My brother in law has an 05' F-350 6.0L, 5 speed automatic. He is having an on going problem that the local dealership can't seem to remedy. So we were hoping that you guys might be able to help. Here is the problem... When your on an incline for instance Wilkerson pass, Ute pass keeping the peddel at a constant and as the rpm starts to decline as well as speed the truck (60-50 mph) before the down shift from 5th to 4th the truck will shake and make a whooping sound it only last 2-5 seconds. Then the truck will down shift and the rpm will increase and it then runs fine again. It sounds like it's missing. The dealership has re programed the PCM 3 times, and stated that their was a loose wire in the glow plug regulator( they said it is electronicaly in line with the transmission. Not quite sure if I agree with them. Please help!!
What happens if he lays right into it, to force it to downshift? Does it to the both in and out of Tow/Haul mode?
1 Ton Hauler W/ Toys Talked to my brother in law. He had stated that he hasn't used the tow/haul mode. He only hauls 2 atv's. And on another note he also told me that if he lay's into it it doesn't have the problem. He is taking it to Phil Long Heavy Truck Service tomorrow. :stir: