3-second answer: TTB trucks wear the outside edge when the camber is off (or the axle is sagging on the radius-arm bushings). The fix: camber bushings (adjustable, at the ball joints) if it's geometry, or radius arm bushings + springs if the axle is sagging. Check the radius arm bushings FIRST — a sagging axle reads as 'bad alignment' and eats tires no matter how many times you align it.
Why TTB eats tires
- The TTB beams pivot at the frame; ride height changes camber dramatically (that's why lifts need camber bushings/alignment).
- Worn radius arm bushings let the axle sag and toe out under load → outer-edge wear + that wandering feel.
- It's a beam axle with ball joints — any slop compounds into tire wear.
The fix order
- Radius arm bushings (see 4x4 & TTB) — sag + wear source #1.
- Ball joints (check them) — worn joints = wandering + wear.
- Camber bushings — if the alignment shows out-of-spec camber, the adjustable bushings fix it (they replace the stock camber sleeve at the upper/lower joint). ~$40-60 + alignment.
- Toe — set it per spec; toe-out on a lifted TTB is the tire-eater.
- Front wheel bearings / spindle nut (200 ft-lb) — loose bearings fake alignment problems.
The alignment reality
These trucks will never align like a modern car — and that's fine. A competent shop that knows TTB (or a good forum walkthrough) gets it close enough to wear tires evenly. Expect to pay for the camber bushings, not just the alignment.
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