Someone please help! I have a 99 F-150 4x4 S.Cab 5.4 w/13k w/4r70w and tow package. This truck was bought as a wreck regular title (hit about an 8" tree). The truck sustained front end damage only. The engine starts and runs fine. The problem I am having is the truck goes in R and N like it is suppose to and does what it is suppose to but when I go to the forward gears the truck will not move until the RPM is about 2 grand then it slams in gear. After the truck starts moving the trans. acts like it is slipping(i.e.while driving the RPM goes way up) I have driven the truck only about a mile from the time I brought it home to the present. I have not pulled the pan yet to check if something from the trans. cooler "which was smashed" entered into the tranny. The local tranny shop thinks it more of an electronic problem rather than a mechanical one (said it could be locked in "failsafe mode") what ever that is. The dealer will not warranty the tranny because of the wreck, even though the truck is still under warranty. Does anyone have an idea of what might be wrong?

 

It does somewhat sound like an electronical problem. Try resetting the computer by disconnecting the negative battery cable and running all your lights for about 15-20 minutes. Then start the truck and run throught the gears, just a wild suggestion, thats what process of elimination is all about. If that isn't the case, it may be a mechanical problem in the valve body, just my $.02.
-Kelly

 

Thanks for the response Whiplash_150, I tried the battery disconnect but that did not seem to do anything. The valve body is something that I have not looked at yet, Mainly because I would not have a clue what I would be looking at. (I'm an Electrician and not a Mechanic.) Well maybe I should let the tranny shop take a look at it. Thanks again Whiplash_150. If anyone else might have a fix please respond!

 

Hi Mburke

You didnt say any warning lights came on....

That tranny is hooked up to the computer. Im surprised the TCL light didnt start flashing.

Anyhow, have a scan done of the computer. If a trouble code has been thrown, that will give direction.

Maybe they dont scan if no trouble light on?? But that diagnotic port was put there for a very simple reason...to eliminate alot of guess work and expense.

As i recall the fail safe has to do with lose of coolant, overheating etc but ..? BTW you know for sure you need a new tranny cooler and fluid.

Good luck. OT

 

there are two things i would check right off.

(1) tranny fluid levels
(2) the oil pressure for the trans.

it really sounds more like there is no hydrulic pressure, more than an electronic problem. A friend of mine has a truck that does the same thing, and it's a bad seal in the trans... (we know what it is, just don't have time to fix it)