40 years of the HMMWV, AM general video
- Thread starter Pacific Northwest yetti
- Start date
HUMMER/Expeditions
Well-known member
Beast !
11 years now, loyal, reliable, simple, capable. Dependable machine for me.
From 5 ft water crossing to 131 degrees heat, in Death Valley,
my humvee never left me stranded,
270.000 miles and counting
11 years now, loyal, reliable, simple, capable. Dependable machine for me.
From 5 ft water crossing to 131 degrees heat, in Death Valley,
my humvee never left me stranded,
270.000 miles and counting
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Fenderfour
Well-known member
Everything I hear from ex-military folks is how bad these vehicles are for reliability and longevity. Is this not correct? was all of it fixed? is it mitigated by modifications you have made to your truck?
HUMMER/Expeditions
Well-known member
The platform itself is bulletproof reliable,
However there are few simple modifications that is mandatory to do, otherwise it’s very unreliable,
Glow plug system MUST be changed,
Headlight switches gone
Transmission control system gone
Check valves gone
and few more
when those get modified NOT replaced with another bad design original part, then the vehicle becomes very reliable.
However there are few simple modifications that is mandatory to do, otherwise it’s very unreliable,
Glow plug system MUST be changed,
Headlight switches gone
Transmission control system gone
Check valves gone
and few more
when those get modified NOT replaced with another bad design original part, then the vehicle becomes very reliable.
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HUMMER/Expeditions
Well-known member
Most military trucks under military kid’s jurisdiction don’t last 7000 miles,
Perfect example is those heavy duty commins and cat powered trucks get engine replaced at under 8000 miles
The same engine under private party lasts over a million miles
Perfect example is those heavy duty commins and cat powered trucks get engine replaced at under 8000 miles
The same engine under private party lasts over a million miles
HUMMER/Expeditions
Well-known member
6.5
I bought the truck with blown engine of course. It came directly from the base in 2001 It had 11.000 miles, with 6.2 in there, and 3 speed.
I bought a used 6.5TD and 4 speed from predator motors in San Diego, at that time the used engine had 22.000 mikes.
My truck is serial number 4000 it’s one of the first production humvees, very light duty GVW is 7700 lb
Over the years I slowly upgraded the components to newer humvee parts. Right now it’s basically 10.300 lb GVW truck
Equivalent to H1
those Humvees currently at the auction blocks are 12,500 or 16,000 pound
GVW trucks. Much stronger than mine,
They still need all the usual parts modifications
Such as glow plug controller system, and other little things
HUMMER/Expeditions
Well-known member
One huge major factor to remember, is that military runs all their diesel trucks with JP8 and JP5 fuel, never diesel.
Jet propulsion fuel is equivalent to 76 octane gasoline how long do you expect the diesel engine to last under those conditions?
jp8 aviation fuel, not for diesel engines,
The injection pumps and engines don’t last long when run by JP5 or JP8
Jet propulsion fuel is equivalent to 76 octane gasoline how long do you expect the diesel engine to last under those conditions?
jp8 aviation fuel, not for diesel engines,
The injection pumps and engines don’t last long when run by JP5 or JP8
85_Ranger4x4
Well-known member
Jet fuel is more like kerosene than gasolene. I don't think the octane is near that high, kerosene is around 15.
It isn't the octane it is the lack of lubricity that causes problems.
Diesel fuel is similar to kerosene but isn't as "dry", it has things in it to lubricate the fuel injection system. In cold weather that "stuff" turns to gel... so for "winter blend" they blend in kerosene in to lower the gel point.
From the outside looking in I think a lot of failures could be explained by having to do what needs done in poor conditions and often with little to no mechanical sympathy.
I have a friend that has a humvee 6.5 pullout in his Ranger and he loves it. It lives on used engine oil.
HUMMER/Expeditions
Well-known member
Oh yes I definitely tried used motor oil and used ATF
it runs
I actually have a video on YouTube of 6.2 HUMVEE engine running on motor oil.
so I had a little bit of a JP8 that I drained from friends HUMVEE when he got it from the auction
I used it in a wood-burning stove to test out how quickly it combusts
It was very aggressive compared to normal diesel.
In some parts of the world, they run aviation fuel in carburetor engines.
And yes, you are correct. It’s very dry fuel. when diesel gets in your hands, it doesn’t evaporate but JP8 evaporates very quickly.
85_Ranger4x4
Well-known member
Oh yes I definitely tried used motor oil and used ATF
it runs
I actually have a video on YouTube of 6.2 HUMVEE engine running on motor oil.
so I had a little bit of a JP8 that I drained from friends HUMVEE when he got it from the auction
I used it in a wood-burning stove to test out how quickly it combusts
It was very aggressive compared to normal diesel.
In some parts of the world, they run aviation fuel in carburetor engines.
And yes, you are correct. It’s very dry fuel. when diesel gets in your hands, it doesn’t evaporate but JP8 evaporates very quickly.
Similar stuff in carbed engines used to be common here too, my 1946 John Deere B will run on diesel/kero. Starts on gas and switches over once warmed up. Has like 6.5:1 compression.
"tractor fuel" back in the day was way cheaper than gas. Now that the tables have turned I just run it on gas all the time lol.
2025 deleted member
Well-known member
How often do the portals need rebuilt?
HUMMER/Expeditions
Well-known member
Portal hubs generally don’t need to be rebuild, all the gears and bearings are in Oil bath, just like a differential they can last hundreds of thousands of miles, and they do, I have never rebuilt mine,
However the input and output seals will dry out and leak tiny amounts of gear oil on hot days .
Some ppl ignore it because the leak is so minor usually.
To replace output and input seal is about 35 minutes of a job very easy process,
HUMMER/Expeditions
Well-known member
Maybe we are old fossils to love this kind of engines
But how awesome is that you can start with gasoline and switch to diesel,
Don’t try that to modern Deer Motors.
I remember reading an old 4-Wheeler magazine where a reader's old 7.3l Powerstroke was his ideal choice because he could run it on aviation fuel up in Alaska. Always thought that was cool, but didn't know it could be detrimental!
You may have me looking for something I don't need on Facebook Marketplace later...
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