you know...the info posted above does say that the "B" solenoid will have the same symptoms...
I wonder if its worth trying before pulling the tranny?

 

can these solenoids go out W/O throwing a code?

 

I guess I'll pull the pan tonight and see if its full of clutch material...
if not, I'll pull the solenoids out of my old tranny or get a couple new ones...

 

Ifits a solenoid it will simply not upshift if its the 3-4 clutch pack it will shift 1-2 and then where third should be will feel like neutral

 

Sounds to me like a simple case of the 3-4 clutch's failing. The odd part it that they shouldn't have been failing at your power level that quick. How was it shifting when you first put it in?

 

shifted great, 1-2, 2-3 & 3-4...
drive it to work 7 days a week...
been to the track 3 times with it...new best each time...
then several hours into running errands in town w/o any issues at all one day, a week or so ago, it started acting up on 2-3...same next day...no 3-4 the following day...

 

The 3-4 clutch pack and 2-4 band can be the problem? Look at the valve body, chips or debris can plug the orifice of the 2-3 shift solenoid. This will cause the trans to stay in 2nd gear longer at times when 3rd gear is requested. 2-3 shift valve or 2-3 shuttle valve that is sticking of hung-up due to debris can be a cause? The debris can be a indication of a damaged 2-4 band or 3-4 clutches? Hope this helps?

 

planning on pulling tranny tomorrow night...

 

A solenoid isn't going to fix your problem, That is a GM bulletin to address a flare condition on take-offs. You have a burnt 3-4 clutch pack, either due to excessive clearance or low line pressure due to a pressure loss. I always set my 3-4's up with 8 blue plate clutches and kolene steels.

 

yeah, I'm thinking clutches too...
we'll see in a day or two...when they crack it open...