How to change the Fluid and Filter in a Jeep Cherokee AW4 transmission

How to change the Fluid and Filter in a Jeep Cherokee AW4 transmission

My Cherokee was long overdue for a fluid and filter change. While I have changed the filter for many others I have neglected my own for far too long. I finally decided to remedy that and with over 360,000 miles on the odometer, I finally decided to open the case.

The transmission pan has the dip tube attached to it. Ideally, you can leave the dip tube attached to the bell housing and just remove the pan. This seldom works for me. So before I lifted the Jeep, I removed the 13mm headed bolt that holds the dip tube to the bell housing.

I continued by supporting the transfer case on a stand and removing the cross member. The transmission mount is held in place by for nuts with 13mm heads. A deep socket is helpful to get them loose. Then the cross member is held to eh body by four 15mm fasteners. While it appears you can get to the back bolts with the cross member in place, you really can’t and it saves time overall to just remove the cross member.

Next I removed the drain plug and let the oil fluid drain out. It was pretty dark but looked OK.

I then used a wire brush and a scraper to remove years of dirt and mud off the pan bolts. It took a while to find them all. While cleaning, I took the new gasket out of the box and laid it in the sun and set some weights on it to try to flatten in out. It was pretty wrinkled in the box.

Once I found all the bolts, I counted the holes in the new gasket to know how many I was looking for; I removed them with a 10mm socket. I had to pry the pan gently away for then bottom of the transmission. As usual, I bent on corner before it separated from the sealant.

With the pan loose, I twisted the dip tube around to allow the clip to clear the bell housing and removed it as a unit. Once it was on the floor, I was able to pull the pipe out.

Next I removed the bolts that held the filter in place and carefully removed it. The old gasket stuck to the transmission so I had to scrape it off. It inspected the old filter and lit looked fairly clean. I installed the new filter with the original bolts.

I removed and cleaned the two magnets in the pan. There was very little metal on them. Not bad at all for 360,000 miles. After wiping out the pan, I took it to the anvil and straightened the corner I bent getting it loose. I then used a wire brush to clean the remainder of the old sealant off the pan.

I used a scraper to clean the bottom of the transmission. I then replaced the magnets in the pan. I slid the dip tube up into its approximate position. I then had to use a heat gun to get the gasket flat enough to work with. I started four bolts in to the pan to hold the corners of the gasket in place.

I then started all the bolts before running any of them down. I had to wiggle the pan around some to get all the gasket holes to line up properly. Once they were all in place, I tightened them gently to compress the gasket evenly. I then set the dip tune in place and pushed it down as best I could from below. I reinstalled the drain plug and cross member. After lowering the Jeep, I pushed the dip tube fully into place and bolted it back to the bell housing.

I then added a gallon of Dextron ATF fluid and started the engine. Finding no leaks, I let it warm up a while and re checked the level. It was just about right.

I was disappointed that the slight hesitation I had when cold was not corrected by the fluid and filter change however. Even after a week of driving with fresh fluid, it still too a few extra seconds to engage reverse on cold mornings.

On the advice of a mechanic friend, I added a bottle of Trans X to the fluid. I have always been very reluctant to try to solve performance issues with chemicals but he assured it me it would do no harm to try. So I poured it in and hoped for the best.

After a few days the transmission was back to its old self with no more hesitation on cold mornings. Hopefully it was just a sticky spot and all will be well for another 100,000 miles or so.