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GM 8L transmission - Wikipedia

GM 8L transmission

(Redirected from GM 8L90 transmission)

The Hydramatic 8L 45 is an eight-speed automatic transmission built by General Motors debuting in the 2016 Cadillac CT6. It is designed for use in longitudinal engine applications attached to the front-located engine[1] with a standard bell housing. It is a hydraulic (hydramatic) design sharing much with the 8L 90 transmission.[2] Estimated weight savings over the heavier duty 8L 90 is 33 lb (15 kg). Gear ratios used enable a wide 7.0 ratio spread.

8L 45 · 8L 90
Overview
ManufacturerGeneral Motors
Production2014–
Body and chassis
Class8-speed longitudinal automatic transmission
RelatedZF 8HP
Chronology
Predecessor6L 45 · 6L 50 · 6L 80 · 6L 90
Successor10L 80 · 10L 90 · 10L 1000

The 8L 90 is an eight-speed automatic transmission built by General Motors. It is designed for use in longitudinal engine applications either attached to the front-located engine[1] with a standard bell housing or in the rear of the car adjacent to the differential (as in the Corvette). It is a hydraulic (hydramatic) design. GM also produces a similar design with the smaller 8L 45.

Both gearboxes are based on the layout of the ZF 8HP transmission from 2008, with the only difference being that gearsets 1 and 3 are swapped.[3]

Specifications

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Gear Ratios[a][4]
Gear
Model
R 1 2 3 4 5 6 7 8 Total
Span
Avg.
Step
Compo-
nents
8L 45 · M5N · 2015 −3.928 4.615 3.038 2.065 1.658 1.259 1.000 0.849 0.658 7.011 1.321 4 Gearsets
2 Brakes
3 Clutches
8L 90 · M5U · 2014 −3.818 4.560 2.971 2.075 1.688 1.270 1.000 0.845 0.652 6.999 1.320
2008: 1st Version
8HP 70 · 2008 −3.297 4.696 3.130 2.104 1.667 1.285 1.000 0.839 0.667 7.043 1.322
  1. ^ Differences in gear ratios have a measurable, direct impact on vehicle dynamics, performance, waste emissions as well as fuel mileage

Applications

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8L 45
Make Model Years Model Final Drive Ratio
Cadillac 2016–2019 ATS
2016–2019 CTS
2020–present CT4
2016–present CT6
Chevrolet 2016–2019 Camaro
2017–present Colorado
GMC 2017–present Canyon
8L 90
Make Model Years Model Final Drive Ratio
Cadillac 2015–2017 Escalade[11] 3.23
2016–present ATS-V 2.85
2016–present CTS-V 2.85
2016–present CT6 3.27
Chevrolet 2015–2019 Corvette (C7) Stingray[12] 2.41[a] or 2.73[b]
2015–2019 Corvette (C7) Z06[13] 2.41
2019 Corvette (C7) ZR1 2.73
2015–present Silverado[14] 3.23[a] or 3.42[c]
2015–present Colorado 3.42
2016–2018 Camaro SS 2.77
2017–present Express[d]
GMC 2015–2017 Yukon Denali · Denali XL 3.23
2015–present Sierra[14] 3.23
2015–present Canyon 3.42
2017–present Savana[d]
  1. ^ a b Standard
  2. ^ Z51
  3. ^ Maximum Trailering Package
  4. ^ a b 2.8 L diesel engine and 4.3 L gas engine only

Lawsuits

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The 8L 90 is the subject of a class-action lawsuit filed in December 2018 that alleges the transmission suffers from persistent "shudder" issues and that GM has known about the problems since its introduction and has failed to provide a solution, instead choosing to wait until the unit is out of warranty.[15]

See also

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References

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  1. ^ a b "USA Information Guide Model Year 2018" (PDF). Retrieved 15 July 2019.
  2. ^ "Cadillac Introduces New 8-Speed Automatic on CT6". Cadillac Media USA. Cadillac Media USA. 20 March 2015. Retrieved 20 March 2015.
  3. ^ "Timur Apakidze · Saturation Dive: The GM 8L 90 8-Speed Transmission". TTAC: The Truth About Cars. 23 April 2014. Retrieved 12 April 2024.
  4. ^ "New 8-Speed Enables Quicker, More Efficient Corvette". www.gm.com. General Motors. 20 August 2014. Archived from the original on 22 December 2014. Retrieved 21 August 2014.
  5. ^ https://poweredsolutions.gm.com/products/8l45-8-speed-transmission/
  6. ^ https://poweredsolutions.gm.com/products/8l90-8-speed-transmission/
  7. ^ "Transmission Repair Cost Guide". Retrieved 15 July 2019.
  8. ^ "WIT · Whatever It Takes · Automatic Transmission Parts Catalog 2018+2019 Page 268". Retrieved 15 July 2019.
  9. ^ a b 8HP 70 Repair Manual · Picture 10106 p. 110 · Saarbruecken 2014 · https://avtgr.ru/upload/data/pdf/zf_instructions/8HP70.pdf
  10. ^ a b "Timur Apakidze · Saturation Dive: ZF 8-Speed Automatic". TTAC: The Truth About Cars. 11 March 2014. Retrieved 7 July 2019.
  11. ^ "2015 Cadillac Escalade Updated with 8L90 8-Speed Automatic and More Tech [Photo Gallery]". 11 August 2014. Retrieved 12 August 2014.
  12. ^ "Chevrolet Confirms 2015 Corvette Stingray To Utilize 8L90 Eight-Speed Gearbox". Retrieved 9 April 2014.
  13. ^ "Supercharged 2015 Chevy Corvette Z06 takes the C7 beyond the ZR1 [w/video]". Retrieved 25 January 2014.
  14. ^ a b "GM confirms 2015 Silverado, Sierra to get 8-speed automatic". Retrieved 18 June 2014.
  15. ^ "Class Action Lawsuit Filed Over Alleged Shifting Defect in Certain General Motors Transmissions". 19 December 2018. Retrieved 2 February 2019.
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