Hey guys, 98 f150, 245k miles. 4.6 r470w, 4x2 Here's the deal, as I'm driving along today I notice a driveline problem. Under moderate acceleration, whether from stop or downshifting to pass at 70 mph, there is a hesitation in the shifting and a noticeable air-rushing sound. This hasn't happened until today. Trans fluid has been changed every 50k miles and maintenance is performed on a regular basis. Im thinking vacuum line but I read that the trans is all electronic. The air noise seems to be coming from under the hood. Here's the strange thing, the air noise is not present when truck is in neutral or park. Any ideas? I've already done a broad search and didn't seem to find anything so keywords or ideas to narrow the search would be helpful as well. Thanks for the help guys!

Stephen

 

That is weird,the only thing I can think of is the vent is plugged for the transmission. Maybe try it with the dip stick pulled out a bit to let it vent and see what happens.If the vent is plugged you might have fluid trying to escape through the dipstick tube so beware of the fire hazard of the oil on a hot manifold. Keep us posted.

 

Took it out for a test drive tonight. Other than showing it's age, it performed as it should. I forgot to mention the weather for last sunday when this occurred. It had been raining quite heavily here in CLearwater, FL for the past 2 days. Today has been dry and not humid. AFter driving in city for 10 minutes, then highway for twenty, there was not a single problem at all. The transfluid smells and looks brand new. I cannot think of any other pertinent details. Hopefully this was simply a fluke. Will keep this updated if anymore problems arise