Transfer case air shift hi lo

[Fredo Corleone]

Has anyone done a air shift for the hi lo gears in the transfer case? I think it would be more useful than the lever on the floor and a simple air cylinder with the correct throw would work pretty good.

 

[O.D. Fever]

It works the way it is. If you are a one armed man I can see the air shift. You might also consided power steering.

 

[gringeltaube]

..... a simple air cylinder with the correct throw would work pretty good.

Maybe.... if you never wanted it in NEUTRAL...


G.

 

[Fredo Corleone]

Maybe.... if you never wanted it in NEUTRAL...

I thought about the neutral thing if you shut off the air to the cylinder then using a manual lever to put it in neutral. I used to drive a Mack twin stick quad box and it just seems inconvenient to reach for the floor to pull out of low to high. I have seen others welding an extension to the lever but that gives it a long throw.

 

[clinto]

I don't think that would be a good idea. We've had dozens of these things and each one shifted a little differently, probably due to a number of factors like bearing/synchro condition, freshness of lube, etc. We've had some that just fell in and out of gear like a fresh Muncie and some that required "finesse". I don't think any manual gearbox, be it a transmission or transfer case, likes just being "forced" into gear before it's ready.

The air cylinder will know no such thing as "finesse".

Also, the phrase "unnecessary complexity" comes to mind.

 

[73m819]

Even though some THINK the transfer is a BROWNIE and should be treated as such, it IS NOT, It is not made to be used as one, split shifting ect. If it was the shift would be totally different, the internals would be different, IN A twin stick truck the TWO transmissions are MATCHED, work in sync with (complement) each other as far as the gear ratios, when you install a UNMATCHED trans or aux. trans, it makes for a VERY hard driving truck

 

[Fredo Corleone]

Some people follow the rules and some people make the rules

 

[Tlauden]

So what you folks are saying is its actually bad to use the hi/low to run as say a 7speed or similiar?? I didnt relise it was bad for the tranny

 

[vtdeucedriver]

Even though some THINK the transfer is a BROWNIE and should be treated as such, it IS NOT, It is not made to be used as one, split shifting ect. If it was the shift would be totally different, the internals would be different, IN A twin stick truck the TWO transmissions are MATCHED, work in sync with (complement) each other as far as the gear ratios, when you install a UNMATCHED trans or aux. trans, it makes for a VERY hard driving truck

Hey Ron,
I had to look it up in the TM to refresh my memory but no where did it say that you should not shift from high to low or low to high (IE Split shifting)

"The transfer may be shifted from low to high range at any speed by depressing the clutch pedal and moving the transfer shift lever up into HIGH position."

"When the terrain becomes hilly, soft or rough, and your truck is heavially loaded, a more efficient gear ratio can be obtained by moving the transfer shift lever from High to Low."
PG 2-51 TM9 2320-211-10 1977 printed M39 Series

The only warning in shifting is the downshift with engine rpm above 1800 rpm in the Multifuel.

 

[73m819]

Hey Ron,
I had to look it up in the TM to refresh my memory but no where did it say that you should not shift from high to low or low to high (IE Split shifting)

"The transfer may be shifted from low to high range at any speed by depressing the clutch pedal and moving the transfer shift lever up into HIGH position."

"When the terrain becomes hilly, soft or rough, and your truck is heavially loaded, a more efficient gear ratio can be obtained by moving the transfer shift lever from High to Low."
PG 2-51 TM9 2320-211-10 1977 printed M39 Series

The only warning in shifting is the downshift with engine rpm above 1800 rpm in the Multifuel.

Still NO WHERE does it say it is ok to drive as a twin stick, the dropping into low is for "When the terrain becomes hilly, soft or rough, and your truck is heavially loaded, a more efficient gear ratio can be obtained by moving the transfer shift lever from High to Low." not split shifting, and when the need for low is no longer needed then the shift to high, again not split shifting. the transfer is not designed for the constant shifting that split shifting calls for.

 

[patracy]

I've never known the TM's to lie. I've known others to form their own opinions though.

 

[vtdeucedriver]

Well from personal experience with my M52A2 and my M127 with a 6 ton load on paved roads, It was not performing to any respectable mechanical limits of the engine without starting any forward movement in low range. It was a good thing that it went from pavement to a soft dirt road at every stop light.

 

[shannondeese]

Call John at Stazworks. He built an airshift for his that has hi-n-L. He might be able to point you in the direction you're trying to go.

 

[Fredo Corleone]

This is the Deuce hot rodding section if I BLOW up the transfer I will throw in another. Let's see what we can do with some air lines, duct tape and baling twine!

 

[m16ty]

Ron, I agree that you won't find out how to "split shift" in the TMs. It does help that they put syncros in the t-case though which lends itself to a pretty smooth split shift.

I split shift all the time and don't think it hurts a thing if done properly and not forced into gear when things aren't right.

 

[patracy]

Ron, I agree that you won't find out how to "split shift" in the TMs. It does help that they put syncros in the t-case though which lends itself to a pretty smooth split shift.

I split shift all the time and don't think it hurts a thing if done properly and not forced into gear when things aren't right.

Bingo.

You shift a syncro'ed transmission up and down all the time don't you? Since the t-case is syncro'ed, it to can be shifted on the fly as well. It's the same principle at play.

Actually the Brown-Lipe/Brownie Box came in two flavors, a highway (syncro'ed) and a off road (non-syncroed). Again, totally the same concept at play.

<---Split shiftin' deuce driver. And I'll keep on!

Edit:
When I swap the transmission in the wrecker, you better believe I'll be split shifting it too! You think that 3rd to 4th shift is a hole in a deuce? Try it in a LDS powered 34,000 lb vehicle!

 

[m-35tom]

Even though some THINK the transfer is a BROWNIE and should be treated as such, it IS NOT, It is not made to be used as one, split shifting ect. If it was the shift would be totally different, the internals would be different, IN A twin stick truck the TWO transmissions are MATCHED, work in sync with (complement) each other as far as the gear ratios, when you install a UNMATCHED trans or aux. trans, it makes for a VERY hard driving truck

yes maybe, but it is syncro so was obviously meant to be shifted on the fly. also the 3053 was just a quick adaptation of the 3052 for the multifuel. with my OD kit it truly is a gear splitter and very useful. unimog has air shift on their OD add on unit for the 435's works well and is used as a gear splitter. you just need 2 air cylinders and some interlocks, pretty simple.

tom

 

[quickfarms]

These trucks were designed to be driven by soldiers. It looks like they were designed so they could be shifted on the fly or split shifted. Most were not taught this because it may have been considered to complex for the average soldier.

The TM does not say it should not be split shifted which is just as important.

 

[novajohn]

i rember grabing 5 low instead of 3 hi for the 3 mph extra in the mountains of oregon

 

[desertfox]

Let me put this info to the drivers. While in Viet Nam and driving deuces when getting up to speed was essential, I/we would place our left arm through the steering wheel and shift the transmission and shift the transfer case with the right just as fast as possible. In an attempt to be a difficult moving target. It became second nature and smooth. The trucks performed very well without malfunctions. Well, except when an FNG got behind the wheel. Most of us have been there done that. We gotta start somewhere.