well some of you have seen my car and specs on the engine gears converter and trans......well It's a C6 rebuilt.....problem is it shifts early........1/2 2/3 when I stab the throttle it shifts at 4400 rpm in drive light throttle 1/2 2/3 shift before I cross intersection before I hit 2000rpm. If I hold it in 1st gear it shifts by itself to 2 and 3 I always thought if you hold 1st it stays in 1st......2nd and so on any Ideas? Thank you
Other than internal problems it could be that the modulator vacuum line connected to ported carb vacuum instead of direct manifold vacuum if it calls for that. Bad or leaking vac line. The modulator is bad. Some modulators have a screw on the outside or a tiny screw inside the hose fitting to adjust them. Most auto trannies, from back then at least, will upshift eventually when you accelerate beyond a certain point even if you leave them in first.
BlueVista covered it all. I'd start at the kickdown linkage adjustments, after checking if the vacuum line is snug to the modulator, maybe pickup another one at a junkyard and try it, before you get into the guts of tranny adjustments.
Check the kickdown cable length and adjustment while you are at it. It light be on a short setting. Though being that old, it probably has the slide connector on the throttle arm, newer ones have an adjustable coupler on a bracket. Too short will cause it to shift late, to long will cause it to shift early.
Thanks guys I've tried all that and some but nothing......I've had a few C6 equipped cars over the years and never had this problem before. If I keep the car in first it stays in first.........manual shifting it this one won't stay.........
Maybe someone over here can help: http://www.network54.com/Forum/260730/ There was this post: http://www.network54.com/Forum/260730/message/1253240878/1974+C6+shifting+too+soon
Have the Toronto area tranny shops improved since 1975 (last time I was there)? Sounds like you need the possum inerds fixed. The old girl needs a wiggle in her walk. Hate to be the bearer of bad news. It can run up to $1,200 or more. Check the Buy and Sell or AutoTraders for one. Andy and I got new ring gears welded onto our torque converters (they rebuilt them too) and we asked about rebuilding costs for our C4's. Just the valve core was $700, if he could find one. Then there's all the other replacement parts. The converter alone was $150 with the ring gear on. Probably pick up a running parts car for a lot less.
what year is the tranny?....you may have a 1st gen C6...yano...like a cruise a matic...2nd is 1st...1st is 2nd....just thunkin.. ..its too early to think big
not sure what year it was came out of my race car.....all I did was swap housings small block to big block....
I know it's been a problem for a while.......funny thing is sometimes it works great........but most times it doesn't.
PMS Post Motor Syndrome. The tranny wants to be in front of the motor. Weird set of symptoms, for sure.
