Why does my truck fall flat on its face shifting into 5th at WOT (Tuned/ DPF Delete)?

lxcoupe · Mar 31, 2013

I am running IDP's Xtreme Street Tune (approximately +300rwhp) and I've been enjoying the hell out of it for about 5,000 miles. But lately, with the foot to the floor, the 3-5 shift goes completely flat. Feels like someone cut the power completely, then it sort of sorts itself out and keeps going. But when that happens, a lot of the time, when I come to a stop, the trans is stuck in 5th. I have to put it in park for it to go back into 1st. Then after that it might shift funky (shifts directly from 1 to 3, then gets stuck in 5th again), then it goes back to normal and the issue doesn't reappear unless I go foot to the floor 3 to 5 shift. FWIW, I do have the Gogo solenoid installed, fresh Motorcraft fluid, and a fresh Motorcraft filter. Truck has 69k on it, bone stock until 64k.

78f100 · Mar 31, 2013

Have you reloaded the tune? If not return to stock and reload, it may take care of it.

Dzchey21 · Mar 31, 2013

Signs of a slipping Trans would be my guess

4tonGT40 · Mar 31, 2013

lxcoupe said:
I am running IDP's Xtreme Street Tune (approximately +300rwhp) and I've been enjoying the hell out of it for about 5,000 miles. But lately, with the foot to the floor, the 3-5 shift goes completely flat. Feels like someone cut the power completely, then it sort of sorts itself out and keeps going. But when that happens, a lot of the time, when I come to a stop, the trans is stuck in 5th. I have to put it in park for it to go back into 1st. Then after that it might shift funky (shifts directly from 1 to 3, then gets stuck in 5th again), then it goes back to normal and the issue doesn't reappear unless I go foot to the floor 3 to 5 shift. FWIW, I do have the Gogo solenoid installed, fresh Motorcraft fluid, and a fresh Motorcraft filter. Truck has 69k on it, bone stock until 64k.

Dzchey21 hit the nail on the head, I had the exact same issue a year ago or so and I had fried direct drive clutches and I think some reverse clutches I think. Long story short , I had it rebuilt and put a stock 3-5 solenoid back in along with other goodies. Mine would get stuck in 3rd gear instead of your 5th but same deal.