GM 8L transmission explained

8L 45 · 8L 90
Production:2014–
Manufacturer:General Motors
Class:8-speed longitudinal automatic transmission
Predecessor:6L 45 · 6L 50 · 6L 80 · 6L 90
Successor:10L 80 · 10L 90 · 10L 1000
Related:ZF 8HP

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 33lb. Gear ratios used enable a wide 7.0 ratio spread.

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

Applications

8L 45!Make!Model Years!Model!Final Drive Ratio
Cadillac2016–2019ATS
2016–2019CTS
2020–presentCT4
2016–presentCT6
Chevrolet2016–2019Camaro
2017–presentColorado
GMC2017–presentCanyon
8L 90!Make!Model Years!Model!Final Drive Ratio
Cadillac2015–2017Escalade[11] 3.23
2016–presentATS-V2.85
2016–presentCTS-V2.85
2016–presentCT63.27
Chevrolet2015–2019Corvette (C7) Stingray[12] 2.41 or 2.73
2015–2019Corvette (C7) Z06[13] 2.41
2019Corvette (C7) ZR12.73
2015–presentSilverado[14] 3.23 or 3.42
2015–presentColorado3.42
2016–2018Camaro SS2.77
2017–presentExpress
GMC2015–2017Yukon Denali · Denali XL3.23
2015–presentSierra3.23
2015–presentCanyon3.42
2017–presentSavana

Lawsuits

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

External links

Notes and References

  1. Web site: USA Information Guide Model Year 2018. 15 July 2019.
  2. Web site: Cadillac Introduces New 8-Speed Automatic on CT6. Cadillac Media USA. 20 March 2015 . Cadillac Media USA. 20 March 2015.
  3. Web site: Timur Apakidze · Saturation Dive: The GM 8L 90 8-Speed Transmission . TTAC: The Truth About Cars . 23 April 2014 . 12 April 2024.
  4. Web site: New 8-Speed Enables Quicker, More Efficient Corvette . www.gm.com . General Motors . 21 August 2014 . 20 August 2014 . dead . https://web.archive.org/web/20141222140302/http://www.gm.com/article.content_pages_news_us_en_2014_aug_0820-8speed_0820-corvette-8-speed-lead.html . 22 December 2014 .
  5. https://poweredsolutions.gm.com/products/8l45-8-speed-transmission/
  6. https://poweredsolutions.gm.com/products/8l90-8-speed-transmission/
  7. Web site: Transmission Repair Cost Guide. 15 July 2019.
  8. Web site: WIT · Whatever It Takes · Automatic Transmission Parts Catalog 2018+2019 Page 268. 15 July 2019.
  9. 8HP 70 Repair Manual · Picture 10106 p. 110 · Saarbruecken 2014 · https://avtgr.ru/upload/data/pdf/zf_instructions/8HP70.pdf
  10. Web site: Timur Apakidze · Saturation Dive: ZF 8-Speed Automatic. TTAC: The Truth About Cars . 11 March 2014 . 7 July 2019.
  11. Web site: 2015 Cadillac Escalade Updated with 8L90 8-Speed Automatic and More Tech [Photo Gallery]]. 11 August 2014 . 12 August 2014.
  12. Web site: Chevrolet Confirms 2015 Corvette Stingray To Utilize 8L90 Eight-Speed Gearbox. 9 April 2014.
  13. Web site: Supercharged 2015 Chevy Corvette Z06 takes the C7 beyond the ZR1 [w/video]]. 25 January 2014.
  14. Web site: GM confirms 2015 Silverado, Sierra to get 8-speed automatic. 18 June 2014.
  15. Web site: Class Action Lawsuit Filed Over Alleged Shifting Defect in Certain General Motors Transmissions. 19 December 2018 . 2 February 2019.