Correct Timbren Suspension Enhancement For 2021 GMC Sierra 1500 AT4

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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

1

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

1

Answer 1

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…

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Answer 2

When installing a Suspension Enhancement System on your 2019 GMC Sierra 1500 The Timbren Suspension Enhancement System - Rear Axle #T28MR are confirmed to fit. The system has a 8,600 pound capacity that reduces vehicle sag, and increases stability.…

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Answer 3

Yes, the Timbren Suspension Enhancement System #T28MR will be the best option when it comes to cost-effectiveness. This will fit with your 2021 Chevrolet Silverado 1500 Z71 Trail Boss but you'll want to make sure these fit the gap properly. The…

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Answer 4

Kurt, it looks like the reason the AirLift Air Springs won't work with the adaptive ride control because of the way the springs install in the suspension, but the good news is that there is an alternative; the Firestone Ride-Rite Air Helper…

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Answer 5

The difference between the Class II and Class III hitches has to do with their Gross Trailer Weight (GTW), their Tongue Weight (TW), and their Hitch Receiver Size. Class II trailer hitch receivers have a 1-1/4 inch receiver and can be rated up to…

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Answer 6

In order to determine the torque rating for the lug nuts on your trailer you will need to know check out the chart I attached that shows all of the torque specs for all the trailer lugs available based on stud size, wheel material and wheel size.

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Answer 7

Hey Bryan, that's a good question. The pricing can definitely be misleading, but I wouldn't use it to judge the quality of the tire. A lot of that comes down to promotions, inventory, and whether you're looking at a tire by itself or…

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Answer 8

A 4-Way trailer connector has the basic lighting functions only; running lights, left turn signal and brake lights, right turn signal and brake lights, and ground. A 7-Way has these functions and a 12 volt circuit, a circuit for electric trailer…

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Answer 9

Hey Doug! The Firestone Ride-Rite Air Helper Springs #F35FV are the right kit for your 2026 Ford F-350 FX4 dually. However, you will need to measure to be sure it fits. The distance from the top of your rear axle to the top of the jounce bump stop…

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Answer 10

Hi Paul, you’re definitely on the right track here, and I can help you narrow this down with confidence. With your tandem 3,500 lb Dexter axles and 33 inch spacing, both the Dexter EZ Flex part #K71-652-00 and the Lippert Road Armor part #LC53CK are…

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Answer 11

According to Blue Ox, it'll take an experienced installer about 4 to 5 hours to complete the installation of their #BX1128 Base Plate Kit on a 2016 Jeep Grand Cherokee. The install isn't what I'd call super-difficult, but the installation…

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Answer 12

Yes, it will work. You'll just need to cut the Lance 6-pin connector out and rewire it into the etrailer Trailer Wiring 7-Way Upgrade Kit w/ Junction Box and RV Style Connector item #e99011. Here are the individual functions of that Lance 6-pin:…

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Correct Timbren Suspension Enhancement For 2021 GMC Sierra 1500 AT4

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