Jeep Wrangler JK: How to Change Manual Transmission Fluid

Changing the transmission fluid on your Jeep JK is a quick and simple procedure you can do at home. This article explains how to do so.

By Neftali Medina - December 2, 2015
Contributors: GPT Adventure Channel

This article applies to the Jeep Wrangler JK (2007-Present).

Are you experiencing any sluggish or hard shifting? It sounds like it's about time to check and change your transmission fluid. Just like oil does for an engine, transmission fluid is responsible for keeping the inside of the gearbox lubricated. Overtime, the fluid's consistency will begin to change, becoming too dirty and lacking additives to provide enough lubrication on the transmission's internals. To avoid this issue, Jeep recommends the fluid be changed every 30,000 miles.

Materials Needed

  • 3 quarts of Mopar MS-9224 manual transmission fluid
  • 17mm wrench
  • Oil catch pan
  • Bottle pump
  • Cut H17 Allen key bit
  • Bench vise
  • Die grinder
  • Sawzall with steel blade

Step 1 – Make custom Allen key bit

The drain plug for your transmission is actually located an inch above the exhaust pipes. This makes loosening it a difficult task, unless you have a special tool for the job. The following instructions explain how to quickly make such a tool.

  • Take a 17mm Allen key bit and place it securely into a vice.
  • Measure approximately half an inch of the bit and cut the rest off using a sawzall.
  • Grind the edges of the bit (optional).
Figure 1. Cut the 17mm Allen key bit.

Step 2 – Place a drain pan under the transmission

Old transmission fluid is a terrible mess to clean up, so let's make it a point to avoid any unnecessary spill-ups. Place a drain pain directly under the transmission and place a rag on top of the exhaust pipe.

Figure 2. Cover the top of the exhaust pipe.

Step 3 – Drain the transmission fluid

Loosen both the fill and drain bolts. The fill bolt is found on the passenger's side of the transmission, and requires a 17mm Allen key bit to be removed. For the drain bolt, take your newly created 1/2 inch Allen key bit, insert it into the socket and use a 17mm wrench to loosen it. Once off, let the fluid drain into the oil pan.

Figure 3. Drain the transmission fluid.

Step 4 – Refill the transmission fluid

  • Install and tighten the drain bolt.
  • Take the bottle pump and place the line into the fill port.
  • Pump two quarts of transmission fluid into the casing.
  • Install and tighten the fill bolt.
Figure 4. Pump new fluid into the transmission.

Featured Video: How to Change Manual Transmission Fluid in Jeep JK

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