I have a rebuilt 99 Grand Cherokee Laredo 4.0 42re transmission . Want to replace my 98 Grand Cherokee Laredo 4.0 42re transmission with it. The info that I got is, they are not interchangeable.
However side by side they are identical. What is the difference?

 

Found the answer to my problem. The 1999 and 2000 Grand Cherokee 42re are the same as the 96,97 and 98. The difference is the electronics. You could use a 99 and 2000 42re on a 96,97 and 98 as long as you use the 96,97 and 98 electronics. The shifting is different on the 99 and 2000.

 

Why are you condemning the first transmission? Biggest issue I found with the RE is the throttle cable adjustment. Everyone wants to tighten it up waaay too much and it just wont shift right if you don't do it from underneath. You MUST go under and verify that , at stop, the cable lets the lever on the transmission go ALL the way back. NO play. All the way to rest.

 

The overdrive was a total lost. The cost of the OD was almost the same as the rebuilt transmission.

 

Also the vehicle speed sensors are different. They are internal to the transmission and not in the t/case like the earlier ones. Everything is on a data bus system in the WJ. Data on vehicle speed is sent to the PCM and THEN sent to the speedometer in the dash. There's no direct link from any of the sensors to the gauges either. Oh yeah! and the rear ABS sensors are used to compute vehicle speed as well!

Loss of O/D may be just a broken snap ring. In order to find out, downshift and see if you have engine braking. If not, that's the problem. It can be fixed if caught early, but there's a 600 lb spring in the unit that is held in by that snap ring and it's nothing to mess with without an arbor press.

 

Hey guys, I'm new to the forum and didn't want to immediately start up a new thread and this was the most relevant one I could find. I have a 99' Laredo that's in great condition other than the transmission and I want it to be my son's first vehicle. That being said, I've been looking all over the East Tennessee area and can't seem to find a good used 42re anywhere. I found this rebuilt 42re for about 1700 bucks, https://reman-transmission.com/trans...des/?code=42RE, which isn't a horrible price but not sure if I can put myself shell out that much on a vehicle with 173,000 miles lol. My question is where did you get your rebuilt 42re and how much did you pay? Any recommendations would be appreciated