ATSG CONFIRMED FIX - NOVEMBER 2022

2017 Chevy Silverado 1500 6.2L 8L90


Complaint: After rebuilding, transmission has a tie-up on a 7-6 with harsh downshift and setting code PO747, ss1 stuck on, 1-2-7-8-R not released, and going into failsafe.

Cause: The 1-2-7-8-R clutch return spring which is a Bellville Spring was installed upside down.

Correction: Assemble the spring in correct direction which is dish side down.

Part numbers related to the repair: NA

Year Make and Model of the Vehicle: 2017 Chevy Silverado 1500 6.2L

Mileage: 90,545

Shop Name: Atec Transmission

Transmission: 8L90

Additional Notes: Vehicle only came to the shop with a torque converter shudder, new complaint was due to rebuilder error, with the Bellville spring being installed wrong this was causing too slow of a release for the 1-2-7-8-R clutch which was causing the tie-up and harsh downshift.

Pictures/Diagram: Included below. Pictures are of the clutch application and clutch spring being installed in the correct position.




Find thousands of Confirmed Fixes, Quick Reference Guides, Bulletins & Video Tutorials in the ATSG Member exclusive Tech Library along with unlimited calls into the tech hotline by joining ATSG today: https://bit.ly/ATSGmembership


ATSG Logo


the fix

the fix