Adjustable Rear Control Arms
10/25/2025
Alright, time to admit it—the lift ruined the 4Runner. I don’t know if it’s because it’s 2WD or because I squeezed a few extra inches out of it than advertised, but the suspension geometry on this thing has been an absolute nightmare. And that’s saying something, because every vehicle I’ve owned has had suspension mods.
Since moving, my daily drive has gone from a quick 20-minute city hop to nearly 50 minutes of Texas highway. And not your average highway either—the kind where the speed limit is a suggestion and the shoulder doubles as a passing lane. After a few weeks at those speeds, something just felt off.
I know what a driveline vibration feels like, and this had all the symptoms. It finally clicked that while I’ve spent all this time fighting the front suspension geometry, I haven’t done a thing to the rear. So, I grabbed a cheap digital angle gauge, crawled under the truck, and started measuring. I found it best to zero the gauge on the drive shaft as close to the transmission as possible and, with the help of some clamps, secure a piece of flat bar across the pinion flange and clamping my gauge to it. Sure enough—about 3 degrees off.
Time for new rear upper control arms.
After some searching, I went with OPT Offroad adjustable upper control arms for one reason—they can be adjusted while still on the vehicle. Every cheaper set I found would’ve required removing one end, adjusting, reinstalling, checking, and repeating. No thanks. For the extra money, I’ll take convenience and quality. Plus, being OPT Offroad, these things are seriously overbuilt—way more than my pavement princess will ever need.
Pulling the factory arms made the difference obvious. The OPTs are absolute tanks in comparison. They even came slightly longer out of the box, so I had to use a ratchet strap to line the axle up and get the bolts through. Once installed, I gave each side three full turns, rechecked my angles, two more turns and—driveshaft geometry was right back in spec.
Took it for a test drive and immediately felt an improvement. The vibration the steering wheel is completely gone and its just that standard lifted, body on frame feel.
Hopefully that’s it, that’s the end of the suspension struggles—At least until I put bigger tires…
My Clamp Contraption
Sketchy…But Worked
Readings After Install
