Couple month's ago trans wouldn't go, engine would rev and eventually trans would grab and go. Found low trans fluid level. Filled it and truck ran fine. Then I noticed a puff of white/gray smoke from exhaust occasionally. A week later trans slipping again. No leaks under truck and trans fluid level was low again. Changed trans filter and fluid that was in the pan during removal. Filled fluid again and it ran fine. Another week and slipping again along with the white/gray smoke from exhaust. Realized fluid was leaking from trans to the engine intake through vacuum modulator. Replaced it with a Fram modulator. No more fluid drop or smoke but now trans slips/hesitates between gears. Pulled the Fram and installed the Ford OEM Motorcraft modulator and slipping was less but is still there between gears.
Any ideas of what is going on????
I hooked vacuum gage to intake and I've got approx. 16" wg during idle.
Another question. My Chilton book says to remove the modulator and the modulator control rod. Install control rod and then modulator. Is this control rod attached to the modulator? I saw a rod/spool behind the modulator but didn't dig to get it out just so I could put it back in. It wasn't mechanically attached.