I have a Black Maxx installed on my truck. Works great, plenty of power, though I have notice the transmission has had an occasional issue since I installed it.
It tows fine, works fine, but a couple of things...
1) Sometimes it upshifts too quickly to sixth - sometimes going up a steep hill it jumps to sixth gear and starts lugging. I have to accelerate a little to make it downshift, or use the shifter buttons to force back down into fifth.
2) The transmission sometimes forgets to go into gear... on 3 or 4 occasions now, I'll put the transmission in reverse, and it take a few seconds or sometimes cycling through Park to get it to go. Not a big deal - maybe 3 or 4 times in the 10 months or so I've had the chip in.
But last night, I started the truck, pulled out of my driveway, and the truck slipped out of gear, or something... I started to accelerate slowly, and it tried to shift to second, and didn't. It was like holding the clutch down in a manual... the engine just revved. I slowed down and stopped, shifted to neutral and back again, and then it worked fine, but it made me nervous. I thought I smelled something odd, then realized it was the neighbor burning his garbage.
Anyway... I have 36,000 miles on the truck, and this is the first Ford I've owned. Otherwise I've towed like crazy with it... fifth wheel toyhauler, gooseneck trailer with skid loader, light trailers, big trailers, you name it.
I drove it to work today and it ran just fine. First thing I'll do when I get home tonight is to upload the latest H&S Updates to the software. I have the EGR delete and the H&S exhaust, so I can't really run the truck very long without the chip in place to do any kind of long-term testing.
Have any of you seen this? I hope it's not a major tranny problem, but I'm thinking it could just be the computer getting confused as to the gear assignments because of the chip. Hoping I can just update the H&S chip software and get it working again.
Any experiences or comments that may help me understand this? All other maintenance has been followed by the book, performed by the dealer (who is fascinated by the mods I've done, incidentally. They're helpful!)