ZF 9HP transmission

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9HPis thetrademarkname for theZF Friedrichshafen9-speedautomatic transmissionmodels (9-speed transmission withHydraulic converter andPlanetary gearsets) fortransverse engineapplications, designed by ZF's subsidiary inSaarbrückenand built inGray Court, South Carolina.[1]It is used infront-wheel driveandall-wheel drivevehicles.

ZF 9HP
Overview
ManufacturerZF Friedrichshafen
Production2013–present
AssemblyGray Court, South Carolina,United States
Body and chassis
Class9-speedtransverseautomatic transmission
RelatedAisin-Toyota 8-speed·ZF 8HP
Chronology
PredecessorZF 4HP

The 9HP is the world's first 9-speed automatic transmission for passenger cars.Land RoverandJeeplaunched it at the 2013Geneva Motor Show.[2]The2014 Jeep Cherokeethen was the first car with this transmission delivered to customers.

Gear Ratios[a]
Gear
Model
R 1 2 3 4 5 6 7 8 9 Total
Span
Span
Center
Avg.
Step
Compo-
nents
9HP 48 · 2013
9HP 28 · 2013
−3.805 4.700 2.842 1.909 1.382 1.000 0.808 0.699 0.580 0.479 9.808 1.501 1.330 4 Gearsets
3 Brakes
3 Clutches
  1. ^Differences in gear ratios have a measurable, direct impact on vehicle dynamics, performance, waste emissions as well as fuel mileage

Specifications

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Basic Concept

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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 patenteddog clutches,[3]which replace bulkier conventional clutch packs, and a nested gear set.[2]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 207lb⋅ft(280N⋅m) and 354lb⋅ft(480N⋅m).[1]

Gear Ratios
With Assessment Planetary Gearset: Teeth[a] Count Total[b]
Center[c]
Avg.[d]
Model
Type
Version
First Delivery · Weight
S4[e]
R4[f]
S3[g]
R3[h]
S2[i]
R2[j]
S1[k]
R1[l]
Brakes
Clutches
Ratio
Span
Gear
Step[m]
Gear
Ratio
R
1
2
3
4
5
6
7
8
9
Step[m] [n] [o]
Δ Step[p][q]
Shaft
Speed
Δ Shaft
Speed[r]
9HP 28
9HP 48
280 Nm[s]· 2013 · 78kg(172lb)
480 Nm[t]· 2013 · 86kg(190lb)
42
110
42
110
91
133
42
86
3[u]
3[v]
9.8085
1.5007
1.3303[m]
Gear
Ratio
−3.8049[n]
4.7001
2.8419
1.9094
1.3818[q]
1.0000
0.8081[r]
0.6995[q][r]
0.5802[q]
0.4792
Step 0.8095[n] 1.0000 1.6538 1.4884 1.3818 1.3818 1.2375 1.1553 1.2056 1.2107
Δ Step[p] 1.1112 1.0771 1.0000[q] 1.1167 1.0711 0.9583[q] 0.9958[q]
Speed -1.2353 1.0000 1.6538 2.4615 3.4014 4.7001 5.5816 6.7197 8.1015 9.8085
Δ Speed 1.2353 1.0000 0.6538 0.8077 0.9399 1.2987 1.1161[r] 0.9035[r] 1.3818 1.7066
Ratio
R & Even
Ratio
Odd
Algebra And Actuated Shift Elements[w]
Brake A[x]
Brake C[y]
Brake D[z]
Clutch B[aa]
Clutch E[ab]
Clutch F[ac]
  1. ^Layout
    • Input and output are on the same side
    • Planetary gearset 4 is on the input (turbine) side
    • Input shafts are, if actuated,S1,R1+ S3,andC3(planetary gear carrier of gearset 1) + R4
    • Output shaft isC4(planetary gear carrier of gearset 4)
  2. ^Total Ratio Span (Total Ratio Spread · Total Gear Ratio)
    • A wider span enables the
      • downspeeding when driving outside the city limits
      • increase the climbing ability
        • when driving over mountain passes or off-road
        • or when towing a trailer
  3. ^Ratio Span's Center
    • The center indicates the speed level of the transmission
    • Together with the final drive ratio
    • it gives the shaft speed level of the vehicle
  4. ^Average Gear Step
    • With decreasing step width
      • the gears connect better to each other
      • shifting comfort increases
  5. ^Sun 4: sun gear of gearset 4
  6. ^Ring 4: ring gear of gearset 4
  7. ^Sun 3: sun gear of gearset 3
  8. ^Ring 3: ring gear of gearset 3
  9. ^Sun 2: sun gear of gearset 2
  10. ^Ring 2: ring gear of gearset 2
  11. ^Sun 1: sun gear of gearset 1
  12. ^Ring 1: ring gear of gearset 1
  13. ^abcStandard 50:50
    — 50 % Is Above And 50 % Is Below The Average Gear Step —
    • With steadily decreasing gear steps (yellow highlighted lineStep)
    • and a particularly large step from 1st to 2nd gear
      • thelower half of the gear steps(between the small gears; rounded down, here the first 4)is always larger
      • and theupper half of the gear steps(between the large gears; rounded up, here the last 4)is always smaller
    • than the average gear step(cell highlighted yellow two rows above on the far right)
    • lower half:smaller gear steps are a waste of possible ratios (red bold)
    • upper half:larger gear steps are unsatisfactory (red bold)
  14. ^abcStandard R:1
    — Reverse And 1st Gear Have The Same Ratio —
    • The ideal reverse gear has the same transmission ratio as 1st gear
      • no impairment when maneuvering
      • especially when towing a trailer
      • a torque converter can only partially compensate for this deficiency
    • Plus 11.11 % minus 10 % compared to 1st gear is good
    • Plus 25 % minus 20 % is acceptable (red)
    • Above this is unsatisfactory (bold)
  15. ^Standard 1:2
    — Gear Step 1st To 2nd Gear As Small As Possible —
    • With continuously decreasing gear steps (yellow marked lineStep)
    • thelargest gear step is the one from 1st to 2nd gear,which
      • for a good speed connection and
      • a smooth gear shift
    • must be as small as possible
      • A gear ratio of up to 1.6667:1 (5:3) is good
      • Up to 1.7500:1 (7:4) is acceptable (red)
      • Above is unsatisfactory (bold)
  16. ^abFrom large to small gears (from right to left)
  17. ^abcdefgStandard STEP
    — From Large To Small Gears: Steady And Progressive Increase In Gear Steps —
    • Gear steps should
      • increase:Δ Step (first green highlighted lineΔ Step) is always greater than 1
      • Asprogressiveas possible: Δ Step is always greater than the previous step
    • Not progressively increasing is acceptable (red)
    • Not increasing is unsatisfactory (bold)
  18. ^abcdeStandard SPEED
    — From Small To Large Gears: Steady Increase In Shaft Speed Difference —
    • Shaft speed differences should
      • increase:Δ Shaft Speed (second line marked in greenΔ (Shaft) Speed) is always greater than the previous one
    • 1 difference smaller than the previous one is acceptable (red)
    • 2 consecutive ones are a waste of possible ratios (bold)
  19. ^280N⋅m(207lb⋅ft) for both gasoline and diesel[1]
  20. ^450N⋅m(332lb⋅ft) for gasoline
    480N⋅m(354lb⋅ft) for diesel[1]
  21. ^Thereof 1 dog break[3]
  22. ^Thereof 1 dog clutch[3]
  23. ^Permanentlycoupled elements
    • C1,C2,andR3
    • S3andS4
    • C3andR4
  24. ^Dog brake blocksS3andS4
  25. ^BlocksS1
  26. ^BlocksR2
  27. ^CouplesS1with input shaft
  28. ^CouplesC3(carrier 3) andR4with input shaft
  29. ^Dog clutch couplesR1andS2with input shaft

How It Works

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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 ordinateC4(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

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Concentric Planetary gearset-Simpson Planetary gearset

▶️ Interactive Nomogram

This interactivenomogramis a real geometric calculator exactly representing the rotational speeds of the transmission's3x4 = 12internal shafts for each of its9ratios (+reverse), grouped according to their5 permanentcoupling on4 jointordinates and3 independentordinates. These ordinates are positioned on theabscissain strict accordance with the proportions of the sun gears' teeth numbers relative to those of their rings. Consequently, theoutputratios on the6th ordinate(carrier of the fourth planetary gearset) follows closely those of the actual transmission. This advantageous geometric construction sets us free fromRobert Willis' famous and tedious formula,[4]because all calculations are exclusively determined by lengths ratios, respectively teeth numbers on theabscissafor the 4 epicyclic ratios, and of rotational speeds on the6th ordinatefor the 10 gear ratios.

Legend

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A:Dog brake (blocksS3andS4)
C:Brake (blocksS1)
D:Brake (blocksR2)
B:Clutch (couplesS1with input shaft)
E:Clutch (couplesC3(carrier 3) andR4with input shaft)
F:Dog clutch (couplesR1andS2with input shaft)

Applications

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Acura

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

Alfa Romeo

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Chrysler

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Dodge

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FIAT

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Opel/Vauxhall

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Honda

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Infiniti

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Jeep

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Ram Trucks

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Land Rover

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Jaguar

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Nissan

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Technical imperfections

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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.[8]

Chrysler issued Technical Service Bulletins (TSB) for the 2014Jeep Cherokeeto "fix rough and delayed gearshifts", and Acura has issued transmission-related recalls for the 2015Acura TLX.[9][10]

Production

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Production of the 9HP started in 2013 at ZF's Gray Court facility inLaurens, South Carolina.400,000 units are produced per year.[11]

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.[12]

See also

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References

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  1. ^abcd"ZF Develops 9-Speed Automatic Transmission for Passenger Cars".
  2. ^abc"Land Rover uses the 9-speed automatic transmission by ZF".
  3. ^abcZF’s 9-Speed 9HP Transmission Puts Dog Clutches On The Leash
  4. ^Robert Willis (1841)."Principles of mechanism"(PDF).Retrieved2024-11-04.
  5. ^"HONDA British-built CR-V refreshed for 2015".
  6. ^"World Premiere in Geneva: Land Rover installs the world's first 9-speed automatic passenger car transmission from ZF".
  7. ^"2022 Nissan Pathfinder Adds New Features and Ditches the CVT".4 February 2021.
  8. ^"Holy Shift ZF 9 Speed Automatic Problems Mount Chrysler Releases Third Software Update for Jeep Cherokee".4 February 2015.
  9. ^"Short Shirt Jeep Cherokee 9 Speed Automatic Gets Second Update for Rough Shifting".
  10. ^"Acura TLX Shifting Problems".
  11. ^"Spotted: ZF testing the 9HP Hybrid transmission".
  12. ^Chrysler Group Dedicates New Plant and Launches Nine-Speed Production in Tipton, Ind.