4L80E gremlin, replace shift solenoids?

[Calvinator]

Hi all -

Still working on some gremlins in my new-to-me 1995 Suburban 2500 350TBI OBDI 4L80E w/68k miles.

I get hard shift from Park-Reverse and Reverse-Forward. Shift from 1-2 seems delayed and hard. Shifts from 2-3 are OK. Downshifts are sometimes jerky.

And this does not happen all the time.....30% of the time shifting is nice and smooth and the Sub is a pleasure to drive.

I've been troubleshooting the PCM and sensors. All good here and I have no codes. I also threw $40 at the problem and replaced TPS and IAC with fresh Delphi parts. No luck.

So now I am focusing on the transmission shift solenoids and how they work. There is a speed sensor in there too. Before I get too far, anyone have hard shift problems like I do and it was the shift solenoids ?

THANKS

 

[rhino]

Sounds like something has the pressure maxed out. If you have a scanneer that shows data, look at the pressure control solenoid and watch the amps. Should be around 1.5-2.0 at idle. 5.0 is max. A ton of sensor's can cause this. Any codes at all?