Correct Timbren Suspension Enhancement For 2021 GMC Sierra 1500 AT4

Updated 06/01/2023 | Published 05/31/2023

Question:

Timbren GMRS15 is the recommended set from Timbren for a 2021 GMC SIERRA AT4 however I see you conflicting comments on this as I saw one where you said the AT4 would be the only model to pose an issue you confirmed with Timbren and this post that you say it works great for the AT4. Which is it? I believe the only difference is the 2 inch factory lift in the AT4 but I want to confirm before purchasing that this is exactly what I need. Thanks

asked by: Mark S

Helpful Expert Reply:

I reached out directly to Timbren for you, and they told me the correct fit for your 2021 GMC Sierra 1500 AT4 was indeed the Timbren Suspension Enhancement System # T28MR.

expert reply by: Kyle S