Cub Cadet BIG COUNTRY 4X2, Service Manual

4 X 2 Gear Selector

17

1.10.

The vacuum line marked with a blue dot pro-
vides vacuum to the actuator that controls 
the differential lock.  

The differential lock is 

engaged by a separate vacuum actuator.  The 
differential lock is disengaged by spring action 
when two conditions are met: (1) The differential 
lock solenoid is not activated and (2) If the differ-
ential lock was previously engaged, the speed of 
the rear wheels is equal.  The vacuum line with 
the 

blue dot 

should connect to the inner sole-

noid.  The inner 

(differential lock)

 solenoid has 

one yellow wire with a white trace 

and

 one 

green wire.                         

 See Figure 1.10.

1.11. Solenoid operation is as follows:

•

A vacuum manifold connected to the vacuum 
reservoir connects to the lower fitting on all three 
solenoids.  

•

The color-marked elbows connect to the upper 
fitting on each solenoid.  The vacuum lines that 
are connected to each solenoid by a color-
marked elbow lead from the solenoid to an actu-
ator.   

•

The orange and white wire provides power to the 
forward and reverse solenoids.  It should be 
“hot” whenever the key switch is on.  The sole-
noids are controlled by the presence or lack of 
ground at the other wire that connects to each.  

•

The differential lock solenoid has a constant 
ground, provided by the green wire.  Presence of 
current at the yellow and white wire triggers the 
differential lock solenoid.  

•

When energized, each solenoid will connect 
vacuum from the manifold (reservoir), through 
the color marked elbow, to its actuator. 

Figure 1.10

Dots:
red
green
blue

Forward           Reverse          Differential 
solenoid          lock solenoid

•

When the solenoid is de-energized, it provides a 
vent to the atmosphere to release the pull on the 
diaphragm.

NOTE: 

Because the differential lock actuator 

only pulls in one direction, the vent from the 
actuator is located in the plenum.                     
See Figure 1.11.

1.12. The 

vacuum reservoir (accumulator)

 holds a 

reserve supply of vacuum to operate the actua-
tor in low engine vacuum conditions. It is 
mounted to the top of the transaxle.                 
See Figure 1.12.

NOTE: 

One vacuum line connects the intake 

manifold to the vacuum reservoir. The other vac-
uum line connects the vacuum reservoir to the 
solenoids.  

Figure 1.11

Plenum

Starter relay

Vent tube for 
differential 
lock actuator

Figure 1.12

Vacuum (to solenoids)

       Vacuum 
       reservoir

Vacuum
(from intake manifold)