The 1999 Jeep Wrangler TJ offered two main transmission options: a five-speed manual and a four-speed automatic, depending on the engine and trim.
Context for the era: The TJ generation (1997–2006) refined Wrangler powertrains with a modernized manual gearbox and a reliable four-speed automatic. For the 1999 model year, manual gearboxes were paired with the two available engines, while the automatic option was offered on several trims as an alternative to the manual.
Manual transmissions in the 1999 Wrangler
Two manual configurations were commonly used, chosen to match the engine options available in the 1999 TJ:
- AX-5: A 5-speed manual typically paired with the 2.5-liter four-cylinder engine.
- AX-15: A 5-speed manual typically paired with the 4.0-liter inline-six engine.
Conclusion: In 1999 Wranglers with manual transmissions, the AX-5 or AX-15 were the standard options, selected based on engine choice.
Automatic transmissions in the 1999 Wrangler
The automatic option for the 1999 Wrangler was a four-speed unit used across many trims, most commonly associated with the 4.0-liter engine but also available with certain configurations of the 2.5-liter engine through optional packages.
- 4-speed automatic (commonly the 42RLE): The standard automatic transmission for many 1999 Wranglers.
Conclusion: The automatic transmission configuration for the 1999 Wrangler TJ was a four-speed unit (42RLE), paired with the appropriate engine and trim level.
How to identify your transmission
To confirm which transmission your specific 1999 Wrangler has, check the vehicle’s documentation, look for the transmission code on the bell housing or trans case, or consult a Jeep dealer or service history. The shifter layout can also help: a manual stick indicates AX-5/AX-15, while a PRNDL-style lever indicates an automatic (likely 42RLE).
Summary
The 1999 Jeep Wrangler TJ offered two broad transmission paths: a five-speed manual (AX-5 with the 2.5L engine or AX-15 with the 4.0L engine) and a four-speed automatic (42RLE). The exact configuration depended on engine and trim, so checking documentation or the vehicle itself is the best way to confirm.