hi i have a 2004 ford f150 5.4L lariat ... while driving at speeds of 40 and higher with my foot off the throttle it is fine as soon as i try to keep speed it shudders and if i step into it it will **** and be fine sometimes sluggish while taking off what is the problem can anyone help??? trans shop said about 1600 to fix and they couldnt even tell me what the problem was..

 

Don't think I am crazy with this advice until you try it, but I think I would look at the ignition first. It's hard to tell from your description, but that almost sounds like a missfire.

Obviously I am not there with the truck to feel it though.

Darrin

 

more than likely ignition problem like he said, transmission shops are great at rebuilding trannys and not fixing problems that are not tranny related

 

I've got the same year and model truck, except my trany makes a whining noise between 40-60 mph. Ii found a video on YouTube, but it doesnt really tell you much, just shows the drive shaft while driving, and you can hear the noise.... in the comments he says it was bearing, anyone else hear anything about this? Also in my truck, it feels like something in the rearend is shifting when I step on the gas...everything seems solid though...

 

Here is the video:

http://www.youtube.com/watch?v=Qli4uQJJjrk

 

I'm having the same problem with my 04 f150 tranny. Just started recently, if I'm up above 40 mph and it kind of settles into gear(off throttle like you said), and say I'm going up a hill or want to get back on the gas, it feels like the tranny is slipping(has 3 slips/bumps). It's difficult to explain without actually feeling it. Took it to the shop and was told my torque converter is going out.....possibly be something you should look at? My tranny problem could be my stupidity though, I've had an edge evo programmer since april 10' and have had it set on setting 2(Towing performance) and I never tow anything, so that's probably caused havoc on my tranny.
Hope this helps
-Jake

 

Thanks, I'll look into that. Don't have a programer though...yet

 

I also had very similar issues with my '04. I also had an Edge Evo , started to un-modify my truck in preparation to trade in last year. As soon as took the Edge tuner off (reverted it back to the OEM tune), the trans went totally back to normal and I actually liked the changes enough to decide NOT to trade it in.
I also had a Volant CAI, which "moosed"/hummed when the engine saw any real load or at WOT. Considering that the Volants cause 04-05's to run dangerously lean......that could have contributed to some of the issues I was seeing/feeling/hearing with the truck.

This time, I'm considering getting a newer color Edge (CS or the touchscreen one...) and getting some custom tunes/gryphon setup and an enclosed type CAI converted to run with a snorkel.

 

Put the stock intake back on and do a Gotts/DWV mod to it.

 

I've got the exact same truck and the exact same problem!! Off the line it feels like it is slipping slightly and then cruising around 45 mph. It feels like the engine is misfiring. Tranny shop also told me around 1500 to fix it. If y'all figure out what the problem is please inform me cause im a little scared to even take mine down the interstate for fear of it goin out. Thanks for the sharing now I don't feel like.im the only one with this problem

 

Hey guys, alright well I took out my programmer and sold it, but still have the same old transmission problem. Took it to the shop and had the drive shaft taken out, put what's called "XG8 Teflon Lubricant" on the drive shaft and that got rid of the "feels like the rearend is shifting when I'm taking off" if that makes sense. I'm still getting the slip/bump feeling at about 40+ though, usually in 5th gear. So I took the truck back in, mechanic(good friend of mine) had a F-250(not sure what year) come in with the same feeling/problem. Guy that owns the F-250, owns his own transmission shop and had no idea what it was. They changed the torque converter and that wasn't the problem. So I'm still waiting on a solution, when I figure it out I'll make sure to post on here. Any other input will be greatly appreciated!

 

Sounds like you and I have the same problem lol. If I romp on the gas off the line, it feels like my rear tires are just spinning at certain points, or something along those lines. I'm not sure what an engine misfire feels like or sounds like so I don't know if that could be the cause of our tranny slipping or not...like I said I'll make sure to let ya know what we figure out.
-Jake

 

Have you checked your plugs? COP's?

 

That's next on my list to try. Was reading in another forum the COP's were the fix, so I'm hoping they work.

 

Any updates on your problem? I am having the same problem and would like to hear what fixes yours....also my o/d just started turning off by itself.....hmmm?