C6 Tranny problem with modulator

[stucher]

Hi guys. I have an 87 F250 7.5L with a C6 Tranny. It started having shifting problems, so I pulled the modulator and found the diaphragm was shot; fluid was in my line. I bought a new black stripe modulator from Ford, and checked my vacuum which read 15. With the new modulator, my truck was shifting way to late. Prior it would shift into 2nd at 15, now at +25mph, and into 3rd 35mph, now +50 mph. I read about reducing the length of the pin in the modulator, so I tried that. It's original size was 1,700"; I took it down to 1,250" in very small increments, and the difference in shifting was only a few mph.

So I went to Napa this weekend, and bought another black stripe modulator, but this one was adjustable. Same results. If I backed off the adjustment ****** my change in my mph was only 2-3.

Is is possible I need a different color striped modulator for my truck? The online NAPA website lists a green and white stripe.

http://www.napaonline.com/MasterPages/NOLM...&SubCatId=5

Thanks in advance for any help with my problem.

 

[stucher]

I installed an adjustable green striped modulator today. With my original pin (length 1700"), and the adjustment ***** in all the way, it shifted into second at 29 mph. With the adjustment ***** out all the way, the shifting dropped to 25 mph. Way too high. I then installed my altered pin, that is around 1,250" in length, and it still shifted the same. Any help or recommendations would be appreciated.