dugan

my mustang is a bit of a mystery car, and my efforts to find more out about seem to fail. but my question for today is what should a c4 shift at? i ask because mine seems to always shift very low, like 3000 rpms or less, i know the tranny isnt bad b/c i just had it rebuilt.
thanks.

sixt5

at WOT my car would shift at about 4300. thats ALL it had but i think i had a bad converter holing me back. but i fixed it. i yanked it out and thre a 4 speed in there!!!

jlp66stang

First, just because it is rebuilt doesn't necessarily mean anything. Ihad mine built twice before it was right. Not everyone knows how to rebuild one.Did you have them put a shift kit in? Isit smooth when it does shift?

dugan

it shifts the same it did before the tranny went bad and i had it rebuilt. i am not sure on the shift kit, i know when i had it rebuilt he used the same valve bodies that were in it, i dont think they are stock. when it shifts it is kinda rough, but not as in bad more like an aggresive shift.

jlp66stang

It should bepretty smooth, mine has a shift kit, it winds up more before it shifts, but is smooth. Does it feel like it is slipping before it hits.

dugan

no it doens't feel like it is slipping. when it shifts it is a really fast, hard, aggressive shift, i dont really know how else to explain it, could the gear ratio of the rearend affect this at all? i dont know what they are, the guy i bought it from didn't but i know they are fairly low ie. 4.11's or lower.

my77stang

you can adjust shift points by turning in or out the screw in the vacuum modulator. its in the middle of the fitting that the vacuum line attaches to. also, a simple shift kit does a world of difference in the C4

dugan

so if i turn the screw in will it raise my shift points or lower it?

falconfixer

And are you sure it is getting a good vacuum signal? Put a gauge on it at the tranny.

my77stang

i forget which way does what, you just have to play with it........ *chuckles*