Regearing 2015 silverado

warfmatt · August 31, 2016

I have a 2015 Chevy Silverado Z71 4x4 with 3:08 gears, I am running 37s and notice lag between 1st and 2nd pretty bad and anything over 55, especially pulling a bay boat or trailer. I am looking to install bigger gears but haven't had much luck finding the answers I'm looking for. What size gears do I need to run with 37s? And is it done successfully without getting ABS lights or other issues?

Penguin VII · August 31, 2016

To get back to stock performance you need to do a little math.

(new tire size x old gear ratio) / old tire size = New gear ratio

I think the default tire size is like 31.5" so you would be:

(37 x 3:08) / 31.5 = 3:617

Although that seems low, but could be because you were running low gears to begin with. I'd assume you would probably want to look at some 4:10s but wait to hear back from someone who knows better than I.

What size lift are you running to fit 37s?

tnchevy · August 31, 2016

You probably need either a 3.73 or 4.10 gears (front and back if it is 4x4). The lower gear ratio will help greatly on take off and in your case may actually improve your mpg's a little because you are not having to give it as much gas to get moving. It won't be cheap though! Do a search on here, the topic has been covered before.