Copyright by Goodheart-Willcox Co., Inc.
Chapter 9 Automatic Transmission Control Components 201
10
1. Screw—switch attaching
2. Lever—outer downshift
3. Nut—lever attaching
4. Washer—lever attaching
5. Switch—neutral start
6. Seal—downshift lever shaft
7. Lever—outer manual and shaft assembly
8. Seal—Manual lever shaft
9. Lever—inner manual
10. Nut—lever attaching
11. Lever—inner downshift
12. Rod—park pawl
13. Roller—lever actuating
14. Link—toggle operating
15. Clip—link retaining
16. Clip—link retaining
17. Clip—link retaining
18. Washer—link retaining
16
13
15
14
11
9
8
7
6
2
3
4
5
1
18
17
12
Figure 9-21. This illustration shows the outer and inner, case-mounted shift linkage. Also shown are the parking pawl, throttle valve
linkage, and neutral start switch. (Ford)
Parking gear
Parking
pawl
Shift lever
Figure 9-22. The parking pawl is simply a latch that locks into
large teeth on the parking gear. Since the pawl is mounted on
the case, the output shaft is locked to the case when engaged
and the vehicle will not roll. (Subaru)
pawl. The pawl then engages the parking gear, locking the
output shaft in place. The linkage also moves the manual
valve to neutral.
Shift-Brake Interlocks
All modern vehicles have shift-brake interlocks. The
purpose of the shift-brake interlock is to keep the driver
from moving the gear selector out of Park without pressing
on the brake pedal. This device keeps the vehicle from
being placed in gear accidentally or at high engine speeds.
Some older vehicles use a set of levers and rods connected
between the brake pedal and shift lever. Newer vehicles
have a solenoid on the shift linkage that applies a pin on
the shift linkage to keep the linkage from being moved.
Figure 9-23 shows a shift-brake interlock solenoid attached
to floor shift linkage. Figure 9-24 illustrates a shift-brake
interlock solenoid attached to column shift linkage. When
the solenoid is energized, it withdraws the pin and the shift
lever can be moved. A switch on the brake pedal linkage
energizes the solenoid. Sometimes the brake light switch is
used to provide an electrical signal to the body computer,
which energizes the solenoid.