Manual Transmission Swap Parts Guide

This guide outlines all necessary parts to swap your 1984-2001 Jeep Cherokee XJ or 1986-1992 Comanche MJ with 4.0L inline-6 engine from an automatic transmission to a manual transmission.  The easiest way to accomplish this is by buying a wrecked donor vehicle with manual transmission and swapping over everything from behind the engine, however there are some smaller parts that are required or you may wish to upgrade some of the components.

Overview of Required Parts

  • Aisin AX15 5-speed Transmission
  • Flywheel, Clutch, Pressure Plate, Pilot Bearing
  • Master Cylinder, Hydraulic Lines, Slave Cylinder, Throw-out Bearing
  • Pedals, Shifter, Tunnel Cover, Shifter Bezel
  • Transfer case (if converting to 4WD)
  • Front and Rear Driveshafts
  • Intermediate Mount Plate and (optionally) Crossmember
  • ECU (depending on year and CEL)

Installation

  • This is not meant to be a guide for installation, however the high-level process is to remove everything from your vehicle from the engine-back, including the flex plate, transmission, cooler & lines, transfer case, crossmember, drive shafts, and automatic shifter.  All removed parts are then replaced with their corresponding manual transmission components.  There are numerous videos on Youtube outlining this process in more detail.

Caveats & Gotcha's

  • There are numerous years that the AX15 transmission was available.  It came with an internal and external slave cylinder bellhousing.  We strongly recommend using the external slave cylinder bellhousing (which can be swapped to a internal slave AX15).
  • Do not mix up an AX4/5 with AX15.  They look similar but the AX4/5 have a steel mid plate.  The Peugot BA5/10 is also a terrible transmission--do not consider using this.  The NV3550 transmission is similar to AX15 and a viable option (although transfer case input shafts are different lengths).  The Jeep TJ NSG370 6-speed transmission has a lower first gear ratio, but is not easy to source and anecdotally unreliable.
  • 2WD and 4WD AX15 transmissions are not interchangeable.  Do not buy a 2WD transmission if you plan to go 4WD.
  • AX15 has a 23-spline output shaft.  This must be mated to a NP231 or NP242 with 23-spline input shaft.  If you have a pre-1990 transfer case with 21-spline input, you can rebuild it and upgrade to 23-spline.

Detailed Parts List & Sources

  • AX15 Transmission: We suggest buying new from Novak unless you have a known good donor.  If you purchase a used transmission, try to find a 1994-1999 model from XJ, YJ, or TJ which will include the external slave cylinder bellhousing.  P/N 52108118AB
  • Bellhousing-to-Engine Torx Elimination Kit (optional): Mopar J0180129
  • Transmission Dust Cover: This is a thin aluminum part that covers the flywheel and lower half of the bellhousing.  Source from eBay or junkyard.  P/N 004-473
  • Master Cylinder, Hydraulic Hose, Slave Cylinder: We recommend external slave with sealed, pre-bled system.  AMS PS0112 Kit
  • Flywheel: There are two versions that are not interchangeable:
  • Flywheel-to-Crankshaft Bolts: ARP (146-2801)
  • Flywheel-to-Pressure Plate Bolts: Mopar J4004165
  • Pilot Bearing:
    • 4.0L/4.2L Crankshaft (3/4" ID, 1.0" OD): SCE1295
  • Pilot Bearing "Donut" (not needed for some crankshafts): FC69907
  • Clutch Kit (clutch, pressure plate, throwout bearing, alignment tool): LuK RepSet 05-901
  • Bellhousing-to-Transmission Bolts (#1 below): Mopar 6503299
  • Clutch Fork (#2 below): Mopar 52107555
  • Clutch Release Spring (#3 below): Mopar 4338855
  • Clutch Fork Release Pivot (#4 below): Mopar 52087542
  • Clutch Pedals: Purchase used based on generation from eBay or junkyard (1984-1996 or 1997-2001).
  • Transmission Mount Plate w/ Exhaust Bracket: Purchase used from eBay or junkyard.  Note--Year range is approximately 1984-1999.  ~2000+ has a different mount type.  Not interchangeable with automatic transmission.
  • Transmission Rubber Mount: Mopar 52001180 
  • Transmission Crossmember: There is a 3/4" drop built into the manual transmission crossmember.  You may be able to keep the automatic crossmember if you run an SYE or have moderate driveshaft angles.
  • Transmission Tunnel Cover: Adapted Mopar 53000704 which allows for TJ lower shift boot Mopar 52078970
  • Upper Shifter Boot & Retaining Bezel:  This is for a TJ, but can be adapted for XJ.  52078558 and 53000056 
  • Transfer Case Slip Yoke Eliminator (Optional): NP231 SYE
  • Transfer Case Rebuild Kit (Optional): NP231 Rebuild Kit
  • Transfer Case Shifter: Improved Geometry
  • Driveshafts: While you may be able to swap these from the donor vehicle, keep in mind that the length varies based on axle type, transmission, and bed length (for MJ).  If you are doing an SYE, a custom rear CV drive shaft is required.  The automatic front drive shaft is approximately 1.5" longer than a manual transmission driveshaft and may work for lifted applications.
  • ECU: The automatic transmission ECU will work for all years, however there will be issues with missing upshift light (on older years), cruise control, idling issues, and CEL on 1996+.  Best to swap if you can.
  • Reverse Light Pigtail: 2-Pin Connector
  • Gear Oil: 75W90 GL-3
  • (Optional Replacement) Transmission Dust Cover: 83500520
  • (Optional Replacement) Transmission Shift Bushing: 18886.86

 

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