Huge Rear Axle On My TRD Off-Road Trim - 9.5" Upgrade | 4th Gen Tacoma Forum

clovisb31 · 2026-03-20T20:49:26+00:00

Hello, I'm thinking about replacing the OE flooded lead acid battery with an equivalent size AGM type battery. The Tacoma charging system provides 13.9 Volts to the stock OE battery. An AGM battery typically needs 14.4-14.6 volts to properly charge. Is the alternator/charging system voltage able to be changed/increased to allow for proper AGM charging? Does anyone know what the procedure is? Is a dealer level Scan tool required to do this modification? Thanks in advance.

rustytaco

Administrator

Staff member

Feb 15, 2025

#1

For those wondering, Toyota did give us a lot of what we asked for in this new truck. One crazy important feature, the 9.5" rear axle. This axle is nearly as big as a Dana 60, only .25" smaller. Naturally, they are super strong. You could technically run a 40" tire with relatively little issues. My plan is to run 37s bare minimum in the next few months, and 40s only if I decide to throw it on portals. But I'm beyond stoked on the beefier rear end. Hopefully the front can keep up! The 3rd Gen had a max size of 8.75". While still a good size, these new ones are much better.

You must log in or register to reply here.