Does airshift affect speed/power?

[dm22630]

Does the airshift front axles affect speed/power?

I have 2 deuces with sprag that would BLOW the others off the road! They go up steep hills in 5th gear & wont drop below 55. NO loss of power when they are driven, and they feel like race trucks.

Is this a coincidence? Or does the sprag have something to do with it?

Thanks!

 

[Recovry4x4]

Purely a coincidence Siir

 

[maddawg308]

Perhaps a good follow-up question would be: what would cause the differences in power and speed in similar-type deuces, with the same equipment? All of my trucks have had C or D turbos (except for one, which will not be included here), airshift front axles, standard trannies and drivetrain. But some are ho-hum in the speed and power department, some will go well over 60 mph without breaking 2400 rpm. No rhyme and reason. I would think that trucks with the same parts would have the same results....

 

[gringeltaube]

Actually there are less gears and rotating parts in the T-136-27 Air Shift TC!
The difference I guess equals about 0.001% of total friction losses....

I concur with Kenny: keep looking for other reasons!

G.

 

[BFR]

Re: RE: Does airshift affect speed/power?

But some are ho-hum in the speed and power department, some will go well over 60 mph without breaking 2400 rpm....

we know how easy it is to turn up the fuel,
or replace dirty filters.... that can account for power diferences


I think sometimes we confuse consistency with accuracy in the guages in trucks...

 

[nf6x]

Re: RE: Does airshift affect speed/power?

But some are ho-hum in the speed and power department, some will go well over 60 mph without breaking 2400 rpm. No rhyme and reason. I would think that trucks with the same parts would have the same results....

Hmm, that doesn't make sense to me. I can easily accept that one truck would have more power than another due to differences in engine condition and/or tuning, but if the two trucks show different RPMs at a given speed, then either they're geared differently or at least one of the tachometers/seedometers is lying. It's been a while since I was on the freeway with one of my deuces, but with stock gearing and tires, shouldn't the engine be past redline at "well over 60 mph"? Do you have bigger tires on the "fast" truck?

 

[maddawg308]

RE: Re: RE: Does airshift affect speed/power?

No, I wish the reason were that simple. That truck was reading about 63 mph (I know the speedo only goes to 60, but I am estimating the "excess" that the needle was above the 60). Cars were passing me on I-81, but not very fast. All my trucks have 9.00x20 tires.

 

[Barrman]

RE: Re: RE: Does airshift affect speed/power?

To answer the original question, an airshift could be faster and more efficient.

A stock set up won't really be that much different going down the road. However, if you put lock out hubs on the front, then nothing in the front axle will be turning and neither will the front drive shaft going down the road. Just like a regular truck you will get better accellation, possible faster top speed up hills, longer life to the parts in the front drive train and less wear on the front drive shaft u-joints.

 

[Flea]

Perhaps the sprag trucks have the FDC bypassed? This would account for the extra power, and is more common than an upped fuel rate straight out of surplus.

 

[m-35tom]

believe what you want, but either your speedo or tach is wrong

 

[m16ty]

believe what you want, but either your speedo or tach is wrong

I agree.

 

[Jones]

Side note on air shift t-cases;
If you lose traction in the rear, the first thought/temptation is to reach for the air shift control.
DO NOT shift into front wheel drive "on-the-fly". Come to a full stop-- THEN shift.
Laying on your back in the mud/snow/unmentionable stuff isn't where you want to be doing t-case repairs.

 

[gimpyrobb]

Jones, you think driving down the road, and flipping the switch would do dammage also?

 

[dm22630]

Jones, you think driving down the road, and flipping the switch would do dammage also?

That is a constant fear I have. Some IDIOT riding with me thinking to themselves "what does THIS switch do??"....

I was that idiot at one time.....I had a suburban & showed my buddy that it could switch into 4 wheel drive why I was going 55mph......that was a costly mistake....

 

[Jones]

Gimpy and DM,
If the front and rear ratios are the same then the chance of damage should be minimal since the front axle is turning anyway due to the hubs being constantly "engaged". Only difference in "ratios" would be from unequal diameter tires due to tread wear. The damage comes from engagement with the front axle not turning at all, while the rears are spinning.
For what it's worth; the sprag t-cases are an overriding clutch (completely different design) as I understand it, and early deuces like the M135s and 211s relied on the front axle being slightly different (higher, I think) in ratio to the rears so that the rear axles had to slip a certain percentage before the front slowed down to run with them.