Hi all! I have a question for everyone out there with any insight of the harsh shifting with these trucks. I have a 2003 f250 super duty with the 5.4l and 126,000 miles on it. The problem I'm having is some weird shifting that has been going on over the last six months and I feel like I am just throwing money at this problem. My truck shifts hard from 2nd to 3rd and from 3rd to 4th with the most violent shifts being from 3rd to 4th! Between shifts is where it Is sluggish I mean if I am not on the throttle from those shift points I switch from driving a truck to a geo metro it is night and day with the felling of loss of power! I have had it scanned at my local ford dealership and had a full diognastics done and all I got was "it's since truck and a nice bill to come with it" they couldn't find a thing. So I started looking at other forums of similar situations and throwing money at this problem. So far I have all new motorcraft plugs, cops, changed fuel filter, had my catalytic converter checked if it was clogged,run on two different power balance tests! Still nothing! So now is where I need help I'm lost I have heard things about these trannys and the lock up but I was told this only had to do with overdrive and it wouldn't happen at other gear changes. I still drive it everyday I have just figured out ways to calm it down if I stay off the gas when it's about to shift for a couple seconds then get back on the gas it is like it never happened. I am open to any suggestions and I appreciate all the help I can get!

 

The 4 speed does lock and unlock between gears not just in OD. It sounds like you have a mechanical problem with your converter, when is the last time you changed fluid and filter.

Denny

 

I can't wrap my head around how this could be a mechanical problem with the converter. Can you help me understand how that would work?

 

I have not had it changed since I bought it this January but they told me it was changed when I bought it but it won't hurt to get it done just to be sure! This is what I was afraid of was a tranny problem haha that's why I tried all the cheap stuff first! Thanks for the reply

 

sounds like a common problem's here.....
1st- Ford did not install a spin on filter on the 4R100 transmissions, go on summit and searcg trans filter and buy one of their kits
http://www.summitracing.com/parts/der-13090
2nd-the boost line valve is aluminum on aluminum and is a known wear item, valve digs into itself and causes hard or low shift pressures
3rd-aluminum shift valve dig into the aluminum valve body and also cause soft or hard shifts
4th-stock shift springs are know to break causing soft or hash shifts

i went through this with my 2004 in my sig, almost two years i played with transmissions shops, looking for problems. In the end i bought Trans Go upgrade parts and also installed a larger steel boost valve, steel shift valves, and their HD2 reprogramming kit. 120 dollars later i have a 4R100 that shifts better than anything Ive ever driven, been in or seen shift before

 

http://www.summitracing.com/search/p...s-remote-mount

 

When they shift the converter unlocks and then locks back up depending on the load. Under low load you don't even feel it but under load you can see it locking up with your tach. You have no codes so my guess would be the converter isn't locking up right. On the 2000 tuck I just traded under load hot it would rattle your teeth when it locked up, when it was new it had a good smooth lockup under load pulling hard, I just put it off as wear in the converter because it had no codes, unloaded it worked fine. Take it to a good transmission shop that will look past their code reader.

Denny

 

Thanks for the reply superdutyscaler! How big of a job was it to do all those upgrades. I would be happy with a $120 fix right about now but I am not a big transmission guy! I have done the same took it too some transmission shops already and I was told they don't see a problem but I drive the truck everyday and see it (sometimes when you take a loud lifted truck to a shop they forget to find the problem rather than taking a joyride haha)! I appreciate all suggestions

 

Rvpuller! So is this just something where you could upgrade your torque converter?

 

If that's the only thing wrong then yes but if it was mine I would have the transmission gone through when it was out. It's cheaper to have your freshened up before its toast. Being it's a lifted truck has someone already installed a kit in it? Maybe they installed it wrong or just made the shifts to hard. Your aren't the original owner so who knows what was done to it. You may also already have a upgraded converter making the shifts hard. It's a lifted truck so what size tires are you running and were the gears changed to compensate for the bigger tires. If it has 3.73 gears and you are running big tires that could be your problem, it feels sluggish because the gears are to high. Jack up the rear of the truck and mark the drive shaft and one tire then turn the drive shaft (count the turns) until the tire makes one revolution. If it turns 3 3/4 times you have 3.73, 4 1/3 times then you have 4.30 gears and so on, it's not exact but it will give you a idea. If you have 3.73 gears and big tires that's not a good combination.

Now that you said it's lifted I'm willing to bet you need a gear change.

Denny

 

i never had any transmission apart before, i read threads on this site where guys posted pictures of how the four valve bodies are removed then i watched the Trans Go video on the same procedure. I'm very **** about my truck so i took extra time removing everything, cleaning the valve bodies and double checking the torque the bolts back to spec. In all it took me three hours which wasn't bad at all. Once you see the videos and pictures you'll be like O this isn't bad at all.

 

i just helped another member with the same problem as you, took it to a bunch of shops and they all said o you have alot of miles you need a rebuild. He finally found a shop that would just take it apart and look, i told him to tell the shop exactly what too look for and sure enough he had broken 2-3 shift springs. They installed a new set of stock OEM shift springs and he told me the truck is back to new again.