c6 shifting strange !!

[rbjb99]

Hi, I'm new to the site and am hoping someone can help me.

I have a 73 351c c6 all stock, just finished rebuilding the car and when I drive the car if I put it straight into drive and go, it wont shift until the car is screaming up the road, if i put the car in 1st then move it up to drive it changes up and down perfectly all day long.
I don't have to shift it manually, just down into 1st then up to drive and its ok.
If i stop and put it in park then straight down to drive it will shift weird again.

Anyone had this problem?? I thought it may be the modulator but why does it shift right one way and not the other???

Thanks for any help.

Rod

 

[stonecoldtx]

Hi, I'm new to the site and am hoping someone can help me.

I have a 73 351c c6 all stock, just finished rebuilding the car and when I drive the car if I put it straight into drive and go, it wont shift until the car is screaming up the road, if i put the car in 1st then move it up to drive it changes up and down perfectly all day long.
I don't have to shift it manually, just down into 1st then up to drive and its ok.
If i stop and put it in park then straight down to drive it will shift weird again.

Anyone had this problem?? I thought it may be the modulator but why does it shift right one way and not the other???

Thanks for any help.

Rod

What exactly did "rebuilding the car" encompass? Did you do any work on the transmission?

 

[D.Hearne]

Go to your local Advance Auto Parts. There in the transmission additives shelf you'll find a bottle of Lucas Transmission Treatment. Buy a bottle and pour it into the C-6. Problem solved after about two laps around the block.

 

[rbjb99]

will give it a try, thanks for the help

 

[D.Hearne]

It's probably gummed up from sitting too much. That stuff cleans the gum off the valve body parts. I've used it in an E4OD that was acting up and a 62,000 mile C-6 that was 38 years old (and never rebuilt) It worked on both transmissions. The C-6 was doing the same thing yours was.