ZF 8HP
Automatic Transmission 8HP70
Overview
Manufacturer	ZF Friedrichshafen
Production	2008–present
Body and chassis
Class	8-speed automatic transmission
Related	GM 8L transmission
Chronology
Predecessor	ZF 6HP transmission

The ZF 8HP transmission is ZF Friedrichshafen AG's trademark name for its 8-speed automatic transmission models for longitudinal engine applications. The name is short for 8-speed transmission with hydraulic converter and planetary gearsets. Designed and first built by ZF's subsidiary in Saarbrücken, Germany, it debuted in 2008 on the BMW 7 Series (F01) 760Li sedan fitted with the V12 engine. BMW remains a major customer for the transmission.

Another major customer is Stellantis, who both received a license to produce the transmission and set up a joint-venture plant with ZF. Stellantis has built the transmission at its Kokomo Transmission plant since 2013 under their own brand name, the Torqueflite 8.^[1][2] The joint venture plant in Gray Court, South Carolina opened in 2017.^[3]

Specifications

Design

One of the main aims of the ZF 8HP transmission is to improve vehicle fuel economy with extra speeds. Compared to the six-speed ZF 6HP transmission it uses 12% less fuel, and 14% less than a 5-speed transmission.^[4][5] Due to changes in internal design, the shift times have reduced to 200 milliseconds; additionally, the unit brings the ability to shift in a non-sequential manner – going from gear 8 to gear 2 in extreme situations.^[6] In the 8HP70 version, it has a torque handling limit of 700 N⋅m (520 lbf⋅ft), and weighs 87 kg (192 lb).^[7]

First generation 8HP products were released starting in 2010. In addition to the rear-wheel drive variant, two different four-wheel drive versions were available, with a version destined for Volkswagen Group applications using a Torsen centre differential.^[8] It is able to encompass a torque range from 300 N⋅m (220 lbf⋅ft) to 1,000 N⋅m (740 lbf⋅ft), and is available for use in middle-class cars through to large luxury sport utility vehicles.^[8]

Second generation 8HP products were released starting in 2014. Efficiency improvements over the original design and the first generation include a wider ratio spread of 7.8:1, reduced drag torque from the shift elements, reduction in required oil pump pressure, and broadened use of the coasting and start-stop systems.^[9] ZF estimated fuel economy improvement over first generation 8HP kits to be 3%. Refinements were also made with respect to vibration.

Third generation 8HP products were released starting in 2018. Major improvements are total spread of 8.6 and a fuel economy improvement of 2.5% compared to the second generation. There are several options in maximum torque available, also the gearbox is available with mild hybrid and plug in hybrid options: With 15 kW and 200 Nm supporting boosting and recuperation in combination with 48 Volt technology up to 90 kW and 250 NM for usage with higher voltage.^[10]

Technical data

Gear teeth and ratios[a]			Planetary Gearset: Teeth[b]				Count	Total	Avg.
Model	Version First delivery		${\displaystyle {S_{1}}}$[c] ${\displaystyle {R_{1}}}$[d]	${\displaystyle {S_{2}}}$[e] ${\displaystyle {R_{2}}}$[f]	${\displaystyle {S_{3}}}$[g] ${\displaystyle {R_{3}}}$[h]	${\displaystyle {S_{4}}}$[i] ${\displaystyle {R_{4}}}$[j]	Brakes Clutches	Ratio span	Gear step
Gear ${\displaystyle n}$	R	1	2	3	4	5	6	7	8
Step ${\displaystyle i_{n-1}/i_{n}}$	–R : 1		1 : 2	2 : 3	3 : 4	4 : 5	5 : 6	6 : 7	7 : 8
8HP 70[k]	700 N⋅m (516 lb⋅ft) · 2008		48[11] 96	48[11] 96	69[12] 111	23[12] 85	2 3	7.0435	1.3216
Ratio ${\displaystyle i_{n}}$	−3.2968 ${\displaystyle -{\tfrac {1,744}{529}}}$	4.6957 ${\displaystyle {\tfrac {108}{23}}}$	3.1304 ${\displaystyle {\tfrac {72}{23}}}$	2.1039 ${\displaystyle {\tfrac {162}{77}}}$	1.6667 ${\displaystyle {\tfrac {5}{3}}}$	1.2845 ${\displaystyle {\tfrac {8,826}{6,871}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8392 ${\displaystyle {\tfrac {120}{143}}}$	0.6667 ${\displaystyle {\tfrac {2}{3}}}$
Step	0.7021		1.5000	1.4879	1.2623	1.2975	1.2845	1.1917	1.2587
1st Generation
8HP 30/I 8HP 45	300 N⋅m (221 lb⋅ft) · 2010 450 N⋅m (332 lb⋅ft) · 2010		48 96	48 96	60 96	28 104	2 3	7.0714	1.3224
Ratio ${\displaystyle i_{n}}$	−3.2952 ${\displaystyle -{\tfrac {346}{105}}}$	4.7143 ${\displaystyle {\tfrac {33}{7}}}$	3.1429 ${\displaystyle {\tfrac {22}{7}}}$	2.1064 ${\displaystyle {\tfrac {99}{47}}}$	1.6667 ${\displaystyle {\tfrac {5}{3}}}$	1.2854 ${\displaystyle {\tfrac {1,171}{911}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8387 ${\displaystyle {\tfrac {26}{31}}}$	0.6667 ${\displaystyle {\tfrac {2}{3}}}$
Step	0.6990		1.5000	1.4921	1.2638	1.2966	1.2854	1.1923	1.2581
8HP 55 8HP 65 8HP 70 8HP 90	650 N⋅m (479 lb⋅ft) · 2010 650 N⋅m (479 lb⋅ft) · 2010 700 N⋅m (516 lb⋅ft) · 2010 900 N⋅m (664 lb⋅ft) · 2010		48 [11][13] 96	48 [11][13] 96	69 111	28 104	2 3	7.0714	1.3224
Ratio ${\displaystyle i_{n}}$	−3.3168 ${\displaystyle -{\tfrac {534}{161}}}$	4.7143 ${\displaystyle {\tfrac {33}{7}}}$	3.1429 ${\displaystyle {\tfrac {22}{7}}}$	2.1064 ${\displaystyle {\tfrac {99}{47}}}$	1.6667 ${\displaystyle {\tfrac {5}{3}}}$	1.2847 ${\displaystyle {\tfrac {5,397}{4,201}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8392 ${\displaystyle {\tfrac {120}{143}}}$	0.6667 ${\displaystyle {\tfrac {2}{3}}}$
Step	0.7036		1.5000	1.4921	1.2638	1.2973	1.2847	1.1917	1.2587
2nd Generation
8HP 75/I[14]	740 N⋅m (546 lb⋅ft) · 2014		48 96	48 96	69 111	28 104	2 3	7.0714	1.3224
Ratio	−3.3168	4.7143	3.1429	2.1064	1.6667	1.2847	1.0000	0.8392	0.6667
Step	0.7036		1.5000	1.4921	1.2638	1.2973	1.2847	1.1917	1.2588
8HP 30/II[14] 8HP 50[14]	300 N⋅m (221 lb⋅ft) · 2014 500 N⋅m (369 lb⋅ft) · 2014		48 96	54 96	60 96	24 96	2 3	7.8125	1.3413
Ratio ${\displaystyle i_{n}}$	−3.4560 ${\displaystyle -{\tfrac {432}{125}}}$	5.0000 ${\displaystyle {\tfrac {5}{1}}}$	3.2000 ${\displaystyle {\tfrac {16}{5}}}$	2.1429 ${\displaystyle {\tfrac {15}{7}}}$	1.7200 ${\displaystyle {\tfrac {43}{25}}}$	1.3139 ${\displaystyle {\tfrac {1,507}{1,147}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8221 ${\displaystyle {\tfrac {208}{253}}}$	0.6400 ${\displaystyle {\tfrac {16}{25}}}$
Step	0.6912		1.5625	1.4933	1.2458	1.3091	1.3139	1.2163	1.2846
8HP 75/II[14] 8HP 95[l]	740 N⋅m (546 lb⋅ft) · 2014 900 N⋅m (664 lb⋅ft) · 2014		48 96	54 96	69 111	24 96	2 3	7.8125	1.3413
Ratio ${\displaystyle i_{n}}$	−3.4783 ${\displaystyle -{\tfrac {80}{23}}}$	5.0000 ${\displaystyle {\tfrac {5}{1}}}$	3.2000 ${\displaystyle {\tfrac {16}{5}}}$	2.1429 ${\displaystyle {\tfrac {15}{7}}}$	1.7200 ${\displaystyle {\tfrac {43}{25}}}$	1.3131 ${\displaystyle {\tfrac {2,315}{1,763}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8226 ${\displaystyle {\tfrac {320}{389}}}$	0.6400 ${\displaystyle {\tfrac {16}{25}}}$
Step	0.6956		1.5625	1.4933	1.2458	1.3098	1.3131	1.2156	1.2853
3rd Generation
8HP 76/I[m]	760 N⋅m (561 lb⋅ft) · 2018		48 96	54 96	69 111	24 96	2 3	7.8125	1.3413
Ratio	−3.4783	5.0000	3.2000	2.1429	1.7200	1.3131	1.0000	0.8226	0.6400
Step	0.6956		1.5625	1.4933	1.2458	1.3098	1.3131	1.2156	1.2853
8HP 30/III[n] 8HP 51[o]	300 N⋅m (221 lb⋅ft) · 2018 500 N⋅m (369 lb⋅ft) · 2018		48 96	54 96	60 96	24 102	2 3	8.2031	1.3507
Ratio ${\displaystyle i_{n}}$	−3.7120 ${\displaystyle -{\tfrac {464}{125}}}$	5.2500 ${\displaystyle {\tfrac {21}{4}}}$	3.3600 ${\displaystyle {\tfrac {84}{25}}}$	2.1724 ${\displaystyle {\tfrac {63}{29}}}$	1.7200 ${\displaystyle {\tfrac {43}{25}}}$	1.3161 ${\displaystyle {\tfrac {6,371}{4,841}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8221 ${\displaystyle {\tfrac {208}{253}}}$	0.6400 ${\displaystyle {\tfrac {16}{25}}}$
Step	0.7070		1.5625	1.5467	1.2630	1.3069	1.3161	1.2163	1.2846
8HP 76/II[p] 8HP 80[q]	760 N⋅m (561 lb⋅ft) · 2018 800 N⋅m (590 lb⋅ft) · 2018		48 96	54 96	69 111	24 108	2 3	8.5938	1.3597
Ratio ${\displaystyle i_{n}}$	−3.9930 ${\displaystyle -{\tfrac {2,296}{575}}}$	5.5000 ${\displaystyle {\tfrac {11}{2}}}$	3.5200 ${\displaystyle {\tfrac {88}{25}}}$	2.2000 ${\displaystyle {\tfrac {11}{5}}}$	1.7200 ${\displaystyle {\tfrac {43}{25}}}$	1.3172 ${\displaystyle {\tfrac {191}{145}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8226 ${\displaystyle {\tfrac {320}{389}}}$	0.6400 ${\displaystyle {\tfrac {16}{25}}}$
Step	0.7260		1.5625	1.6000	1.2791	1.3058	1.3172	1.2156	1.2853
Racing Cars
8P 45R[r]	450 N⋅m (332 lb⋅ft) · 2016 up to 1,050 N⋅m (774 lb⋅ft)[20]		TBD	TBD	60 96	TBD	2 3	4.2000	1.2275
Ratio	TBD	TBD	TBD	TBD	TBD	TBD	1.0000	TBD	TBD
Step	TBD		TBD	TBD	TBD	TBD	TBD	TBD	TBD
Commercial Vehicles[s]
8AP 600 T[t] 8AP 800 T 8AP 1000 T 8AP 1200 T	600 N⋅m (443 lb⋅ft) · 2017 800 N⋅m (590 lb⋅ft) · 2017 1,000 N⋅m (738 lb⋅ft) · 2017 1,200 N⋅m (885 lb⋅ft) · 2017[u]		65[v] 115	65[v] 115	62 122	27 105	2 3	7.6522	1.3374
Ratio ${\displaystyle i_{n}}$	−4.2501 ${\displaystyle -{\tfrac {10,672}{2,511}}}$	4.8889 ${\displaystyle {\tfrac {44}{9}}}$	3.1235 ${\displaystyle {\tfrac {253}{81}}}$	2.0334 ${\displaystyle {\tfrac {1,584}{779}}}$	1.6389 ${\displaystyle {\tfrac {59}{36}}}$	1.2541 ${\displaystyle {\tfrac {123,164}{98,209}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8400 ${\displaystyle {\tfrac {2,116}{2,519}}}$	0.6389 ${\displaystyle {\tfrac {23}{36}}}$
Step	0.8693		1.5652	1.5361	1.2407	1.3068	1.2541	1.1905	1.3148
8AP 1200 S [w]	1,200 N⋅m (885 lb⋅ft) · 2017[u]		65[v] 115	65[v] 115	65[v] 115	27<br105	2 3	7.6522	1.3374
Ratio ${\displaystyle i_{n}}$	−3.7569 ${\displaystyle -{\tfrac {3,956}{1,053}}}$	4.8889 ${\displaystyle {\tfrac {44}{9}}}$	3.1235 ${\displaystyle {\tfrac {253}{81}}}$	2.0334 ${\displaystyle {\tfrac {1,584}{779}}}$	1.6389 ${\displaystyle {\tfrac {59}{36}}}$	1.2676 ${\displaystyle {\tfrac {49,572}{39,107}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8305 ${\displaystyle {\tfrac {828}{997}}}$	0.6389 ${\displaystyle {\tfrac {23}{36}}}$
Step	0.7685		1.5652	1.5361	1.2407	1.2929	1.2676	1.2041	1.2999
Ratio R & even	${\displaystyle {\tfrac {R_{2}(S_{3}S_{4}-R_{3}R_{4})}{S_{3}S_{4}(S_{2}+R_{2})}}}$		${\displaystyle {\tfrac {R_{2}(S_{4}+R_{4})}{(S_{2}+R_{2})S_{4}}}}$		${\displaystyle 1+{\tfrac {S_{2}R_{1}}{S_{1}(S_{2}+R_{2})}}}$		${\displaystyle {\tfrac {1}{1}}}$		${\displaystyle {\tfrac {R_{2}}{S_{2}+R_{2}}}}$
Ratio odd		${\displaystyle {\tfrac {S_{4}+R_{4}}{S_{4}}}}$	${\displaystyle {\tfrac {(S_{1}+R_{1})(S_{4}+R_{4})}{S_{4}R_{1}+S_{1}(S_{4}+R_{4})}}}$		${\displaystyle {\tfrac {S_{1}R_{2}R_{4}(S_{3}+R_{3})+S_{2}S_{3}(S_{1}+R_{1})(S_{4}+R_{4})}{S_{1}R_{4}(S_{3}(S_{2}+R_{2})+R_{2}R_{3})+S_{2}S_{3}S_{4}(S_{1}+R_{1})}}}$			${\displaystyle {\tfrac {R_{2}(S_{3}+R_{3})}{R_{2}(S_{3}+R_{3})+S_{2}S_{3}}}}$

Variants and Applications

See also

• List of Chrysler transmissions
• List of ZF transmissions

References

External links

• Official website

This page was last edited on 14 April 2024, at 22:11