TH350 won't shift to 3rd at WOT
 

Tranny works fine other than the shift from 2-3 at WOT. 1-2 shift at WOT feels fine....shifts at what sounds like about 5k rpms in D. However, if you stay in the throttle after it shifts to 2nd it just keeps revving higher and higher in 2nd. I keep waiting for it to shift to 3rd cause it is screaming! I'm guessing at least 6k rpm with no shift to 3rd (it's a basic Gen 1 SBC, so 6k rpm is pretty high)). Eventually i have to let off cause I don't have a tach and I'm afraid ill float the valves.

The strange thing is that if I barely let off the gas while WOT (still giving it probably 7/8 throttle) in 2nd it will shift to 3rd just fine. Any ideas?

Anyone? I know the governor takes over for wide open throttle upshifts. What has me stumped is if this indeed is a governor issue, wouldn't the 1-2 upshift fail to happen too?