It sounds like your TC was too far gone, from the slipping, and it has started slipping again. I know that "Mercman" has stated that any TC slipage will kill the friction material within the TC.
RedCoat999 - The overheating issue is a very well documented problem in the CD4E's valve body piston design. The bores wear out and will cause the piston to hang inside the bore. The most common to wear, like this, is the piston that controls the cooler flow. And by cutting off this flow, it doesn't take very long for the fluid to get boiling hot. Once this happens, not only does it cause harm to the clutches and the like - but it also increases the wear in the other bores of the valve body as well.
Why does this happen with only the CD4E? Well, that is a two part answer that splits both ways actually.
1) It is not just related with the CD4E. All automatics have a somewhat similar problem.
See, as the pistons move back and forth in the bores, it actually hollowes out two seperate sections within the bore. Most of the time, the bores with wear unevenly. Don't ask me why, they just do. And this will cause the side of the piston that is seated in the widest opening to fall. This in turn will cause the piston to "stick", because the piston is no longer sitting in the bore perfectly straight.
If the bore wears evenly, the piston will actually float within the bore and this causes leakage. When this happens the piston could be slow to actuate, when the hydraulic pressure is applied to it, or not even move at all.
So, as you can see, this is a very common problem. And this is not just in transmissions. This same problem can be found in all types of air cylinders as well as magnetic actuators (which I used to see a lot of in my feild of copier/printer repair).
2) Well, whoever designed the pistons did not do a very good job. I'm not real sure what they were thinking. I'm betting it was one of those enginnering meets that went something like this...
Design team coordinator walks in the conference room, where awaiting him are three engineers with their ideas of the hydraulic circuit for the new CD4E transaxle...
"What do you have for me today?" He hears a quiet giggle from his co-workers.
"Yeah! Check this out! Wait until the mechanics get a load of this." This comment was followed by a slightly louder giggle from the engineers.
With an amused look on his face, the team coordinator says, "They will never know what hit'em!" Laughing out loud he excliams, "Send it over to production boys!".Or something like that anyway.
