How to increase oil’s load carrying strength without changing viscosity

“I got the AW10 Antiwear for my old Jeep Wrangler. It’s old but in great shape. I’ve driven it across the country and back, I take it off road a lot, and I take really good care of it, but I’ve noticed over time the gear changes getting worse – slower and erratic erratic at times. I replaced the fluid, but that didn’t help. It’s then that I added the Antiwear to it, and immediately it improved incredibly! Gear shifts were like brand new, so smooth and quiet. It feels like a different vehicle. Really, an incredible improvement.“
Mike E, UT