Power Flows

AUTOMATIC TRANSMISSION – ZF 5HP24

DESCRIPTION AND OPERATION 44-2-25

The planetary gear train is a single integral assembly which comprises the following components:

l

Three single planet carrier gearsets connected in series

l

A single sun gear

l

A twin sun gear

l

Three ring gears.

Power Flows
Operation of the transmission is controlled by the EAT ECU which electrically activates various solenoids to control 
the transmission gear selection. The sequence of solenoid activation is based on programmed information in the ECU 
memory and physical transmission operating conditions such as vehicle speed, engine load, throttle position and 
selector lever position.

Powerflow Schematic Diagram

1 Torque input from engine
2 Torque converter lock-up clutch
3 Transmission case
4 Planet gearset 1 carrier
5 Planet gearset 2 carrier
6 Input shaft sun gear – large
7 Planet gearset ring gear 1

8 Planet gearset 3 carrier
9 Planet gearset ring gear 3

10 Intermediate shaft sun gear
11 Input shaft sun gear – small
12 Planet gearset ring gear 2
13 Freewheel clutch

Gear

Input

Reaction

Output

Ratio

1st

Planetary gearset 2 and 3 via 
input shaft gear

Ring gear 1 and clutch 'F'

Planetary gear 3 carrier

3.57

2nd

Planetary gearset 2 and 3 via 
input shaft gear

Planet gear 2 carrier and ring 
gear 3

Planetary gear 3 carrier

2.20

3rd

Ring gear 1

Planet gear 1 carrier and ring 
gear 2

Planetary gear 3 carrier

1.51

4th

Planetary gearset 2 and 3 via 
input shaft gear and planet 
gear 2 carrier

Ring gear 3

Planetary gear 3 carrier

1.00

5th

Planetary gearset 2 carrier

Ring gears 1 and 3, Planetary 
gear 2 carrier and input shaft 
gear

Planetary gearset 3 carrier

0.80

Reverse

Intermediate shaft gear

Ring gear 2, planetary gearset 
2 carrier and input shaft gear

Planetary gearset 3 carrier

4.10

M44 1829

2

1

10

A

B

C

D

E

7

8

4

11

5

9

6

12

13

3