Just picked up a 93 150 w/4.9L and E4OD. Went over the codes and found that the epc solenoid was bad. The truck was shifting hard so i figured it was an easy fix. Replaced the solenoid pack, changed the fluid and filter and really made sure the harness and connectors were in good shape. Truck runs and shifts through gears great.
The problem is i'm getting a code 628 excessive converter clutch slippage. The only symptom is a shudder when i'm in gear and stopped, doesn't occur when i'm at speed and only occurs after trucks been driven for a few miles and really warmed up.
I don't know the first thing about transmissions so i could use some help.
Befor i go writing off the converter i'd like check out some other ideas. A buddy of mine whos a ford mech said it could be # of things that set the code off.
1) He said an off vss could trip the code. I've got 31's on the truck so could that be throwing off the speed sensor?
2) Severely high or low line pressure could cause slippage and trip the code.The code wasn't present when the epc was bad and line pressure was at max. Is there a way to check the line pressure now the solenoids fixed and pressure should be normal?

The bum left for vacation today and i can't get anymore info out of him. Anyone have suggestions as to what else i could look at.