I thought I'd share my thoughts of a shift kit I installed on my Hemi TJ that has the 5 speed auto. This tranny is behind most hemi trucks and durangos.
The stock tranny is smooooth and nice, otherwise mushy!! I wanted my tranny to have firmer shifts and to hold the gears alittle longer on heavy acceleration. I installed a Transgo 545RFE-HD2 kit today. It was suppose to do just that.
After the install the trans is alot firmer and shifts much faster. For the $70.00 kit I would say that its a great deal for what you get. A much improved tranny if thats your thing.
I would say wait until your going to do a tranny oil change. Its not worth wasting clean tranny oil doing the installation. I was bored and I did it anyway. I was able to recover most of the oil. It was super easy to install. Took me about 1 hour.
Before when accelerating, the auto would shift early and slow. Now its fast and firm. 3rd to 4th is also way better and holds the gear longer. My TJ is really really fun to drive around and now its much better.