Disappearing Transmission Fluid
I'm the second owner of a 160,000- mile 1994 Ranger XLT, regular cab with short box, 4.0 L OHV V-6 with a 4sp-OD automatic. A few months ago, it began shifting improperly and not engaging in gear properly, especially when cold, first thing in the morning. Checked the transmission fluid and found it about 1-quart low, but color and cleanliness were good. I had been advised that it had been changed religiously at 12,000 to 15,000 intervals since new. The 4.0 OHV V6 has never needed oil added between 3,000-mile changes, so I began focusing on the transmission and neglecting oil checks. While ignoring the engine oil level and adding about a quart of transmission fluid per 500 miles, I continued musing about where the fluid was going. Carefully watching parking areas, and even inspecting from underneath the vehicle for any sign of leakage, I found none. I just kept adding transmission fluid as necessary, too busy to think much about it, but still bothered about where the fluid was going. When Christmas came and I was planning a short highway trip to visit my family, I returned to my regular habit of checking all fluids. I found the engine oil level a couple of inches over full . . . the missing transmission fluid. The vacuum modulator for the transmission had developed a diaphragm leak and was siphoning transmission fluid into the intake system, with it eventually ending up in the engine oil. A new transmission modulator solved the problem(s), and the transmission fluids and engine oil stay in their respective places. In addition, shifting is better than I've ever experienced with this vehicle.