Noticed the transmission was having a hard 3-4 upshift and some very mild shudder in 1st and 2nd gear. All other gears and TC lockup felt very smooth. The transmission did not give any codes or CEL. Did a cooler line flush about 15k mi ago and fluid was still in good condition. Found that these gen1 units have pressure switches in the TECHM with thin plastic disks that blow out and can cause issues. Repairing them takes removal of the valve body/TECHM cover and removal of the TECHM, and the tools + disks and grommets are $15 in parts. Did the job this weekend and found 2 of 4 switches were blown out, so I replaced them all. It certainly did not hurt the operation of the transmission, but the 3-4 shift is still a little hard although seems improved/improving. We'll see after the transmission fully adapts as it should be going through an adaptation after the TECHM was disconnected.
Here's a picture of the blown switches in mine:
Here's a video of the pressure switch service:
Here's a picture of the blown switches in mine:
Here's a video of the pressure switch service:
