lazy 1-2nd shift driving granny style

[84BuickGNYorkPA]

question for the tranny wizards, my tranny is supposed to be a ckperformance parts filled unit (the seller could not produce a invoice, but his mechanic told me the work was done). I picked it up for $1000 and it's been great for the last yr. no problems, nice firm shift, etc.
Two weeks ago, driving through traffic, I noticed it suddenly had a lazy 1st to 2nd shift, I didn't think much of it. The tranny fluid and filter where changed back about 1500 miles ago when the fresh motor was dropped in.
It really got my attention after my 11.66 run at 116 mph...... after the run pulling out from the time slip shack the tranny was slipping or just not going under normal throttle, as I gave it more rpm's we where moving again, let off the throttle and it seemed to catch. No more passes down the track, drove it home, 1.5 hrs and parked it. On the way home just a lazy 1-2 shift aided by me lifting the throttle to help it shift.
Should I pull the tranny or take it to the Buick Turbo Tranny shop and let them drive the car? I'm thinking just pull the tranny and they can do the rest on the bench.
I wish I knew more about tranny's, never had a problem with them over the yrs. just lately as I move the hp of the motor up.

Chuck

 

[RONNIEDOG]

Granny Style

Wow I have the same problem going on right now. It was fine one day and the next it does not want to shift from 1st to 2nd going to look trany level was a little low but I dont think that was it Im going to replace the filter in a few days and ideas on this would help-its an 87 by the way.

 

[77 cruiser]

If all other shifts are OK I'd lean towards a band or servo issue.

 

[84BuickGNYorkPA]

Ok, sounds like I'll save a couple of bucks and pull the tranny out and take the tranny to the shop, if they don't find anything, I'll send the converter back to Precision Industries. I don't want to drive it like this anyway, I would imagine that I could do more damage to it......
Thanks for the reply's.

Chuck

 

[RONNIEDOG]

Granny style

Ok I just checked the plug and it didnt seem to be in all the way so I cleaned the connection and now I have no reverse and it wont seem to shift out of 2nd Ill look at it more in the A.M.

 

[84BuickGNYorkPA]

Update

Well the tranny was not what I thought it was I took the car to Michael's Transmissions in Waterford NJ and he took it apart to check it out after a road test and pressure gage check. There where no billet parts in the tranny..... none at all. A shift kit and that's about it, maybe aftermarket clutches....
Long story short, it was the anchor pin, busted right out of the band.
I got it back this week, a bunch of billet parts and a new pts converter. Car never shifted so good, just over 20 mpg on the 120 mile drive home, with some stop and go traffic.

Chuck