I have a 2007 f150 lariat with 88000 miles on it that i just bought and during slow throttle from 40-50 i am getting a sparatic shudder right when it goes into overdrive is worse when going up a light grade it goes away when i get to about 60 and whenever i give it full throttle it acts realy sluggish like the tranny is slipping but it shifts very smooth. any ideas?

 

Have the torque converter in the tranny checked... I had a Ranger that did this and it turned out to be the torque converter.

 

Also had something similar happen to my T-Bird. In my case it was an aluminum ring in the tranny wore/broke and filled the tranny with aluminum shavings, pan was full of them. I had to have a tranny rebuild in that case.

Hope yours isn't that bad. Good luck.

 

i heard that when you press the brake pedal the torque converter unlocks so i tried pressing the brake when it happened and the shuddering didnt go away could this be a tune up/ cop problem?

 

I would think that if it is a tune up /cop issue, the truck would shudder no matter what gear it was in. I have not heard abou the TC unlocking just becuase the brake pedal is pressed. Yours may not be locking up at all.

 

Have you changed the fluid and filter? If not its worth a try. I've had some do this and it cured the T/C shutter at low lockup speed.

 

I know the 4L60e in chevy trucks would unlock the torque convertor when the brake was pressed and if the bpp switch went out it would not lock up at all. So that is not completely false but i do not know if the same function applies on these trucks. If you can easily duplicate it a good scan tool will tell u when the torque convertor is locked or unlocked. Even if you have to pay a diag fee that would point you in the right direction. If you decide to service it I would add a bottle of the motorcraft friction modifier it did wonders for shudder in the 4r70w ford transmissions.

 

Just did a live data recoding on my cen tech and I don't realy know what to look at to tell if it is misfiring but when the shuddering happens after it shifts the truck was at 1304 rpm and had a spark advance of 23 degrees and I don't think that's right also fuel rail pressure was at 38.8 psi which seems good but I don't know

 

I think i would start with a trans flush first. If you had a misfire you should have a saved code.