Regear math, built for the phone in your garage
What gears do you need? Do the math once, buy once.
RegearReady is the regear math library for Jeep, Toyota, Bronco and classic 4x4 builds: a crawl-ratio calculator that uses your actual transmission, factory charts verified against manufacturer specs, and a decision system for a job that costs $1,000–$2,700 to do — and nearly as much to undo.
Start with the headline number
Crawl ratio — first gear × low range × axle — is the number every build thread quotes and the one the big free calculator never actually shows you. Here it is, from your real gearbox:
Platforms
Factory charts for the rigs people actually build
The calculators
The full math library
The paid layer
The Decision System: from "which ratio?" to a build sheet
Calculators answer questions. They don't decide, budget, or write the parts list. The Regear Decision System does — for a job where the wrong ratio costs a second set of gears and a second labor bill. One payment, yours to keep.
Included in the $39 Regear Decision System
Decision Worksheet
Your use mix — daily, trail, rock, tow — weighed against restore-stock math to land on a specific ratio, with the reasoning shown. Not a chart: a verdict for your rig.
Included in the $39 Regear Decision System
Cost Planner & Quote Check
The full 2026 cost stack — gears, install kits, labor, lockers, programmer — plus a side-by-side sheet that exposes what a shop quote is really charging for.
Included in the $39 Regear Decision System
Shopping-List Generator
Pick platform, ratio and lockers: get the exact buy list, including the carrier question answered before you order the wrong gears.
Included in the $39 Regear Decision System
Install & Break-In System
The install-day checklist, the locker while-you're-in-there checklist, printable build sheets, and the 500-mile break-in protocol that keeps new gears alive.
Regear Decision System
One-time payment · yours to keep
- Decision worksheet for your exact rig & use mix
- Per-axle carrier-break & max-ratio tables
- Cost planner + shop-quote comparison
- Shopping-list generator & printable build sheets
- Install, locker & 500-mile break-in checklists
- Per-platform speedometer recalibration guide
JL/JT Platform Pack
One-time payment · yours to keep
- Complete JL/JT factory crawl matrix (every trans × case × axle)
- XR 4.56/4.88 factory data, worked in full
- JL/JT regear worksheet with gear-by-gear RPM
- JL/JT shopping lists by axle pair
- Tazer vs ProCal vs dealer: recalibration deep-dive