Truck slams into each gear when automatically shifting
 

I have a 1994 extended cab F150 which I bought about 5 years ago. The truck only had 60,000 miles on it when I purchased it.

After a week of owning it, I noticed that every once in a while, the truck would violently slam into each gear when shifting. The shifting would shift so hard, that it would push you back in your seat.

The truck was still under warranty, so I took it back to the Ford dealer and they said the transmission was bad and replaced it with a brand new transmission from Ford.

A week later, the same thing started to happen. Can someone tell me what the problem is and what I can do to get this fixed? Since the new transmission is also acting the same, what is the problem?

Also, once in a while when I am driving on the highway, the truck will slip out of Drive and seem to go in to neutral for a couple of seconds and then it goes back into drive again by itself.

You either got a bad rebuilt or the cooler lines had metal in them from the old trans that went out and they didn't get cleaned out during the trans swap. Warranty on transmissions usually only get you a rebuilt not "new". Don't quite understand, have you been driving it like this for five years - two weeks? Why wouldn't you bring it back to the dealer? As for the random neutral, trans problems only get worse over time.

Yes, I have been drivivng it like this for 5 years because the problem only occurs about 10% of the time and I only used the truck 2 times a month.

Which cooler lines are you talking about? Is that an expensive fix?

Could it be the speed module that is located in the rear differential that tells the trany when to shift?

Thanks

Not sure if it could be a sensor. There are two metal lines that run from the right of the trans up to the radiator. One is a out and the other is a return. When a trans goes out usualy something comes apart and small pieces of metal floats through the system killing other parts. No way to fix it now, if the dealer didn't flush the lines you may have gotten some of that metal into the new trans. Try replacing the filter and fluid. When you pull the filter see if you have a lot of metal bits on the screen, this should tell you how bad off you are. You may be able to drive it for a long time like this, but with the random N's your probably looking at a new trans some day.

Any other suggestion to my problem? Should I rule out the speed sensor altogether?

The random Neutral could be caused by MLPS.. Thats the sensor on the trans where the shift cable attaches, My 94 would do that also and I just replaced it. SO far haven't had the Neutral problem since. Only been a few weeks though,, will see..

Thanks MA94XLT, how much did it cost you to fix it? Was it a big job or could you do it yourself?

Thanks

The parts runs about $50-60.. Not too hard of a job. Have to take off shift cable at trans and make sure new MLPS is lined up correctly. There is a special tool for it, but can be done without it. The new MLPS had a line on the center rotating part and on the housing. Put shifter into neutral position and made sure the line on both parts line up. So far been doing ood..

What does MLPS stand for?

Manual lever position sensor. It just tells the computer what gear the transmission is in.