ZF 9HP transmission

9HP is the trademark name for the ZF Friedrichshafen 9-speed automatic transmission models (9-speed transmission with Hydraulic converter and Planetary gearsets) for transverse engine applications, designed by ZF's subsidiary in Saarbrücken and built in Gray Court, South Carolina. It is used in front-wheel drive and all-wheel drive vehicles.

The 9HP is the world's first 9-speed automatic transmission for passenger cars. Land Rover and Jeep launched it at the 2013 Geneva Motor Show. The 2014 Jeep Cherokee then was the first car with this transmission delivered to customers.

Gear RatiosTemplate:Efn

Template:Diagonal split header	R	1	2	3	4	5	6	7	8	9	Total Span	Span Center	Avg. Step	Compo- nents
9HP 48 · 2013 9HP 28 · 2013	Template:Round	Template:Round	Template:Round	Template:Round	Template:Round	Template:Round	Template:Round	Template:Round	Template:Round	Template:Round	Template:Round	Template:Round	Template:Round	4 Gearsets 3 Brakes 3 Clutches

Specifications

Basic Concept

The 9HP is only 0.24 inches (6 mm) longer than, and weighs 16.5 lbs (7.5 kg) less than, the outgoing six-speed transmission. The compact packaging is achieved by using a number of innovative design features: a new compact hydraulic vane-type pump, two patented dog clutches, which replace bulkier conventional clutch packs, and a nested gear set. ZF claims that it is able to save an average of 16% in fuel compared with current 6-speed automatic transmissions. The gear ratio spread is 9.81:1. The transmission has a torque range between Template:Convert and Template:Convert.

Gear Ratios

With Assessment				Planetary Gearset: TeethTemplate:Efn				Count	TotalTemplate:Efn CenterTemplate:Efn	Avg.Template:Efn
Model Type	Version First Delivery · Weight			S4Template:Efn R4Template:Efn	S3Template:Efn R3Template:Efn	S2Template:Efn R2Template:Efn	S1Template:Efn R1Template:Efn	Brakes Clutches	Ratio Span	Gear StepTemplate:Efn
Gear Ratio	R $i_R$	1 $i_1$	2 $i_2$	3 $i_3$	4 $i_4$	5 $i_5$	6 $i_6$	7 $i_7$	8 $i_8$	9 $i_9$
StepTemplate:Efn	$-\frac{i_R}{i_1}$Template:Efn	$\frac{i_1}{i_1}$	$\frac{i_1}{i_2}$Template:Efn	$\frac{i_2}{i_3}$	$\frac{i_3}{i_4}$	$\frac{i_4}{i_5}$	$\frac{i_5}{i_6}$	$\frac{i_6}{i_7}$	$\frac{i_7}{i_8}$	$\frac{i_8}{i_9}$
Δ StepTemplate:EfnTemplate:Efn			$\frac{i_1}{i_2}:\frac{i_2}{i_3}$	$\frac{i_2}{i_3}:\frac{i_3}{i_4}$	$\frac{i_3}{i_4}:\frac{i_4}{i_5}$	$\frac{i_4}{i_5}:\frac{i_5}{i_6}$	$\frac{i_5}{i_6}:\frac{i_6}{i_7}$	$\frac{i_6}{i_7}:\frac{i_7}{i_8}$	$\frac{i_7}{i_8}:\frac{i_8}{i_9}$
Shaft Speed	$\frac{i_1}{i_R}$	$\frac{i_1}{i_1}$	$\frac{i_1}{i_2}$	$\frac{i_1}{i_3}$	$\frac{i_1}{i_4}$	$\frac{i_1}{i_5}$	$\frac{i_1}{i_6}$	$\frac{i_1}{i_7}$	$\frac{i_1}{i_8}$	$\frac{i_1}{i_9}$
Δ Shaft SpeedTemplate:Efn	$0-\frac{i_1}{i_R}$	$\frac{i_1}{i_1}-0$	$\frac{i_1}{i_2}-\frac{i_1}{i_1}$	$\frac{i_1}{i_3}-\frac{i_1}{i_2}$	$\frac{i_1}{i_4}-\frac{i_1}{i_3}$	$\frac{i_1}{i_5}-\frac{i_1}{i_4}$	$\frac{i_1}{i_6}-\frac{i_1}{i_5}$	$\frac{i_1}{i_7}-\frac{i_1}{i_6}$	$\frac{i_1}{i_8}-\frac{i_1}{i_7}$	$\frac{i_1}{i_9}-\frac{i_1}{i_8}$
Torque RatioTemplate:Efn	$\frac{T_{2;R}}{T_{1;R}}$	$\frac{T_{2;1}}{T_{1;1}}$	$\frac{T_{2;2}}{T_{1;2}}$	$\frac{T_{2;3}}{T_{1;3}}$	$\frac{T_{2;4}}{T_{1;4}}$	$\frac{T_{2;5}}{T_{1;5}}$	$\frac{T_{2;6}}{T_{1;6}}$	$\frac{T_{2;7}}{T_{1;7}}$	$\frac{T_{2;8}}{T_{1;8}}$	$\frac{T_{2;9}}{T_{1;9}}$
EfficiencyTemplate:Efn	ηR	η1	η2	η3	η4	η5	η6	η7	η8	η9
9HP 28 9HP 48	280 NmTemplate:Efn · 2013 · Template:Convert 480 NmTemplate:Efn · 2013 · Template:Convert			42 110	42 110	91 133	42 86	3Template:Efn 3Template:Efn	Template:Round Template:Round	Template:RoundTemplate:Efn
Gear Ratio	Template:Font color	Template:Round $\frac{184,832}{39,325}$	Template:Round $\frac{369,664}{130,075}$	Template:Round $\frac{5,776}{3,025}$	Template:Font color	Template:Round $\frac{1}{1}$	Template:Font color	Template:Font colorTemplate:EfnTemplate:Efn $\frac{6,272}{8,967}$	Template:Font colorTemplate:Efn $\frac{76}{131}$	Template:Round $\frac{2,176}{4,541}$
Step	Template:Font color	1.0000	1.6538	1.4884	Template:Font color	1.3818	1.2375	Template:Font color	Template:Font color	1.2107
Δ StepTemplate:Efn			1.1112	1.0771	Template:Font colorTemplate:Efn	1.1167	1.0711	Template:Font colorTemplate:Efn	Template:Font colorTemplate:Efn
Speed	Template:Font color	1.0000	1.6538	2.4615	3.4014	4.7001	Template:Font color	Template:Font color	8.1015	9.8085
Δ Speed	Template:Font color	1.0000	0.6538	0.8077	0.9399	1.2987	Template:Font colorTemplate:Efn	Template:Font colorTemplate:Efn	1.3818	1.7066
TorqueTemplate:Efn	–3.4099	4.5402	2.7675	1.8779	1.3704	1.0000	0.7966	0.6857	0.5673	0.4582
EfficiencyTemplate:Efn	0.8962	0.9660	0.9738	0.9835	0.9917	1.0000	0.9857	0.9803	0.9779	0.9561
Ratio R & Even	$\frac{(S_1{S}_2-R_1{R}_2)(S_3+R_3)(S_4+R_4)}{S_1{S}_2{R}_3{R}_4}$		$\frac{(S_1+R_1)(S_3+R_3)(S_4+R_4)}{R_1{R}_3{R}_4}$		$\frac{S_4+R_4}{R_4}$	$\frac{S_3(S_1+R_1)(S_4+R_4)}{S_3(S_1+R_1)(S_4+R_4)+S_1{R}_3{S}_4}$		$i_8=\frac{S_3(S_4+R_4)}{S_4(S_3+R_3)+S_3{R}_4}$
Ratio Odd	$\frac{(S_2+R_2)(S_3+R_3)(S_4+R_4)}{S_2{R}_3{R}_4}$		$i_3=\frac{(S_3+R_3)(S_4+R_4)}{R_3{R}_4}$		$i_5=\frac{1}{1}$	$\frac{S_3(S_2+R_2)(S_4+R_4)}{S_3(S_2+R_2)(S_4+R_4)+R_2{R}_3{S}_4}$		$\frac{S_3(R_1{R}_2-S_1{S}_2)(S4+R_4)}{S_3(R_1{R}_2-S_1{S}_2)(S_4+R_4)+R_1{R}_2{R}_3{S}_4}$
Algebra And Actuated Shift ElementsTemplate:Efn
Brake ATemplate:Efn	❶	❶	❶	❶	❶
Brake CTemplate:Efn			❶				❶		❶
Brake DTemplate:Efn	❶	❶						❶	❶	❶
Clutch BTemplate:Efn	❶			❶		❶				❶
Clutch ETemplate:Efn					❶	❶	❶	❶	❶	❶
Clutch FTemplate:Efn		❶	❶	❶	❶	❶	❶	❶
Template:Notelist

How It Works

An Animated Drive Line Schematic & A Rotational Speeds Nomogram

These ordinates are positioned on the abscissa in strict accordance with the proportions of the sun gears' teeth numbers relative to those of their rings. Consequently, the output ratios on the ordinate C₄ (carrier of planetary gearset 4) follows closely to those of the actual transmission. Note that elements A and F are labelled swapped (cf. legend below).

Nomogram

Template:Center

▶️ Interactive Nomogram

This interactive nomogram is a real geometric calculator exactly representing the rotational speeds of the transmission's 3x4 = 12 internal shafts for each of its 9 ratios (+ reverse), grouped according to their 5 permanent coupling on 4 joint ordinates and 3 independent ordinates. These ordinates are positioned on the abscissa in strict accordance with the proportions of the sun gears' teeth numbers relative to those of their rings. Consequently, the output ratios on the 6th ordinate (carrier of the fourth planetary gearset) follows closely those of the actual transmission. This advantageous geometric construction sets us free from Robert Willis' famous and tedious formula, because all calculations are exclusively determined by lengths ratios, respectively teeth numbers on the abscissa for the 4 epicyclic ratios, and of rotational speeds on the 6th ordinate for the 10 gear ratios.

Legend

A: Dog brake (blocks S₃ and S₄)
C: Brake (blocks S₁)
D: Brake (blocks R₂)
B: Clutch (couples S₁ with input shaft)
E: Clutch (couples C₃ (carrier 3) and R₄ with input shaft)
F: Dog clutch (couples R₁ and S₂ with input shaft)

Applications

Acura

• TLX (2015–2020, V6 models)
• MDX (2016–2020, non-hybrid models)

Alfa Romeo

• Tonale 2.0L turbo engine

Chrysler

• 200
• Pacifica minivan (petrol engine)
• Voyager

Dodge

• Hornet (2023–, 2.0L turbo engine)
• Rampage

FIAT

• Dobló/RAM Promaster City (2015–2022)
• 500C
• Toro
• Ducato (2020–)

MG

• MG 7 (2023–)

Opel/Vauxhall

• Astra (2020, diesel engine)
• Insignia (2020, diesel engine)

Honda

• CR-V (2015–2022, diesel engine)
• Pilot (2016–2020 optional, 2021–2022 standard on all trims)
• Avancier/UR-V (2016–, 2.0L turbo engine)
• Odyssey (2018–2019 standard, 10-speed automatic optional)
• Passport (2019–2025)
• Ridgeline (2020–)
• Civic (2018–2022, diesel engine)

Infiniti

• QX60 (2022–)

Jeep

• Cherokee (KL)
• Renegade
• Compass (MP)
• Gran Commander

Ram Trucks

• ProMaster City
• ProMaster (2022–)

Land Rover

• Range Rover Evoque
• Discovery Sport

Jaguar

• E-Pace

Nissan

• Pathfinder (2022–)

Technical imperfections

The transmission has been problematic, as customers of Jeep, Chrysler, and Acura models equipped with the transmission have experienced problems in their vehicles regarding slow shifting and noisy operation. ZF has said this is due to software problems, not mechanical issues.

Chrysler issued Technical Service Bulletins (TSB) for the 2014 Jeep Cherokee to "fix rough and delayed gearshifts", and Acura has issued transmission-related recalls for the 2015 Acura TLX.

Production

Production of the 9HP started in 2013 at ZF's Gray Court facility in Laurens, South Carolina. 400,000 units are produced per year.

Production of the 9HP for Fiat and Chrysler vehicles began in May 2013 at Indiana Transmission Plant I (ITPI), followed by Tipton Transmission Plant in Tipton County, Indiana in May 2014.

See also

• List of Chrysler transmissions
• List of ZF transmissions