Jeep Wrangler automatic transmission fluid and filter change

My 2005 Jeep Wrangler has about 66,000 miles on it at the time of this writing, far past the recommended time to change the automatic transmission fluid and filter. The 4-Speed 42RLE automatic transmission that came on my model year is not known as a very reliable transmission, since it’s prone to early failures. You can get a lot of extra life just by changing the fluid in your 42RLE transmission. It turns out that I didn’t need to put off changing it, because it’s a pretty straight forward process that can be done In about 2 to 3 hours for your first time.

The overall process is pretty straight forward:
1. Remove the transmission skid plate.
2. Remove all the bolts around the transmission pan and drop the pan, trying not to get ATF everywhere
3. Replace the transmission filter with a new one
4. Bolt the pan back on
5. Fill the transmission back up with ATF


Parts needed
Transmission filter kit - $31.48 (Advanced Auto Parts)
Castrol ATF+4 (6 quarts) - $35.94 (Advanced Auto Parts)


So, why change the ATF in your Wrangler?
The primary cause for automatic transmission failure is due to heat. Most ATF is designed to run at 175 degrees F. At this temperature most ATF will last at least 100,000 miles - the problem is that for every increase of 20 degrees above 175 the life span of the ATF is cut in half. That means that at 195 F the ATF will last 50,000 - at 215 F (which is commonly seen in many transmissions) the life span is only 25,000 miles.

When the transmission fluid in your Jeep goes bad, it will turn a brownish color, and give off the smell of burnt toast. The only rememdy for burnt or bad transmission fluid is to change it out (there are no additives that can restore bad transmission fluid).