2007 5.9 with 48RE Automatic....I am experiencing "Shifting issues"

[Steakman1003]

I am experiencing issues with 727 4 speed Automatic trans not wanting to shift after I give it a decent pedal with the 5. 9 Cummins. I have to let off pedal to get it to shift from 3 to 4th most of the time as Cummins is reving at 2800 RPM with light pedal even! It can be on a roll or off the line it does this. If I am easy on pedal off the line, seems to shift like it's supposed too almost all the time. I have a Bullydog Diesel GT Tuner in it also. I even tried putting Computer back to stock, but it didn't change trans shifting issue. I reloaded BD program back in again. Didn't change trans shifting issue ether. Wondering if it is the TPS/Pedal unit that cntrols so much that is hicupping? Please help if any ideas for me to try!

Steakman is New England

 

[F-15I Ra'am]

Maybe Transducer and Governor Solenoid?

 

[MChrist]

Unfortunately, the transmission in your truck is the weak link. My converter was fried at 35,000 miles, and I had plans to start bumping up the power. I took my truck to Dave Goerend and found that although the trans itself was mostly fine, the friction disc in the converter was shot, internally leaking, and not holding any power. It was acting like yours is now, upon full throttle, the RPMs would shoot up and stay there while the truck decided to get up to speed. My truck would not do a "brake torque". Truck felt very weak and sloppy.
After Dave installed his triple disc converter and beefed up the rest of the trans and whatever voodoo he performs, the truck is night/day different. Now, the power from the Cummins actually transfers to the rear tires and shifts like it should have from the factory.
If your trans or converter is shot, and since you are most likely going to increase the power over stock, you really need a beefed up transmission.
Dave will send you the parts you need, and you can have a local trans shop install the parts if you like. He can talk you through everything.
There are several horror stories about trans guys on this forum. You won't find a single one about Dave. He is that good!!
I think his website is : www.goerendbros.com
Or, just search "Goerend Transmission"
Oh, and welcome to the forum. Hope we can help.