the M809 series info since that's what you asked about.

All of the 809 series has the Cummins NHC 250 engine, Spicer 6453 5 speed manual, T-138 tcase, and the same 5 ton axles. There is no bigger axle that was installed in the wreckers. 6.44 axle gears, all but the m819 came with 11x20 tires. The M814 cargo has an A1 variant because of the dropside bed. The M820 has an A2 variant because of the hydraulic lift gate mounted to the rear of the truck. M820, M819, and M816 had reinforced frames. Single circuit air assisted hydraulic brakes.

Bridge trucks were the oddball.

Forestry service trucks were modified by them, unit level mods basically. When one of us buys these trucks and modify it for our use it's the same 'unit level mods', built to suit your purpose but it's not standardized.

 

[M813rc]

To be fair to Tucker79, a lot of folks on this site use the term "A0" for a little clarity when referring to the first issue of a truck, as in calling an M931 an M931A0 to differentiate it from an A1/A2.

While technically inaccurate, it is in a lot of threads one might come across. This can be confusing if you are new to the hobby or the site but doing what we always encourage - search the previous threads.

Tucker, I think also you have confused some M939 series 5-ton info in with your M809 info. The 939 series have the same NHC250 for the 939/939A1, and the 6CTA in the A2.

Cheers

 

[tucker79]

I thank you all for your input
I know my 79 M818 and 56 M54 pretty well and have spent 4 or 5 years reading the wealth of knowledge here the entire TMs on my trucks and others and would have never gotten these trucks to where they are today without you guys and this site. Still so much to learn, countless hrs of wrenching on these beast is still the best way to learn.
I wouldn't call myself newb but definitely no vet and was interested in expanding my knowledge outside the trucks I own so I can pass it on one day to others in need including myself as needed.
Iv been fixing my own stuff since my 1st bike chain fell off and own a bunch of older Civy med. & heavy trucks ( tree service) But these military trucks are just either before my time or just a whole nother animal.
Dying for a M37 its next on the list
Seems the A1 A2 A3 thing applied to the duces engine changes more than the 5 tons
But for example what I believe to be these A3 rims off a 2.5 I have would be a upgrade for a 2.5 I would think are there any other thing that would be more desirable in the 2.5 class

Pics for your viewing pleasure or horror depending on what way you go for dealing with my sentences that run on n on