Background
At the beginning of this project, my 2001 Jeep Cherokee XJ had about 255,000 miles on the clock. In it, was the factory engine, and a semi rebuilt automatic transmission from one of my parts jeeps. I originally semi rebuilt and installed that transmission due to a P0740 engine code: “Torque Converter Clutch (TCC) Circuit Malfunction”.
Normally, when travelling at >45 MPH, the torque converter locks in order to prevent slippage at highway speeds. This is done by diverting transmission fluid to engage a clutch pack inside of the torque converter via a solenoid. This lockup function keeps the transmission cooler and extends transmission fluid life as opposed to constant slippage. However, when the transmission computer would call for the torque converter to lockup, the lockup clutch would only partially engage, hence the engine code. This creates more heat and burns more transmission fluid than it would otherwise without a lockup system.
To attempt to rectify this, I did fluid changes, replaced transmission solenoids, changed transmission computers, cleaned and rebuilt electrical connectors in and outside of the transmission, and traced bad ground wires to no avail. Finally, I decided to retrieve another automatic transmission and torque converter from one of my parts jeeps. This ‘new’ transmission was rebuilt no more than 10,000 miles before the jeep was parked and had performed well throughout all of them. This also did not fix my issue…
So, the only option left was to get rid of the automatic entirely.
The Parts
There are two distinct revisions within the 1984-2001* (*At least in the US. production ranges vary depending on country since the XJ was manufactured internationally) production of the Jeep XJ. The first major revision was from 1984-1996; with some changes around 1987, coinciding with Chrysler’s acquisition of AMC from Renault. Most notably of these changes is the transition away from the 2.4L inline 4 towards the introduction of the famous 4.0L inline 6. The second range of course is 1997-2001; with some changes in 1998 after the Daimler-Chrysler merger, and primarily electrical and emissions changes (and the move from distributor to coil ignition) between ’99 and ’00 to keep up with American emissions regulations. Very little is interchangeable between the pre and post 97 model ranges. Since I have a 2001 XJ, the year range I can get most parts from is ’97-’01, with the occasional exclusion of the ’97.
There were four manual transmission options for XJs: the Peugeot BA10/5, Asin Warner AX-5, Asin Warner AX-15, and the New Venture Gear NV3550. Both the BA10/5 and the AX-5 were much more common in pre ’97 models, the AX-15 was somewhat constant throughout the XJ production, and the NV3550 was the only option in ’00-’01. The Peugeot is a ‘glass box’ and is out of the question, the AX-5 was only mounted to the 2.5L and is only marginally stronger than the 10/5, the AX-15 is strong and exceedingly common in the 90s AMC/Chrysler lineup, and the NV3550 is directly comparable to the AX-15 but slightly rarer. My choice was the AX-15 over the NV3550, simply for the cost and availability of parts. So, my range for model years was narrowed down to just ’98-’99.
There are two routes in doing the XJ manual swap:
1) Source new and used parts individually, via eBay, junkyards, etc.
or
2) Get a parts Jeep
Less than five percent of all 2.8 million Jeep Cherokee XJs were ever produced as manual. The ’97-’99 manuals are rarer than previous years, and 00′-01′ manuals are rarest. As a consequence, individual parts like the clutch pedal assembly, transmission cross members (which are specific to the manuals), and others come at a great premium when compared to their automatic counterparts. When I priced out the project using route 1, the total was in excess of $5000, which is nearly as much as was paid for the entire Jeep.
As many good things start, I was scrolling on Facebook Marketplace one morning. On there I saw a manual 1998 Jeep Cherokee in abhorrent condition. On it was many a costly upgrade, and what appeared to be a healthy powertrain. It, however, had completely rusted out.
Hey!
This post isnt all the way finished, check back soon for more!