Hey Guys. Hoping to get a little insight here. I have a 2007 Lariat super crew 4x4 with a 5.4. Its sporting an 8 in lift and recently got some new 38in Toyo MTs. When I installed the lift I went ahead and swapped the factory 3.73 gears for 4.88s to help pull the new big tires. Recently I have noticed that in overdrive if the speed slips down to about 40-45 mph the truck starts to jump and it feels as if there is a catch or something in the drive line. Its a very hard thing to describe if you haven't felt the truck do it. RPMs don't dip and if a little gas is applied and it shifts down into 3rd then back up to 4th it stops and as long as speed holds steady around 55-60 mph everything is fine. With the 4.88s I wouldn't think I would be having transmission issues at only 106,000 miles but I really don't know. I've never been one to play in the mud or rawhide it. It has been meticulously serviced at the Ford dealer where I bought it and the heaviest thing I tow is my '09 Brute Force on a 5x10 trailer. Any help ideas would be greatly appreciated

 

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I have no clue... When my truck starts acting up I take it to a shop... Sorry man... But it sounds like its a sick truck tho

 

If its in third does it do it still?

 

No third gear seems to make it stop. Its only in fourth that it does it. Its almost like when a standard transmission speed gets to slow for that particular gear.

 

@southportandford thanks man! I'm probably gonna end up just taking it to the shop before too long. I love the truck and would hate to not be able to use it.

 

Did u do the 100,000 mile tune up? That might help if u have not done it yet

 

No last time I had it serviced they asked if I wanted to do it and said it would be $500. So I passed on it.

 

Does it do it when the OD/Tow/Haul button is pressed? If not it is possible that you have a bad direct clutch assembly. It is also common for the one-way clutch retainer ring to pop off causing shift/pressure issues. Is the fluid clean or a dull red with a burnt smell?

 

i had hiccup feeling with my truck when in 4th ...would happen occasionally. i had the plugs changed and it hasnt done it since. it was a very minor misfire.

now i also have a huge vibration issue that comes and goes, but ive narrowed it down to my tune....thats a whole other can of worms