I am new to the forums and did a search and came up blank so sorry if this is a common thread. I have a 01 F150 Supercrew with an auto tranny.

This only happens when the truck is cold. If I let it warm up significantly it's not a problem.

As I said when the truck is cold (and the weather) I get in, start the truck, back out of the drive way and put it in drive and head out. The first time I slow down (generally 50 ft to the first corner) the truck seems to up shift and the RPM's drop WAY down and the truck seems to Shudder and almost stall. Then if the give it gas it's no problem. It does this for the first few stops until things warm up a bit.

A little background. The truck has 70K miles. It only happens when it's cold and the colder it gets the worse the problem. The problem goes away in the spring/summer/fall. It is a little worse this winter then last. Last winter it never shutterd just up shifted.

Over the last 6-9 months it also seems to up shift unnecessarily when I am coasting and slowing into a corner, it's fine when I start to accelerate it just seems to up shift and a drop in RPM's.

I have had the tranny fluid changed twice over the life of the truck.

I have got plenty of knowledge of older Fords but the new one's I am lost on.

I am looking to see if this is a sign of a major problem coming down the trail, something minor that I should get fixed or something that I shoudl just drive until the tranny drops out.

Any help is greatly appreciated


Thanks,
Galen Weaver
'01 F150 SuperCrew
'66 Mustang 5.0 EFI
'70 Bronco set up for off roading

 

Here's what I would try first. I would go ahead and change the trans fluid and filter again, making sure you drain the torque converter as well. More than likely you have a 4r70w transmission and it takes Mercon 5 fluid. Do not use any other fluid other then Mercon 5 in this transmission or it will cause problems. I personally use Valvoline Mercon 5. It is a synthetic blend and came highly recommended by the local trans shop owner. Now keep in mind if you have the 4r100 transmission, it takes straight Mercon not Mercon 5. :santa:

 

On the door jam sticker under trans, U is the 4R70w and E is the 4R100. The 4R70w REQUIRES Mercon V, and the 4R100 can only have regular Mercon.

What was used on the last flush?

How bout the little things like plugs, wires, and fuel filter?

Adrianspeeder