traction booster

As others have mentioned, it's Allis's method of draft control - pivot and lift points are such that it senses the load/pull on the hitch arms and lifts the implement slightly when too much drag is encountered. Usually it just lifts an almost imperceptible amount - enough so the tractor is taking all the weight rather than some of it resting on the soil, and thus there's more weight (and thus traction) on the rear axle, so it can power through the tough spot. If it keeps sensing too much pull, it will keep lifting, raising the implement out of the ground and thus pulling less. Although all manufacturers developed their own draft control systems, Allis really pulled out all the stops on theirs and did a great job on it. They also designed it so you could have the traction booster aspect work at the remotes for trailed/pull type (not mounted) implements: You hitched it to a special drawbar they offered that hooked across the three point lift arms. Because the load is sensed by the pull at the lift arms, it would sense the pull of your trailed implement. By having the control levers in the right position it would then send fluid to the remotes when it sensed too much load rather than lift the hitch, and would lift your trailing implement using the implement cylinder. I don't think any other manufacturers offered that ability.

Here's what the operator manual says for the 180 (it didn't copy too well):

The lever located nearest the wheel guard controls the tractor lift arms and is us ed to lower and raise mounted or semi-moumted implements

from transport position to working position and

vice versa. This lever has four positions, "Lift" , "Hold" ,

"TRACTION BOOSTER" and " Lower". When

the lever is moved rearward it will detent in the "Lift" position and as the lift rams fully extend the pressure build-up will release the detent and the centering spring will return the lever automatically to "Hold 11 position. When the lever is moved to the extreme forward position the valves in "Lower'' position and must be manually held in this position, slowly releasing the lever w ill return it t o the ''TRACTION BOOSTER" position which is a detent.

The lever must be manually moved to any other

position. The system will lower or raise the draft arms

at a faster rate in the' Lower' position than in

the "TRACTION BOOSTER" position. In order

to raise or lower in the "TRACTION BOOSTER"

position either the TRACTION BOOSTER or

Position Control lever must be moved.

TRACTION BOOSTER OPERATION

The advantage of weight transfer for added down-

ward load on the tractor wheels, efficient sus-

pension of the implement and the controlled depth

of the implement operation, have all been combined into the term "Allis - Chalmers TRACTION BOOSTER System" .

The rear lever nearest the wheel guard controls the TRACTION BOOSTER system. When using the TRACTION BOOSTER system with feedback, operate tractor with the levers positioned as follows: The lift arm control lever must be in the TRACTION BOOSTER detent position. The Position Control lever must be

moved forward, in the deepest, highest number

position. Select desired depth of implement

with the TRACTION BOOSTER lever.

TRACTION BOOSTER with f e ed- back controls

the implement depth to maintain a near constant

load or pull on the draft arms. In varying soil

conditions when tighter soil is encountered the

TRACTION BOOSTER system will automatically

sense the increase in load (pull) and raise the

draft arms slightly to maintain a constant load.

When loose soil is encounter ed the load will

lessen and the TRACTION BOOSTER system

will automatically lower the draft arms to pick

up more load to maintain a constant load. The

TRACTION BOOSTER system with feedback,

works to maintain a near constant load not a

constant depth . However , if the soil is not too

varied it will maintain an essentially constant

depth.

When a more constant depth is desired in widely

varying soils, it may be necessary to move the

TRACTION BOOSTER lever to a lower number

setting when encountering loose soils or to a

higher number setting when encountering tighter

soils. After passing through the tight or loose

soil return the TRACT ION BOOSTER lever to the original setting. In most operating conditions this procedure is not necessary.

TRACTION BOOSTER is generally used with all

implements that operate in the soil, such as

moldboard plows, disc harrows, bedders, etc .

The TRACTION BOOSTER system will maintain

a more const ant depth when set for maximum

feed - back. Refer to "Feed-Back Linkage" m

the 11Adjustments 11 section of this manual.

POSITION CONTROL

The rear lever nearest the operator controls the Position Control system. When using Position Control only, position the control levers as follows: The tractor lift arm lever must be in the TRACTION BOOSTER detent position .

The TRACTION BOOSTER lever must be moved forward, in the deepest, highest number position. Select any lift arm height with the Position Control lever to control the working position of the implement.