Hi Folks, very long time and no post!

Wondering if anyone has seen / had / diagnosed a root cause for these symptoms:
1998 Chevy Blazer, 178K miles, 4wd.

About a year ago, the transmission started slipping under power on a 15 mile trip, and after some rest and a little added trans fluid, it behaved normally until it seemingly stopped shifting at all. Prior to that day it was behaving normally for it's age. After it was towed and sat for a year, I discovered:

If you start it up and put it in gear, it will move forward almost normally for a couple feet, then, you shift it into reverse, and it will move backward normally for a couple feet. After a few feet and iterations of forward and reverse, it's done.
- If you shut down the engine and wait 30 seconds before starting it up, it will move again for a few feet in forward and reverse before it fails to move at all.
- The trans fluid isn't new, but doesn't appear low.

To me, it seems like it's pumping fluid, and the torque converter is working, but that it's either:
1. Plugging up somewhere and building pressure which dissipates when the engine is shut down.
2. Pumping, but running out of fluid somewhere in the system, starving components until the engine shuts down.

Does this sound like a problem that a fluid / filter change could resolve, or does it sound more like a torque converter / pump issue?

Thanks for your time and input!
-Louis

 

There are some good videos out there that you might look at. Search for 4L60E problems, e.g. .