trans slipping from 2nd to 3rd

[Tyrant]

no matter what temp how long i run the truck if the tc is locked up or not.....my trans slips from 2nd to 3rd at wot.....does anyone have any ideas what this could be.......it been in the trans shop like 5 times and they cant figure it out.......could the wrong valve body be the cause of this????

thanx in advance
Jake aka "OREO"
92 TY

 

[jwaller]

yes its possible, so are about 10 other things. if its been back that many times they obviously dont know what they are doing. check to make sure the correct boost valve was installed. this could be the most likly culprit. so could the wrong accum springs. wrong clutches, not enough clutches, and on and on.