2008 f-250 6.4L 4x4 Ext Cab 108,000 miles.......Two months ago I installed the DPFR+4.0 Cat/DPF delete. The day I installed it, it slammed(not to hard) into 3rd gear at 1/2 throttle. I thought the trans just had to relearn so i took it easy for a week or two. Obviously it was not a relearning issue it hasnt stopped acting funny. Now, it just revs up a bit( like 200 rpms searching for a gear) as its shifting into 3rd or 4th. This only happens when i go to half throttle. It switches gears just fine when i drive like a grampa. I did not notice any of this pre DPFR+4.0. I contacted Gearboxz and they say its not the programmer. I have disconnected both batteries and touched the positive to the negative for 20 minutes to reset computer and it is still doing the same thing. Could it be a sensor? Do you think its related to the programmer? Apparently this programmer does not mess with trans and shift points. I would rather not take it to a trans shop now to rack up a bill if its related to programmer. I read other posts about this but there wasnt a clear answer- sensors, clutch discs.......Thanks in advance for any info.

 

Couple of things I am thinking.

What ATF are you using and when was the last service?

Are you running in stock power levels or have you tried in?

Have you scanned for any codes?

What about putting the cat/dpf back on and retune to stock programming and what happens then?

 

..with the DPFR, you can run your factory flash without dpf or cat in place. No need to reinstall.

The damn things runs perfect when I drive normal. Once I go 1/2 throttle from a stop is when all these problems happen. I answered your questions after your comments.

 

Try the factory flash is what I would do.

Perhaps part of the TCM, trans control module is having an issue.

Mark will know best.

 

Whenever I am asked to diagnose a trans problem the first step is to ALWAYS remove any tuner. They can cause transmission problems WITHOUT changing anything in the transmission programming. Changing the engine programming is enough to give the transmission fits.

Your trans was fine until you installed the programmer. It is the programmer. Period.

 

I flashed back to stock and it is not reving between gears. The weird thing is that i can tell it isnt shifting right into 3rd gear with the stock flash. It seems as if the problem is just multiplied with the tuner. It is just shifting rough into 3rd. I guess i have just not noticed it when i was running stock before the tuner. I dont pull much and dont get on it much and the problems dont occur unless you go half throttle. Ive heard of the early model 08 trans having trouble with shifts but I dont know what is causing it. Any suggestions?

 

Do you have a gearbox z? I do and I was told not to any tuners with flash. You can monitor only.

 

Did u buy the truck new ?

If not, the previous owner "probably" had a high horsepower tune that Damaged the Tranny.

Tuners are MURDER on Transmissions IMHO

 

I have the edge insight, it's a monitor only. The DPFR 4.0+ is the "tuner."

 

I bought it used. Everything appeared to be original. When I took the dpf off I found no signs of it ever being taken off. It shifts a lot better with factory flash, just a little rough into 3rd. I'm going to flush the tranny soon to see if that helps. I'm just confused as to why it revs up while shifting with the DPFR 4.0. I don't see anyone else having this issue with the programmer and wanted to hear what you guys know about shifting problems with the early model 5r granny's.

 

Okay. I have the Gearbox-Z only it just delete the cat/dpf and closes the valves to egr.

 

What happens if you go full throttle?

 

My boost hits 30-35 and I'm Moving pretty quick.

 

Some tranny's just don't take well to the tuning. Just the way it is.

When I tow heavy I always run in stock power. Tranny is just better there. This is another case of it.

 

Honestly I haven't even tried because I felt it might screw something up. Especially since half throttle is already causing it to have problems.