I have a 1990 F150 XLT Lariet with a 300 C.I. inline EFI 6 cylinder engine with an automatic transmission with overdrive. For sometime the transmission has had a hardshift when going from overdrive to drive and then back to overdrive. On occasion when shifting it will go to what seems a neutral positon, not slipping just freewheeling. It has only done it on occasion, never consistently. The other day it did a rough down shift and when it started to shift back to overdrive there was a loud pop and now it will not take any forward gear. The transmission has never slipped. Is this a modulator valve problem or something more serious? The truck has about 115,000 miles on it. Any help will be appreciated.

 

Hello, My sons tranny is doing the same did you ever find out what the problem was. I cant find any thing on here that can help us.
""On occasion when shifting it will go to what seems a neutral positon, not slipping just freewheeling. It has only done it on occasion, never consistently.""