Question about airshift - Steel Soldiers::Military Vehicles Supersite

alphadeltaromeo · 11-28-2006, 15:32

For this newbie...how am I to know that a particular 2.5T has an airshift transfer by simply looking in the cab? Have a pic? Slowly but surely I'm being educated. If this is covered in a TM, I'm pleased to go look...just let me know

Andy

DDoyle · 11-28-2006, 15:41

There is a lever that is mounted to the bottom edge of the dash that - that lever is an air valve, flipping it engages and disengages the front axle.

Hope this helps,
David Doyle

alphadeltaromeo · 11-28-2006, 15:44

It surely does...thanks much David.

clinto · 11-28-2006, 15:53

The switch that is hanging directly under the instrument cluster (as seen below) is the switch in question. It should have a switch that goes from right to left and a bulb underneath (lights up when axle is engaged).

alphadeltaromeo · 11-28-2006, 16:01

I like the pic...helps considerably. With respect to locking the front...how often have you actually used it on your 4x4 adventures?

clinto · 11-28-2006, 16:04

Only once, but I have not off-roaded much with the truck since I got it. Sunday night, it climbed straight up a mountain of mulch....... Really impressive.

alphadeltaromeo · 11-28-2006, 16:08

Umm...lol...now don't tell me you don't have any...

Manstein · 11-28-2006, 18:00

Well, for this newbie... if it doesn't have airshift, what does it have and how does it work?

M1075 · 11-28-2006, 18:12

If no air shift, then you probably have a sprag (sprague) setup. There is also a kit to convert to manual shift with a level through the floor board. Try the search function for sprag and sprague and you will find plenty of info.

DDoyle · 11-28-2006, 19:31

Reo Motors designed these trucks to have automatic front axle engagement via an overrunning clutch - usually called a sprag. Whe the rear wheels spin, the front axle engages. When positive traction is restored to the rear axles, the front axle disengages. In about 1951 a particular officer - whose names escapes me at the moment - began a crusade agains the sprag unit. Reo Motors, GM (who used a similar system in their M135) and Aberdeen Proving Ground all began extensive testing - which showed repeatedly that the sprag unit, properly adjusted, worked exactly as designed. However, proper adjustment was critical.

After about 20 years of debate, the air shift transfer case was introduced - it was more expensive, and no more effective - less so in some cases due to driver error - but had reduced maintenance.

Funny, the 5 tons were never subjected to all this largely unfounded scrutiny.

Best wishes,
David Doyle