The 3HP 22 is a three-speed automatic transmission from ZF Friedrichshafen AG for passenger cars. Introduced in 1973, it was produced through 1990, and has been used in a variety of cars from Alfa Romeo, BMW,^[1] Citroën, Peugeot, and Fiat.^[2]

Specifications

Technical data

Gear Teeth and Ratios		PlanetaryGearset Teeth[lower-alpha 1] Simpson		Count	Total	Avg.
Model Type	First Delivery	${\displaystyle S_{1}}$[lower-alpha 2] ${\displaystyle R_{1}}$[lower-alpha 3]	${\displaystyle S_{2}}$[lower-alpha 4] ${\displaystyle R_{2}}$[lower-alpha 5]	Brakes Clutches	Ratio Span	Gear Step
Gear		R		1	2	3
Step ${\displaystyle i_{n-1}/i_{n}}$		–R : 1			1 : 2	2 : 3
3HP 22 A · Big Engines	1973	35 73	35 73	3 2	2.4795	1.5746
Ratio ${\displaystyle i_{n}}$		−2.0857 ${\displaystyle -{\tfrac {73}{35}}}$		2.4795 ${\displaystyle {\tfrac {181}{73}}}$	1.4795 ${\displaystyle {\tfrac {108}{73}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$
Step		0.8412			1.6759	1.4795
3HP 22 B · Small Engines	1973	35 73	41 73	3 2	2.7331	1.6532
Ratio ${\displaystyle i_{n}}$		−2.0857 ${\displaystyle -{\tfrac {73}{35}}}$		2.7331 ${\displaystyle {\tfrac {6,983}{2,555}}}$	1.5616 ${\displaystyle {\tfrac {114}{73}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$
Step		0.7631			1.7501	1.5616
3HP 22 Porsche 944	1981	28 68	32 64	3 2	2.7143	1.6475
Ratio ${\displaystyle i_{n}}$		−2.4286 ${\displaystyle -{\tfrac {17}{7}}}$		2.7143 ${\displaystyle {\tfrac {19}{7}}}$	1.5000 ${\displaystyle {\tfrac {3}{2}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$
Step		0.8947			1.8095	1.5000
Ratio		${\displaystyle -{\tfrac {R_{1}}{S_{1}}}}$	${\displaystyle {\tfrac {S_{1}(S_{2}+R_{2})+R_{1}S_{2}}{S_{1}R_{2}}}}$		${\displaystyle {\tfrac {S_{2}+R_{2}}{R_{2}}}}$	${\displaystyle {\tfrac {1}{1}}}$

1. ↑ Planetary gearset orientation: (1) Planetary gearset 1 is on the input (turbine) side (2) Output shaft is ring 1 (ring gear of gearset 1)
2. ↑ Sun gear of gearset 1
3. ↑ Ring gear of gearset 1
4. ↑ Sun gear of gearset 2
5. ↑ Ring gear of gearset 2

See also

• list of ZF transmissions

References