2000 Jeep Grand Cherokee Transmission Fluid: What Type to Use
The Short Answer
The 2000 Jeep Grand Cherokee belongs to the WJ generation, sold from the 1999 through 2004 model years. Both automatic transmissions offered that year are serviced with Mopar ATF+4, Chrysler's automatic transmission fluid specification. ATF+4 is a synthetic-based fluid that Chrysler introduced to replace its earlier ATF+3 and ATF+2 specifications. Chrysler's service guidance says ATF+4 can be used in transmissions that originally called for those older fluids.
Why the Transmission Matters
The fluid type is the same for both automatics, but the transmission behind the engine affects the service procedure and how much fluid is needed. For the 2000 model year, the pairings were:
4.0-liter inline six: 42RE, a four-speed automatic derived from Chrysler's older hydraulically controlled designs, with electronic governor and overdrive control. 4.7-liter V8: 545RFE, a fully electronically controlled automatic that was new for the WJ. It has five forward gear ratios in normal use.
If you are not sure which engine your Jeep has, check the vehicle identification number (VIN), the underhood emissions label or the engine itself. You can also look for an identification tag on the transmission case. Confirm the transmission before buying parts such as a filter or pan gasket, because these differ between the two units.
About Older ATF+3 References
Some printed materials and older parts-store listings for WJ-era Jeeps mention ATF+3, especially for the 42RE. ATF+3 has since been superseded. ATF+4 is the fluid Chrysler currently specifies for these transmissions, and it is the one you will find stocked under the Mopar name. For the 545RFE, ATF+4 is the required fluid. Do not substitute Dexron, Mercon or other non-Chrysler fluids.
Using Non-Mopar Fluids
Several aftermarket brands sell fluid labeled as suitable for ATF+4 applications, as do universal multi-vehicle ATFs that claim to be compatible. These claims come from the fluid makers, not from Chrysler. Whether a given product performs the same as genuine ATF+4 is outside the scope of this guide. Choosing Mopar ATF+4, or a fluid that is officially licensed to the ATF+4 specification, is the more conservative option, especially for the electronically controlled 545RFE.
What This Guide Does Not Cover
This guide does not list fill capacities, service intervals or the fluid-level check procedure for either transmission. Those figures depend on the transmission and on whether you are doing a pan-drop service or refilling after an overhaul, and no verified values were available for this article. Use the owner's manual or the factory service manual for your Jeep's transmission. The transfer case on four-wheel-drive models is a separate component with its own fluid requirement, which varies by transfer case model, so do not assume it takes the same fluid as the transmission.