AX15 4.31:1 Low First Gear Conversion

Upgrade the Jeep AX15 with a lower first gear that improves crawl control, launch feel, and torque multiplication in heavier builds and technical terrain. This conversion changes first gear from 3.83:1 to 4.31:1, helping reduce clutch slip and making the drivetrain easier to manage at slow speeds.

What It Does

A deeper first gear increases low-speed torque at the wheels and gives you finer throttle modulation—useful for rock crawling, steep starts, towing, and large-tire builds where the stock first gear feels tall.

Key Features

• Changes AX15 first gear ratio from 3.83:1 to 4.31:1
• Improves crawl ratio and low-speed control
• Reduces clutch slip for smoother starts and less heat/wear
• Precision-cut for proper engagement and long service life

Installation & Fitment

Recommended during an AX15 rebuild or overhaul. First gear replacement requires transmission disassembly, inspection, and proper setup to ensure correct engagement and long-term reliability.

• Fits: AX15 manual transmissions
• Install timing: during a full rebuild

Related Parts

AX15 Transmission Master Rebuild Kit Deluxe

If you are installing gears during a refresh, consider Novak’s master rebuild kit for a complete, long-term AX15 solution.

AX15 Short Throw Shifter Kit

This is an all-new, all-6061 aluminum shift tower body that raises the pivot point of the AX15 shifter approximately 1", resulting in about a 30% reduction in shift throw. Click here to learn more

AX15 Rear Bearing Retainer Upgrade (With Hardware)

This billet steel rear bearing retainer plate replaces the weak factory casting on 1985-up AX15 and R151 transmissions. It helps maintain proper bearing preload and long-term case rigidity.

AX15 1st gear thrust washer Novak upgraded and hardened, includes pin

The AX15’s factory thrust washer is a known wear point under heavy load. Our upgraded hardened chromoly thrust washer helps prevent wear and end-play issues in demanding use.

Also See

• The Novak Guide to the AX15 Transmission
• New, Turn-Key AX15 Transmissions for Jeeps
• AX15 Rebuild Kits & Internal Components