C-6 question about pre-mature shifting

Last time at the strip, my essentially stock vb C-6, while still in manual low, did a "way early" 1-2 shift. Linkeage is adjusted correctly. Ideas? Running behind a ~550 hp. BBF in a drag race application.

Thanks,
Greg C.

I have the same problem right now. The last time this happened I put a new shifter cable on and everything was great....for a few years.

I use the Hurst Promatic on both T-Birds, but I am thinking of going to a nicer rear exit (for the cable) shifter because the Promatics are front exit cables and I think the cables are in too tight of a bind and that is what is causing the trouble.

I have had this problem before, and it turned out to be the manual valve adjustment inside the trans.

What was happening was that the detent spring was mis adjusted, and the manual valve was in the wrong position while in the 1st gear detent.

This ended up killing my trans.

I don't have the spec sheet in front of me, but there are dimensions and measurements taken in each detent and then adjustments are made to the detent assembly to properly position the manual valve.

Greg

Thanks. My next stop is checking cable adjustment vs. shift valve location. Anything is possible...

Thanks for the input.

Greg C.