i have a 90 rs with a 305 tbi and a 700-r4 auto tranny. lately its been having problems shifting. it wont shift untill it gets way up in the rpm's and then goes to the next gear, even durin normal driving. ill be doing 25 mph by my hoouse and running like 5500 rpm. ive tried adjusting the Throttle valve cable and that didny help, and ive had a couple ppl tell me it could be a modulator valve that runs off a vacuum hose, but i cant seem to find one at any parts stores. if anyone can help me id appreciate it.

thanx
chris

 

If this happened all at once, then a broken governor gear will do this.

 

ok...how much would that cost and how hard is it to change?

 

Pull off the governor, pull out governor & take it to the local transmission shop & have them install a new governor gear. $5.00-$10.00 should cover the cost. Be sure to install a new cover seal.

 

i have a 91 z28 with a 700r4. lately it has been slipping real bad between gears, usually only when i get up on it. but it has been getting worse. is this something small that can be fixed or are we talking about a transmission rebuild.

 

You are talking about a transmission rebuild.