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6L 45 · 6L 50 · 6L 80 · 6L 90
A Hydra-Matic 6L80 transmission at the Ypsilanti Automotive Heritage Museum
Overview
Manufacturer	General Motors
Production	2005–present
Body and chassis
Class	6-Speed Longitudinal Automatic Transmission
Related	Aisin AWTF-80 SC Ford 6R ZF 6HP
Chronology
Predecessor	4L60-E · 4L65-E 5L40-E · 5L50
Successor	8L 45 · 8L 90

The 6L 50 (and similar 6L 45) is a 6-speed longitudinally-mounted automatic transmission produced by General Motors. It is very similar in design to the larger GM 6L 80 and 6L 90, and is produced at GM Powertrain plants in Toledo, Ohio; Silao, Guanajuato, Mexico; and by the independent Punch Powerglide company in Strasbourg, France.

This transmission features clutch to clutch shifting, eliminating the bands used on older transmission designs. The 6L 50 debuted for the 2007 model year on the V8-powered versions of the Cadillac STS sedan and Cadillac SRX crossover, and replaces the 5L40-E and 5L50 in GM's lineup. The 6L 45 version is used in certain BMW vehicles and the Cadillac ATS, as part of either rear-wheel drive and all-wheel drive powertrains.

The 6L 80 (and similar 6L 90) is a 6-speed automatic transmission built by General Motors at its Willow Run Transmission plant in Ypsilanti, MI. It was introduced in late 2005, and is very similar in design to the smaller 6L 45 and 6L 50, produced at GM Powertrain in Strasbourg, France.

It features clutch to clutch shifting, eliminating the one-way clutches used on older transmission designs. In February 2006 GM announced that it would invest $500 million to expand the Toledo Transmission plant in Toledo, Ohio to produce the 6L 80 in 2008. Torque rating 6L 80 590 lb⋅ft (800 N⋅m), 6L 90 885 lb⋅ft (1,200 N⋅m) and is adaptable to rear-wheel drive and all-wheel drive applications.

1. Differences in gear ratios have a measurable, direct impact on vehicle dynamics, performance, waste emissions as well as fuel mileage
2. for comparison purposes only

Specifications

Basic concept

A conventional planetary gearset and a compound Ravigneaux gearset is combined in a Lepelletier gear mechanism, to reduce both the size and weight. It was first realized with the 6HP from ZF Friedrichshafen. Like all transmissions realized with Lepelletier transmissions, the 6L also dispenses with the use of the direct gear ratio, making it one of the very few automatic transmission concepts without such a ratio.

It also has the capability to achieve torque converter lock-up on all 6 forward gears, and disengage it completely when at a standstill, significantly closing the fuel efficiency gap between automatic and manual transmissions.

Technical data

Gear Ratios

With Assessment		Planetary Gearset: Teeth Lepelletier Gear Mechanism			Count	Total Center	Avg.
		Simple	Ravigneaux
Model Type	Version First Delivery	S1 R1	S2 R2	S3 R3	Brakes Clutches	Ratio Span	Gear Step
Gear Ratio	R ${\displaystyle {i_{R}}}$	1 ${\displaystyle {i_{1}}}$	2 ${\displaystyle {i_{2}}}$	3 ${\displaystyle {i_{3}}}$	4 ${\displaystyle {i_{4}}}$	5 ${\displaystyle {i_{5}}}$	6 ${\displaystyle {i_{6}}}$
Step	${\displaystyle -{\tfrac {i_{R}}{i_{1}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{1}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{2}}}}$	${\displaystyle {\tfrac {i_{2}}{i_{3}}}}$	${\displaystyle {\tfrac {i_{3}}{i_{4}}}}$	${\displaystyle {\tfrac {i_{4}}{i_{5}}}}$	${\displaystyle {\tfrac {i_{5}}{i_{6}}}}$
Δ Step			${\displaystyle {\tfrac {i_{1}}{i_{2}}}:{\tfrac {i_{2}}{i_{3}}}}$	${\displaystyle {\tfrac {i_{2}}{i_{3}}}:{\tfrac {i_{3}}{i_{4}}}}$	${\displaystyle {\tfrac {i_{3}}{i_{4}}}:{\tfrac {i_{4}}{i_{5}}}}$	${\displaystyle {\tfrac {i_{4}}{i_{5}}}:{\tfrac {i_{5}}{i_{6}}}}$
Shaft Speed	${\displaystyle {\tfrac {i_{1}}{i_{R}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{1}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{2}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{3}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{4}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{5}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{6}}}}$
Δ Shaft Speed	${\displaystyle 0-{\tfrac {i_{1}}{i_{R}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{1}}}-0}$	${\displaystyle {\tfrac {i_{1}}{i_{2}}}-{\tfrac {i_{1}}{i_{1}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{3}}}-{\tfrac {i_{1}}{i_{2}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{4}}}-{\tfrac {i_{1}}{i_{3}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{5}}}-{\tfrac {i_{1}}{i_{4}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{6}}}-{\tfrac {i_{1}}{i_{5}}}}$
6L 45 · MYA 6L 50 · MYB	500 N⋅m (369 lb⋅ft) 2005	49 89	37 47	47 97	2 3	6.0346 1.6548	1.4326
Gear Ratio	−3.2001 ${\displaystyle -{\tfrac {13,386}{4,183}}}$	4.0650 ${\displaystyle {\tfrac {13,386}{3,293}}}$	2.3712 ${\displaystyle {\tfrac {15,617}{63586}}}$	1.5506 ${\displaystyle {\tfrac {138}{89}}}$	1.1567 ${\displaystyle {\tfrac {13,386}{11,573}}}$	0.8532 ${\displaystyle {\tfrac {13,386}{15,689}}}$	0.6736 ${\displaystyle {\tfrac {97}{144}}}$
Step	0.7872	1.0000	1.7143	1.5293	1.3406	1.3557	1.2662
Step 2			1.1210	1.1408	0.9889	1.0703
Speed	-1.2703	1.0000	1.7143	2.6216	3.5144	4.7643	6.0346
Δ Speed	1.2703	1.0000	0.7143	0.9073	0.8928	1.2499	1.2703
6L 80 · MYC 6L 90 · MYD	800 N⋅m (590 lb⋅ft) 2005	50 94	35 46	46 92	2 3	6.0401 1.6384	1.4329
Gear Ratio	−3.0638 ${\displaystyle -{\tfrac {144}{47}}}$	4.0267 ${\displaystyle {\tfrac {6,624}{1,645}}}$	2.3635 ${\displaystyle {\tfrac {3,888}{1,645}}}$	1.5319 ${\displaystyle {\tfrac {72}{47}}}$	1.1522 ${\displaystyle {\tfrac {6,624}{5,749}}}$	0.8521 ${\displaystyle {\tfrac {144}{169}}}$	0.6667 ${\displaystyle {\tfrac {2}{3}}}$
Step	0.7609	1.0000	1.7037	1.5429	1.3296	1.3522	1.2781
Step 2			1.1043	1.1604	0.9832	1.0580
Speed	-1.3143	1.0000	1.7037	2.6286	3.4948	4.7258	6.0401
Δ Speed	1.3143	1.0000	0.7037	0.9249	0.8662	1.2310	1.3143
ZF 6HP	All · 2000	37 71	31 38	38 85	2 3	6.0354 1.6977	1.4327
Gear Ratio	−3.4025 ${\displaystyle -{\tfrac {4,590}{1,349}}}$	4.1708 ${\displaystyle {\tfrac {9,180}{2,201}}}$	2.3397 ${\displaystyle {\tfrac {211,140}{90,241}}}$	1.5211 ${\displaystyle {\tfrac {108}{71}}}$	1.1428	0.8672 ${\displaystyle {\tfrac {4,590}{5,293}}}$	0.6911 ${\displaystyle {\tfrac {85}{123}}}$
Step	0.8158	1.0000	1.7826	1.5382	1.3311	1.3178	1.2549
Step 2			1.1589	1.1559	1.0101	1.0502
Speed	-1.2258	1.0000	1.7826	2.7419	3.6497	4.8096	6.0354
Δ Speed	1.2258	1.0000	0.7826	0.9593	0.9078	1.1599	1.2258
Ratio R & Even	${\displaystyle -{\tfrac {R_{3}(S_{1}+R_{1})}{R_{1}S_{3}}}}$	${\displaystyle {\tfrac {R_{3}(S_{1}+R_{1})(S_{2}+R_{2})}{R_{1}S_{2}(S_{3}+R_{3})}}}$		${\displaystyle {\tfrac {R_{2}R_{3}(S_{1}+R_{1})}{R_{2}R_{3}(S_{1}+R_{1})-S_{1}S_{2}S_{3}}}}$		${\displaystyle {\tfrac {R_{3}}{S_{3}+R_{3}}}}$
Ratio Odd	${\displaystyle {\tfrac {R_{2}R_{3}(S_{1}+R_{1})}{R_{1}S_{2}S_{3}}}}$		${\displaystyle {\tfrac {S_{1}+R_{1}}{R_{1}}}}$		${\displaystyle {\tfrac {R_{3}(S_{1}+R_{1})}{R_{3}(S_{1}+R_{1})+S_{1}S_{3}}}}$
Algebra And Actuated Shift Elements
Brake A		❶	❶	❶	❶
Brake B	❶			❶		❶
Clutch C			❶				❶
Clutch D	❶	❶
Clutch E					❶	❶	❶
All 6L-transmissions are based on the Lepelletier gear mechanism, first realized in the ZF 6HP gearbox ^ Other gearboxes using the Lepelletier gear mechanism see infobox Layout Input and output are on opposite sides Planetary gearset 1 is on the input (turbine) side Input shafts are R1 and, if actuated, C2/C3 (the combined carrier of the compound Ravigneaux gearset 2 and 3) Output shaft is R3 (ring gear of gearset 3: outer Ravigneaux gearset) Total Ratio Span (Total Ratio Spread · Total Gear Ratio) ${\displaystyle {\tfrac {i_{n}}{i_{1}}}}$ 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 Ratio Span's Center ${\displaystyle (i_{n}i_{1})^{\tfrac {1}{2}}}$ The center indicates the speed level of the transmission Together with the final drive ratio it gives the shaft speed level of the vehicle Average Gear Step ${\displaystyle ({\tfrac {i_{n}}{i_{1}}})^{\tfrac {1}{n-1}}}$ With decreasing step width the gears connect better to each other shifting comfort increases Sun 1: sun gear of gearset 1 Ring 1: ring gear of gearset 1 Sun 2: sun gear of gearset 2: inner Ravigneaux gearset Ring 2: ring gear of gearset 2: inner Ravigneaux gearset Sun 3: sun gear of gearset 3: outer Ravigneaux gearset Ring 3: ring gear of gearset 3: outer Ravigneaux gearset ^ Standard 50:50 — 50 % Is Above And 50 % Is Below The Average Gear Step — With steadily decreasing gear steps (yellow highlighted line Step) and a particularly large step from 1st to 2nd gear the lower half of the gear steps (between the small gears; rounded down, here the first 2) is always larger and the upper half of the gear steps (between the large gears; rounded up, here the last 3) 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) ^ Standard 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) ^ Standard 1:2 — Gear Step 1st To 2nd Gear As Small As Possible — With continuously decreasing gear steps (yellow marked line Step) the largest 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) ^ From large to small gears (from right to left) ^ Standard STEP — From Large To Small Gears: Steady And Progressive Increase In Gear Steps — Gear steps should increase: Δ Step (first green highlighted line Δ Step) is always greater than 1 As progressive as possible: Δ Step is always greater than the previous step Not progressively increasing is acceptable (red) Not increasing is unsatisfactory (bold) ^ Standard SPEED — From Small To Large Gears: Steady Increase In Shaft Speed Difference — Shaft speed differences should increase: Δ Shaft Speed (second line marked in green Δ (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) First gearbox on the market to use the Lepelletier gear mechanism for comparison purposes only Blocks R2 and S3 Blocks C2 (carrier 2) and C3 (carrier 3) Couples C1 (carrier 1) and S2 Couples C1 (carrier 1) with R2 and S3 Couples R1 with C2 (carrier 2) and C3 (carrier 3)

Applications

6L 45 · MYA

• 2007–2010: BMW X3 - 3.0si / 2.5si / 3.0i
• 2007–2013: BMW 3 series - 330(x)i / 328(x)i / 325(x)i / 323i / 320i / 318i / 316i
• 2007–2019: BMW 1 series - 130i / 128i / 125i / 120i / 118i / 116i
• 2009–2015: BMW X1 (E84) - 2.8i xDrive / 2.5i xDrive / 1.8i sDrive
• 2013–2015: Cadillac ATS
• 2010–2013: Cadillac SLS
• 2012–2017: Chevrolet Caprice PPV V6
• 2011–2013: Holden VE Commodore, Calais, SV6
• 2013–2017: Holden VF Commodore, Calais, SV6

6L 50 · MYB

• 2007–2011: Cadillac SLS
• 2007–2011: Cadillac STS
• 2007–2009: Cadillac SRX
• 2008–2015: Cadillac CTS
• 2010–2015: Camaro LS/LT (V6 Models)
• 2009–2011: Holden VE Commodore / Holden VE Berlina / Holden VE Calais / Chevrolet Lumina / Chevrolet Omega
• 2009–2011: Holden WM Statesman/Caprice / Daewoo Veritas
• 2015–2022: Chevrolet Colorado
• 2017–2020: Tata Hexa
• 2019–present: UAZ Patriot
• 2022–present: Bremach

6L 80 · MYC

• 2006–2009 Cadillac XLR-V
• 2006–2013 Chevrolet Corvette
• 2006 Holden VE Commodore/2008-2009 Pontiac G8
• 2006–2013 Holden/Chevrolet WM Statesman/Caprice
• 2014–2017 Holden/Chevrolet WN Statesman/Caprice
• 2007–2013 GMC Sierra Denali
• 2009–2013 Chevrolet Silverado 1500 5.3 (ext. & crew cab), 6.2
• 2009–2013 GMC Sierra 1500 5.3 (ext. & crew cab), 6.2
• 2010–2013 Chevrolet Silverado 1500 5.3 (reg. cab)
• 2010–2013 GMC Sierra 1500 5.3 (reg. cab)
• 2006–2009 Cadillac STS-V
• 2007–2015 Cadillac Escalade
• 2007–2015 Cadillac Escalade ESV
• 2007–2013 Cadillac Escalade EXT
• 2007–2015 GMC Yukon Denali
• 2009–2020 Chevrolet Tahoe
• 2009–2020 GMC Yukon
• 2009–2020 Chevrolet Suburban 1500
• 2009–2020 GMC Yukon XL
• 2008–2009 Hummer H2
• 2014–2019 (K2XX) Chevrolet Silverado/GMC Sierra 1500
• 2010–2015 Chevrolet Camaro
• 2011–2017 Chevrolet Caprice PPV
• 2011(September)–2013 Holden VE Commodore Series 2(MY 2012)
• 2014–2017 Holden VF Commodore / Chevrolet SS
• 2009–2013 Chevrolet Avalanche
• 2019–2021 (T1XX) Chevrolet Silverado/GMC Sierra 1500

6L 90 · MYD

• 2007–2014 Chevrolet Silverado 2500HD/3500 HD 6.0
• 2007–2014 GMC Sierra 2500HD/3500HD 6.0
• 2010–present Chevrolet Express 2500–3500
• 2010–present GMC Savana 2500–3500
• 2008–2019 Chevrolet Suburban 2500
• 2009–2013 Cadillac CTS-V
• 2012–2015 Chevrolet Camaro ZL1
• 2015–2019 Chevrolet Silverado 2500HD/3500 HD 6.0
• 2015–2019 GMC Sierra 2500HD/3500HD 6.0
• 2020–2023 Chevrolet Silverado 2500HD/3500 HD 6.6 L8T
• 2020–2023 GMC Sierra 2500HD/3500HD 6.6 L8T

See also

• List of GM transmissions
• "GM Launches More Fuel-Saving Six-Speed Automatic Transmissions". GM Media Online. Retrieved June 18, 2006.
• Cadillac PDF info on 6L 80-E Transmission: http://www.cadillacfaq.com/stsfaq/tsb/data/tsb/05-07-30-023.pdf
• "GM Ypsilanti Begins 6-Speed Production". Automotive Design and Production. Archived from the original on March 3, 2006. Retrieved January 3, 2006.

References

1. Riley, Mike (2013-09-01). "Lepelletier Planetary System". Transmission Digest. Archived from the original on 2023-06-21. Retrieved 2023-03-03.
2. Csere, Csaba (March 2012). Dissected: 2013 Cadillac ATS. Car and Driver. ISBN 9781858941905. OCLC 38224673. Archived from the original on 2012-10-30. Retrieved 2012-11-21.
3. "2015 Chevrolet Colorado Specifications". GM. Retrieved 2014-10-14.
4. "Bremach Suv".
5. "GM Corporate Newsroom - United States - Home". media.gm.com. Retrieved 2016-10-26.

External links

• General Motors Powertrain Division
• https://gmauthority.com/blog/gm/gm-transmissions/mya/
• https://gmauthority.com/blog/gm/gm-transmissions/myb/
• https://gmauthority.com/blog/gm/gm-transmissions/myc/
• https://gmauthority.com/blog/gm/gm-transmissions/myd/

• General Motors transmissions