Mine tends to do the same thing. Slee refers to it as flaring. According to Cristo and Robbie some trucks develop this problem and do it for 100K with no further problems. Ive messed around with the cables and tightened them to no avail on my rig. Probably gonna have to get an extreme valve body from Rodney or an entire new tranny eventually but I'm gonna run the guts out of this one till then.