Could Timbren Kit # T28MR for 2025 GMC Sierra 1500 fit AT4 Model

Updated 02/10/2025 | Published 01/29/2025

Question:

Why doesnt this work for the AT4s? Would removing the spacer help?

asked by: Shane T

Expert Reply:

Hey Shane, sorry for any confusion but the AT4 models of the 2025 GMC Sierra 1500 have a factory 2 inch lift which is why the Timbren kit part # T28MR would not fit. What you could do is order the kit and install it and then let me know how much of a gap is created between the bottom of the Timbren and where it contacts axle. With that info I could let you know how big of a spacer you would need to take up the additional space created by the lift kit.

expert reply by: Jameson C

Shane T.

2/10/2025

I ended up not purchasing the Truck. However, I have a kit similar to this with a 1-inch spacer (both purchased from etrailer) on my 5th gen 4Runner. The spacer was purchased separate, because I had a two-inch lift installed. Had I not done that the Timbren would be ineffective, unless I'm at near max payload capacity. I also have another brand kit up front, but that's here nor there. So, it doesn't make sense that a truck with a factory 2-lift would struggle to fit it, when the trucks without the lift fit it without apparent issue. Unless there's something included in the AT4 package that isn't listing blocking the install of the kit.

Jameson C.

2/10/2025

@ShaneT Yeah it's not unheard of that certain packages on trucks have totally different suspension setups. In this case I would assume you'd just need the correct spacers.