HEy! I just wanted to share my joy with everyone. The Bronc'nstein has a c-6 that has been acting up lately starting to shift sluggishly and shifting hard sometimes not wanting to shift at all. Well I went to a tranny shop here by Fort Campbell and was quoted 360 for a rebuild. I thought that wasn't too bad and went to work. Well I was shooting th s&*t with one of the mechanics and he said that he used to work for a tranny shop that was more crooked than all of D.C put together. Anyway, he said that they used to quote "cheap" rebuild prices like that and then just replace the vacuum modulator. So I check it out and sure enough it's not holding a vacuum. Well I jump for joy and run to to the local auto parts store and for $9.99. I drive the Bronc'nstein home knowing what it feels like for her to shift smoothly. I almost cried. So all you c-6 guys having tranny trouble please check your vacuum modulator and save yourself some money. Also one last bit of advice, change it when you get home and have let the tranny cool down, and not in the parking lot of your local store 5 minutes after you park.

Gurahl and his Bronc'nstein

 

Nice to hear you found your problem. btw did you know most of those vac modulators are adjustable? you can change your shift point if you remove the vac tube and screw the inside set screw in or out with an allen key. Have fun!

 

No, I did not realize this. What would be the benefits of adjusting it?And what would be the best way to adjust it? Which way adjusts it? Sorry alot of questions..

Gurahl and his Bronc'nstein

 

I just bought an 88 - 302 with auto trans... (what is the OD auto they put in then, I know it's not the C-6... figured it was an AOD but not sure.) Anyway, it shifts hard into OD at low speeds, especially driving around town. I always drive in Drive and manually shift into OD once I'm over 55 or 60 mph to bypass it. Could the vacuum modulator be part of my problem here? I assumed the previous owner had probably messed up the OD by towing with it in OD... Could I be lucky enough to fall under the cheap fix you mentioned?

 

The 88 302 was fuel injected. There is no vac. mod. on the AOD. It uses a TV(throttle velocity) cable. This can be adjusted, but I don't have the info available. Try the tranny forum on this site.