I have a 1998 F-150 4x4 with an automatic transmission. Bought with 168000 miles, now 171000. I have noticed that after exiting the highway the transmission will shift very hard. Sometimes it stops on it's own, sometimes it keeps going. Truck runs excellent other than that. I have found that there was something blocking the O/D light. The light does not flash at all until you are on the highway for a few miles, then it continues until the truck is shut off, after that it starts all over again, not until driven at highway speeds. It appears that the torque converter is not locking up on the highway. A slight touch of the gas and the tach goes right up. The fluid smells new and I have replaced the VSS, as recommended but a local shop. There are no codes in the computer. Any ideas?

 

Before you spend the money on a rebuild, I would pull the filter and clean the magnet and put new fluid in the tranny a long with some lucas and see if that solves your problem. It did on my truck. My truck was shifting hard and acting strange, new fluid and a filter with some lucas did the trick.

Good luck

 

For some reason, these transmissions love fresh, clean trans fluid. The recommended change interval is something like every 30k. Like bowdog said, I'd try changing the fluid first. Don't forget to drain the torque converter too(if it has a plug).

 

wait i didnt know i had to clean the magnet on my truck, im going to do my tranny fluid change this weekend, anything weird i should expect?

 

Nothing too weird. If the pan has never been off before, you'll find a plastic plug in there. Just throw it away.

 

I second that except for the Lucas. The additives don't fix anything, they mask problems. If you are trying to fix a problem, you want to know if whay you just did resolved it. If you have a additive that hides the problem, you will make the problem worse. The new fluid and filter alone might be all that you need. If the OD light comes back on after that, you have a real problem that needs real attention.

 

i assuming that i will get a new plug with the kit?

 

Nope, the plug just keeps dirt out during assembly. When they install the dipstick, the plug gets pushed into the pan.

 

Keep an eye on the pan gasket, most filters will come with one and in most cases you do not mess with the stock gasket.