5R55W Performance Issues

[Mercy]

Need help with a diagnosis or advice about what to do with my transmission. 03 AWD with 145K. The fluid has never been flushed.

The other day, at highway speeds, I went WOT and my Overdrive Light started flashing and the cluster said Check Transmission. Haven't had time to scan the code but when I got home I tested it out some more. Here's what I got:

From a stop, at medium acceleration, the first shift starts to take place at 30mph but is delayed and the rpm steadily rises to 5k and then the vehicle will shift. While the rpms are going up, the vehicle is going faster so it doesn't feel like a common "slip." Only seems to do it when the fluid is hot, okay when cold and the delay is not so noticeable when I accelerate lightly. The other 2-3 and 3-4 shifts are okay. Not sure about 5th.

I've done a ton of reading on the Servos, Valve Body and Solenoid Block. It seems like the Overdrive Servo is suspect and fluid has been leaking past the bore. I bought the vehicle with 100K on it and the shifting has never felt firm, just lazy. Is there anything that stands out? Also, are there any great tranny rebuild manuals. I do have AllData Pro but the layout for the rebuilds aren't easy to follow.

 

[swetrid]

You should have a 5R55S trans an I definitely think the overdrive servo piston is bad. You can do it in the car if you try hard enough but it isnt easy.

 

[plasticseng]

I have this manual and it is very thorough and well illustrated.

http://www.transmissionpartsusa.com/5R55S_W_transmission_repair_manual_2002_on_p/230-00023tm05.htm

 

[Mercy]

After giving much thought, it would probably be wise to just remove the transmission from the vehicle and work with it outside the vehicle. I'd hate to remove the servos while the transmission is still in and find out that the bores are faulty. All this talk on here about replacing just the servos themselves but what about the bores? Are they checking them?

So this article and am convinced I should do it right the first time, fluid is expensive too!

 

[justchecking]

I had a similar problem and had the valve body/servos updated by the local trans shop ($700) and it's been good for the last two years...