Video of all ways of shifting gears on an M 39 - G744 5-ton truck

[Robo McDuff]

Title says it all.

Just to help me and other confused newbies out. Can somebody with a video camera sit in a 5-ton truck from the M39 (also named as G744) truck series and go through the proper routine of shifting gears.

Stop laughing.

I do not mean 1-2-3-4-5 but all options, like when and how to shift between high low etc. Do you go Low 1-2-3-4-5 in terrain and only on highways H1-2-3-4-5, or low1 high 1 low 2 high 2 low 3 high 3 etc etc.

There are a lot of video's on shifting gears in the nice old 18-gear trucks.

up close

more advanced

funny but slightly overdone

Time to add an M39 video as well.

I think there are a lot of newbies out there who are not really sure about this, but too embarrassed to ask or think they know OK but are not using all possibilities of our trucks. I know I do still am. Too many new trucks have semi or full-automatics, just hit the gas, adjust your cruise control and fall asleep, the truck will do the rest (booooring).

So somebody please?


PS, while we are at it, in all three cases, I copied the video URL as web link. Only in the first case, it ended up like a video where you just click the forward arrow to play, in the other two links, it just showed up as a web link. Why these do not show up as video's ready to run?

 

[armytruck63]

When I had my deuce, I shifted like this: Low 2, Low 3, Low 4, Low 5, High 4, and High 5. Down shifting was the reverse of this pattern. I always shifted the transfer case first, whether I was upshifting or downshifting. You must start out in Low 1 if your truck has a sprague clutch transfer case.

I drove an M818 5-ton the same way and it worked great.

New truck has an automatic, so I guess I'm getting lazy in my old age.

There was a video posted that was taken in an M35A2 that shows the process.

 

[Robo McDuff]

When I had my deuce, I shifted like this: Low 2, Low 3, Low 4, Low 5, High 4, and High 5. Down shifting was the reverse of this pattern. I always shifted the transfer case first, whether I was upshifting or downshifting. You must start out in Low 1 if your truck has a sprague clutch transfer case.

I drove an M818 5-ton the same way and it worked great.

New truck has an automatic, so I guess I'm getting lazy in my old age.

There was a video posted that was taken in an M35A2 that shows the process.

To be honest, while on normal roads without load, until now I only used high 1-2-3-4-5, which seemed to work OK, never used low and did not knew until I read about it here that you could use the low selector also when at higher speed.

How do you shift low 5 to high 4? Clutch in and does not matter which lever or clutch in, everything in neutral, then in gears, then clutch up or ?????

Especially, how do you down-shift that pattern?

 

[ke5eua]

Here you go.

Not mine, but he has a very nice series on the deuce.

Only thing he say that is wrong is that they put 5th up to keep it out of the way. Incorrect, here is a good description of it:


All deuces with the 5th gear toward the dash are overdrive units. In a direct tranny (no overdrive) 5th gear is coupled to the input shaft, witch is the smallest gear on the top shafts ("normal" shift pattern). An overdrive tranny, the second gear back on the top shafts is the smallest, (this gear would be 4th on a direct), being smaller it turns faster than the input shaft, and you have overdrive. The stick being toward the dash is by no means for creature comfort, it is simply because Spicer used the same shift top on the direct and overdrive transmissions (this switches the last two shifts on most older truck 5 speeds, Spicer, Fuller, New Process, etc.). You have to remember the only ratios available for the Rockwell axles were 6.72, without overdrive you could only go as fast as you can now in 4th gear (direct).

Also, you can shift into 2nd at a stop then go into 1st. Going into 2nd allows the gears to slow down in the transmission.


http://youtu.be/HwNeUtf_ZQw

 

[armytruck63]

To be honest, while on normal roads without load, until now I only used high 1-2-3-4-5, which seemed to work OK, never used low and did not knew until I read about it here that you could use the low selector also when at higher speed.

How do you shift low 5 to high 4? Clutch in and does not matter which lever or clutch in, everything in neutral, then in gears, then clutch up or ?????

Especially, how do you down-shift that pattern?

The shift from low 5 to high 4 is easy: clutch in, grab transfer case lever and pull to high, grab transmission gear shift and shift into high four, let out clutch. It can be done easily with one clutch push. Downshifting is also one clutch push in, shift transfer down into low, and shift from fourth to fifth gear, let out clutch. Try it on your 5-ton and don't be afraid.

This knowledge can be really useful if you live in a hilly or mountainous area. Happy shifting!

 

[Robo McDuff]

BUMP. Maybe we can make a video of this at the GA rally?

The link of ke5eua only shows five-speed shifting in a deuce, not 10 speed shifting in a 5-ton. I am especially ointerested in the full possibilities of the 5 speed combined with this particular low-high gear.

 

[Floridianson]

I try not too over think it. 5 ton or Deuce on the road unloaded second low then second high and on up the rest in high. If I am off road she stays in low range.

 

[two.fiveM35]

Here is a video of shifting using low and high. When going from low 5 to high 4, always shift the transfer case first.

http://youtu.be/8IS5wL0Y42s

 

[73m819]

With the 36,000lb 819, I start out in 2 low, 3 low, 4 low, 5 low, 4 high 5 high, down shifting just the reverse, my reason for this is the MAJOR hole between 3 and 4, doing it this way seems to split the hole, also 36,000lb is a LOT for a single disk clutch. I believe the weight is what pulled the rivets out of the driving hub when I lost the clutch, thinking even 1 high was to high for the clutch. In the 819s case I think a 8 or 10 speed spicer would solve this issue.

 

[zebedee]

I think some searching or thread combining is falvour of the month...

http://www.steelsoldiers.com/showthread.php?98438-Split-shift-transfer-lever-extension/page2

http://www.steelsoldiers.com/showthread.php?90042-Split-shifting-a-813



Second thread, post #5 shows the TM extract with a "suggested" route for gear progression...

 

[bchauvette]

I don't have any deuce driving experience but plenty of Civi dump/tractor two speed axle experience. Will trade a MOG drive for a deuce drive. Other than 5th gear being right and up there shouldn't be that much difference.

Here is what we did:

1) High and low range where set and forget. On road high, off road maybe in sand pit or logging road, low.
2) First gear opposite reverse was "Granny Gear" or "Low one" used to get rolling when loaded.
3) Normal unloaded or light load shifting 2 thru 5 high range. A good driver should be able to tell if your lugging taking off in second. Using gears needlessly is counter productive and frowned on by the equipment owner, my dad .
4) When coming from a neutral clutch out situation to stop transmission spin shift into second then first. See #2.
5) Select proper gear first. Down shifting or "slamming" on a Hill or in the middle of a heavy pull situation will break something.
6) Double clutching up and down reduces transmission syncro wear.
7) You should be able to shift from 2nd to first by double clutching. See #5

when off roading, ice or snow it is possible to have too much torque. Some times 2 low or 1 high is in order.

The skill part of truck driving is knowing the personality of you truck. Knowing what gear selection and shift sequence for a particular on/oof road situation is part and parcel to that skill.

 

[mcmullag]

I ran around just in High till I saw the video or heard about this a couple years ago. So then, on steep hills in town I tried this hi low stuff and it worked okay going thru six different gearing set-ups a little better than the standard 5 in hi. I think it helps you split that big gearing gap between 3 and 4 in hi range.

 

[Floridianson]

Disagree with #5 if you don't down shift on a hill at the right time you will be climbing to the top in first gear.

 

[Floridianson]

Have to agree with Ron on the 816. I start in second low and run out all the gears in low then 4th and 5th high. I don't think of the 816 as a 5 ton more like a big brick of lead.