'03 5R55E shuddering during 3-4 and 4-5 shift

[Matt193]

A few months ago I bought a 2003 Ranger with just under 30,000 miles on it. I noticed that when the truck sits for a while and the transmission cools off I will get a hard shift from 3rd into 4th and a shudder while shifting from 4th into 5th. It only does it during a up shift and only when the transmission shifts and locks the torque converter at the same time. After it shifts 3-4 and 4-5 two or three times and the transmission gets warm, it shifts smoothly. If the transmission shifts and then locks the converter when cold, it is completely smooth. All other shifting seems normal.

The fluid is clean and full and for grins I added a bottle of Lube Guard (red bottle) to see if it would help at all. It didn't.

I plan on flushing my trans in the near future when my buddy has a free weekend so we can use the fluid exchanger at his work.

I now have just under 36,000 miles on it and it hasn't gotten worse or improved. Any ideas?

 

[jghake]

Did you ever figure this out? I just bought a 2003 Explorer XLT that is doing the same thing.

 

[Matt193]

No, I haven't had any time to dig deeper into it. I don't have any transmission shops in my area either and I don't trust my local Ford dealer.

Does anyone know if it could be a shift solenoid acting up? What about the torque converter?