← Back to TekJeep AI · All fitment answers
Will 40-inch tires fit a TJ Wrangler with a 4.5-inch lift?
Fitment answer · Updated October 27, 2026
Short answer
Not realistically. 40s on a 4.5-inch TJ need major fender cutting, high bump stops, 1-ton-class axles and usually a stretch; most 40-inch TJs run 6+ inches.
Shop the gear for this build ↓ Tires, deflators and a compressor picked for this setup.
What you usually need
- Flat or trimmed fenders.
- Bump stops sized to the lift.
- Axle upgrades; stock Dana 30/35 axles are weak for big tires.
- Heavy-duty steering and a driveline check.
Regearing
40s call for 5.13 or 5.38 gears or lower. Compare ratios in the Tire & Gear Calculator before you buy gears.
Compare
Gear for this build
- Mud-terrain tires (search) — Louder on the highway; buy for real mud use.
- Staun tire deflators — Repeatable trail pressures.
- VIAIR 88P portable compressor — Air back up before the highway.
- YUNPEAK 1.26" × 30' kinetic recovery rope — Bigger tires, bigger trails: carry recovery gear.
Amazon Associates disclosure: As an Amazon Associate, TekJeep AI earns from qualifying purchases. These links include our affiliate tag tekjeep-20.
FAQ
Do 40s fit a TJ Wrangler with a 4.5-inch lift?
Not realistically.
What lift do 40s need on a TJ?
Usually 6+ inches plus heavy fabrication.
Do I need to regear?
40s call for 5.13 or 5.38 gears or lower.
Check your numbers
Use the free Tire & Gear Calculator to see speedometer error, highway RPM and a regear target, or ask TekJeep AI on the homepage with your year, trim, lift and wheel specs.
Related guides: All-terrain & mud-terrain tires · JK 2.5" lift overview
More fitment answers: 33s on a TJ Wrangler · 35s on a TJ Wrangler · 31s on a stock TJ · 33s on a 2" TJ · 35s on a 3" TJ · 33s on a stock TJ Rubicon · 35s on a TJ Rubicon · 35s on a 2" TJ
Fitment disclaimer: Clearance depends on exact tire size, wheel specs, suspension and how hard you flex. Confirm with your tire shop or installer before buying.
Tire size how-tos: How to read a tire size · Bolt pattern & backspacing · Regearing for bigger tires · Tire pressure after upsizing · Speedometer error · Rubbing fixes