Help with Real Diff Lock

I just bought an 11 Tacoma TX pro and I don’t know how to engage the rear lock differential. Any help would be greatly appreciated. Has no mods. It’s still stock

 

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I don’t know how to engage the rear lock diff.
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Must be in 4 low first to engage (only place it works) - push button and you should hear a clunk in the rear, if not put back in Drive if you just engaged 4 low from Neutral and move the steering wheel from side to side as you let your foot off the brake - that will allow the splines to line up in the axles with the locker. If all electronics are OK it should work and light comes on fully (not blinking)