ZF 3HP transmission explained

3HP 12 · 3HP 22
Production:	1963–1975 · 1973–1990
Model Years:	1963–1975 · 1973–1990
Manufacturer:	ZF Friedrichshafen
Class:	3-Speed Automatic Transmission for Longitudinal and Transverse Engines
Successor:	ZF 4HP transmission Family

The 3HP is a 3-speed Automatic transmission family with a hydrodynamic Torque converter with hydraulic control for passenger cars from ZF Friedrichshafen AG. In selector level position "P", the output is locked mechanically. The Ravigneaux planetary gearset types were first introduced in 1963 and produced through the mid seventies. The Simpson planetary gearset types were launched in 1973 and produced through 1990. Both were used in different versions in a large number of cars.

Gear Ratios!!R!1!2!3!Total
Span!Span
Center!Avg.
Step!Compo-
nents

3HP 12 Small Engines								2 Gearsets 3 Brakes 2 Clutches
3HP 12 Big Engines
3HP 22 Big Engines								2 Gearsets 3 Brakes 2 Clutches
3HP 22 Small Engines
3HP 22 Porsche 944

1963: 3HP 12 · Ravigneaux Planetary Gearset Types

Introduction

The 3HP 12 was produced through the mid-seventies and has been used in a variety of cars. There are versions for longitudinal and transverse engines.

With Assessment!colspan=2

Planetary Gearset: Teeth Ravigneaux	Count	Total Center	Avg.
Model Type	Version First Delivery	S1 R1	S2 R2	Brakes Clutches	Ratio Span	Gear Step
Gear Ratio		R {i _{R}}		1 {i _{1}}	2 {i _{2}}	3 {i _{3}}
Step		- \tfrac{i _{R}} {i _{1}}		\tfrac{i _{1}} {i _{1}}	\tfrac{i _{1}} {i _{2}}	\tfrac{i _{2}} {i _{3}}
Δ Step					\tfrac{i _{1}} {i _{2}} : \tfrac{i _{2}} {i _{3}}
Shaft Speed		\tfrac{i _{1}} {i _{R}}		\tfrac{i _{1}} {i _{1}}	\tfrac{i _{1}} {i _{2}}	\tfrac{i _{1}} {i _{3}}
Δ Shaft Speed		0 - \tfrac{i _{1}} {i _{R}}		\tfrac{i _{1}} {i _{1}} - 0	\tfrac{i _{1}} {i _{2}} - \tfrac{i _{1}} {i _{1}}	\tfrac{i _{1}} {i _{3}} - \tfrac{i _{1}} {i _{2}}
3HP 12	160Nm 1963	25 32	32 64	3 2
Gear Ratio				\tfrac{ 64 }{ 25 }		\tfrac{ 1 }{ 1 }
Step				1.0000		1.5200
Δ Step					1.1080
Speed				1.0000	1.6842	2.5600
Δ Speed				1.0000	0.6842	0.8758
3HP 12	Big Engines 1963	28 32	32 64	3 2
Gear Ratio				\tfrac{ 16 }{ 7 }	\tfrac{ 10 } { 7 }	\tfrac{ 1 }{ 1 }
Step				1.0000	1.6000	1.4286
Δ Step					1.1280
Speed				1.0000	1.6000	2.2857
Δ Speed				1.0000	0.6000	0.6842
Ratio		- \tfrac{R _{2}} {S _{2}}		\tfrac{R _{1} R _{2}} {S _{1} S _{2}}	\tfrac{R _{2} (S _{1+} R _{1)}} {S _{1} (S _{2+} R _{2)}}	\tfrac{ 1 } { 1 }
Algebra And Actuated Shift Elements
Brake A					❶
Brake B					❶
Brake C		❶		❶
Clutch D				❶	❶	❶
Clutch E		❶				❶

1973: 3HP 22 · Simpson Planetary Gearset Types

Introduction

The all new 3HP 22 was introduced in 1973 and was produced through 1990 and has been used in a variety of cars from Alfa Romeo, BMW,^[1] Citroën, Peugeot, and Fiat.^[2]

45kg (99lb) with converter

Control	mechanical · hydraulic

With Assessment!colspan=2

Planetary Gearset: Teeth Simpson	Count	Total Center	Avg.
Model Type	Version First Delivery	S1 R1	S2 R2	Brakes Clutches	Ratio Span	Gear Step
Gear Ratio		R {i _{R}}		1 {i _{1}}	2 {i _{2}}	3 {i _{3}}
Step		- \tfrac{i _{R}} {i _{1}}		\tfrac{i _{1}} {i _{1}}	\tfrac{i _{1}} {i _{2}}	\tfrac{i _{2}} {i _{3}}
Δ Step					\tfrac{i _{1}} {i _{2}} : \tfrac{i _{2}} {i _{3}}
Shaft Speed		\tfrac{i _{1}} {i _{R}}		\tfrac{i _{1}} {i _{1}}	\tfrac{i _{1}} {i _{2}}	\tfrac{i _{1}} {i _{3}}
Δ Shaft Speed		0 - \tfrac{i _{1}} {i _{R}}		\tfrac{i _{1}} {i _{1}} - 0	\tfrac{i _{1}} {i _{2}} - \tfrac{i _{1}} {i _{1}}	\tfrac{i _{1}} {i _{3}} - \tfrac{i _{1}} {i _{2}}
3HP 22	320Nm 1963	35 73	35 73	3 2
Gear Ratio				\tfrac{ 181 } { 73 }		\tfrac{ 1 } { 1 }
Step				1.0000		1.4795
Δ Step					1.1328
Speed				1.0000	1.6759	2.4795
Δ Speed				1.0000	0.6759	0.8035
3HP 22	Small Engines 1973	35 73	41 73	3 2
Gear Ratio				\tfrac{ 6983 }{ 2555 }		\tfrac{ 1 }{ 1 }
Step				1.0000		1.5616
Δ Step					1.1207
Speed				1.0000	1.7501	2.7331
Δ Speed				1.0000	0.7501	0.9829
3HP 22	Porsche 944 1981	28 68	32 64	3 2
Gear Ratio				\tfrac{ 19 }{ 7 }		\tfrac{ 1 }{ 1 }
Step				1.0000		1.5000
Δ Step					1.2063
Speed				1.0000	1.8095	2.7143
Δ Speed				1.0000	0.8095	0.9048
Ratio		- \tfrac{R _{1}} {S _{1}}	\tfrac{S _{1} (S _{2+} R _{2)+} R _{1} S _{2}} {S _{1} R _{2}}		\tfrac{S _{2+} R _{2}} {R _{2}}	\tfrac{ 1 } { 1 }
Algebra And Actuated Shift Elements
Brake A					❶
Brake B					❶	❶
Brake C		❶		❶
Clutch D				❶	❶	❶
Clutch E		❶				❶

See also

• list of ZF transmissions

Notes and References

1. Web site: BMWE21.net. BMWe21.net. 24 November 2013.
2. Web site: ZF North America application chart (automatic). ZF.com. 22 November 2013.