400 tranny shifting funny

well i did it and put a bm shift improver in the t bucket before last race seemed to work good shifted well etc.
near the end of the day it started to shift kind of funny , i was leaving it in drive to race and it would come out of the hole good, my car had some wheelspin and the car would suddenly shift into 2nd gear just after it started to hook and then shift back down into 1st and run the normal shift cycle.
it does not do it when it is shifted manualy 1-2-3
any ideas, i may have buggered something with the shift kit? but i would think maybe the modulator is going bad causing the engine to think i am letting off.
just a thought.
any ideas out there:confused: :confused: :confused: :confused: :confused:

those check balls in the valve body are they rubber ? becausewiyh the higher pressures involved with a hift kit the rubbers could be jamming in the seperator plate. All good rebuilds replacements have steel check balls

Had a similar problem with a 727 trans when we put a shift kit in, it shifted wierd in "D". Turned out we'd left a ball in one place, where it was supposed to be omitted. It kinda made the operation of the shifting a totally random thing, depending on where the ball bounced to in the cavity. Drove us nuts for days!

Hey canadianal, how is the drag racing coming otherwise? Awhile back you were looking for ways to shave some et, how did that work out?


Don

well the balls are steel and i must have put them in the right spot as the trannyworked fine for most of the day. it shifts fine as long as your not on it but as soon as you romp on it and spin the tires it seems to do the funny up and down. i am going to get a adjustable modulator to see if its the problem. i cant expect much the tranny came out of a 71 olds and i am shure it had never been rebuilt.
got the bucket down to a best of 13.9 late in the daywith just tightening up the rear traction bars, loosening the front sway bar and bumped the timimg ahead about 5 degrees. the timing was the big thing as the car hits like a bag of hammers off the line now with a stock convertor . i did pretty good in the king of the hill dialed in at 14 seconds and and even ran once right on the dial in, i red lit against a truck i previously failed in tech that day,he had 2 boken rear studs and a lug nut missing. me being the nice guy told him to get his butt in gear and get some studs and change them and hussle back and i would pass him. he got it fixed and of course i have to end up going against him. not bad though for a 2nd race ever and lots of more experienced racers there.