Harsh 5-4 Downshift and Harsh 1-2 Upshift – 2017 Chevrolet Colorado & GMC Canyon

NHTSA ID Number: 10205547

Manufacturer Communication Number: 21NA076

 

Summary

This technical bulletin provides a procedure to repair a worn spring in the transmission to correct the customers concern.

 

 


2 Affected Products

Vehicles

MAKEMODELYEAR
CHEVROLETeBay logoCOLORADO2017
GMCCANYON2017

 


Condition

Some customers may comment that their vehicle has developed a harsh 5-4 downshift and a harsh 1-2 upshift.

– The condition developed after approximately 25,000 miles (40,000 km). The harsh shift conditions may only be present when the transmission temperature is above approximately 110 F (43 C) degrees.

– The transmission may have acceptable transmission shift quality at lower operating temperatures.

 

Cause

This condition may be caused by the 2-3-4-6-8 Return Spring (527), has degraded overtime contributing to the condition

 

Correction

Replace the 2-3-4-6-8 Piston (526) and the 2-3-4-6-8 Return Spring and reseal the 2-3-4- 6-8 and 4-5-6-7-8 Reverse Clutch Assemble following published Service Information procedures.

 

Service Procedure

Refer to 2-3-4-6-8 and 4-5-6-7-8 Reverse Clutch Assembly Removal and 2-3-4-6-8 and 4-5-6-7-8 Reverse Clutch Disassemble and Assemble in SI.

 

Parts Information

Causal PartDescriptionPart NumberQty
XPiston, 2-3-4-6-8 Clutch242688811
XSpring, 2-3-4-6-8 Clutch Piston Return242922561
N/ASeal 2-3-4-6-8 Clutch Piston Dam INNER242501871
N/ASeal, Trans Fluid Cooler Pipe Fitting23135703
GM 23135703 SEAL-TRANS FLUID CLR PIPE FTG
  • Genuine Oem: Yes, Category 2: Cooling, Item Name: Pipe Assembly Gasket, Category 1: Cooling System
  • Brand: GM, Fitment Type: Direct Replacement, Part Ref# On Diagram: ONLY PART REFERENCE #3 ON THE DIAGRAM IS
  • Manufacturer Part Number: 23135703, Category 3: Transmission Oil Cooler, Quantity Needed: 1

Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API


 

1
N/ABolt, HFH Eng Motor Bracket11588740
GM Genuine Parts 11588740 Multi-Purpose Bolt
  • Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE)
  • GM Genuine Parts are designed, engineered and tested to rigorous standards, and are backed by General MotorseBay logo
  • GM Engineers design and validate OE parts specifically for your ChevroleteBay logo, BuickeBay logo, GMC, or CadillaceBay logo vehicle
  • GM regularly updates production and service part designs to integrate new materials and technologies

Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API


 

3
N/AGasket, Exh System Outlet Flange229719632
N/ABolt, Transaxle T/C11588468
11588468 BOLT 4.115

Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API


 

6
N/ARing, 1-3-5-6-7 Clutch Fluid Seal24266594
GM Genuine Parts 24266594 Automatic Transmission 1-3-5-6-7 Clutch Fluid Seal
  • GM-recommended replacement part for your GM vehicle’s original factory component
  • Offering the quality, reliability, and durability of GM OE
  • Manufactured to GM OE specification for fit, form, and function

Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API


 

2
N/AGasket, A/Trans Front Support Cover242848491
N/ASeal, A/Trans Case Front Cover242519061
N/ASeal, A/Trans Case Front Cover242817901
N/ARing, 4-5-6-7-8 Rev Clutch Piston242704461
N/ASeal, 4-5-6-7-8 Rev Piston Outer242610061
N/ASeal, 4-5-6-7-8 Rev Piston Inner242502111
N/ARing, 2-3-4-6-8 Clutch Piston Dam Retainer242610711
N/ASeal, 2-3-4-6-8 Clutch Piston Dam OUTER242501951
N/ASeal, 2-3-4-6-8 Clutch Piston242501981
N/ASeal, 4-5-6-7-8 Rev Clutch Piston242592711
N/ASeal, 4-5-6-7-8 Rev Clutch Piston Stop242502071
N/ASeal, 2-3-4-6-8 Clutch Piston Dam242610242
N/ASeal, Turbine Shaft O-ring kit086626861
N/ABolt, A/Trans Case Front Cover1154820111
N/AMobil 1 Synthetic ULV HP Fluid (US)19417577As Required
N/AMobil 1 Synthetic ULV HP Fluid (Can)19418066

 



1 Associated Document

Manufacturer Communications

MC-10205547-9999.pdf 76.66KB

 


NHTSA ID Number: 10201291

Manufacturer Communication Number: PIP5747A

 

Summary

This Preliminary information communicates to the dealer technician that engineering is investigating root cause of a harsh 1-2 and/or 5-4 shift on the 2017 ChevroleteBay logo Colorado and the 2017 GMC Canyon after mileage accumulation of approximately 25,000 miles. This Pi has been updated to refer the dealer technician to bulletin 21-NA-076 for information on how to address this concern.

 

1 Associated Document

Manufacturer Communications

Bulletin No.: PIP5747A
Published date: 06/21/2021

https://www.nhtsa.gov/recalls?nhtsaId=10201291

MC-10201291-9999.pdf 70.748KB

 


 

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Last update on 2026-05-27 / Affiliate links / Images from Amazon Product Advertising API


 

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