I have '09 F-250 6.4 crew cab pulling a 5th wheeler. I am using Supertuner in tow mode. When I am going down the highway at like 60 and I have to slow down for moment then get back into it , it feels like it is slipping .I dont really know how to describe it actually..kinda like there is slack in hitch or trans slips for like 2-3 secinds then it goes right back to towing perfectly. I am new to towing 5th wheeler with the hitch in bed? any thought greatly appreciated. Truck has 27K miles on it . Never had a problem with tranny ? It just bothers me..

 

I've towed a 5er for over 10 years I'll see if I can help. Is this a new thing? all the fiver hitches have some front to back slack in them. On a hard stop they will slide forward and go clunk, then when you start off they will slide back and go clunk. Depending how much you are slowing, it could just be the pin sliding back in the hitch and going clunk.

However, you say it feels like it's slipping. Slipping is not good but you may just think it's slipping. Do you have a tranny temp guage? Besides the one on the dash? Anyway, if it's a tranny slipping the temperture should be going up some when it slips. Keep an eye on it.

There is some slip built into an automatic as the clutches slip up to speed and the torque converter locks up, but it should not be enough to bother you like that.

If you can feel a sharp clunk when the slack ends I'd be comfortable saying it's slack in the hitch. Otherwise, I'd keep a close eye on the tranny and if the slipping gets worse have it looked at before you do more damage. Should be under warranty from Ford with only 27,000 miles.

hope this helps.

 

tow with it on stock power levels and tuning and then how does it feel?

 

StanleyZ, I know the clunk feel, but this is different .I wish I could describe it better, It is almost like it takes off & lets go 3-4 times before it settles out. It does Not do it all time . It seems like if on up hill incline after slowing up a second and then getting back on gas. I will keep an eye on trans temp. & see


Senix, I was thinking about doing this myself next trip out. I also tow in tow mode on trans??? Is this a bad thing with tuner in tow/haul program?

Thanks for all of your inputs I appreciate it..

 

using the tow/haul program is recommended.

I think the problem is going to be the programmer myself. No trans tune?

 

Well, I will find out this weekend, I will go back to stock and see what happens!

 

What part of the country are you in? I ask because I'm wondering if you are experiencing a loss of power rather than a slip. Next time it happens look in the mirror for smoke. These trucks have a known problem with moisture accumlating in the CAC tubes then when you call for more power the moisture gets sucked into the intake and causes a little miss and a loss of power. If you keep your foot in it the truck recovers nicely and goes back to normal. Could that be it? This problem is worse in high humidity or rain.

Otherwise, I'm with Sennix, something in the tuner. What size tune and how heavy is the 5er. Most folks on here feel towing should be done close to stock settings. My tune is +35 HP and 110 torque. The tuner company says I should tow at the next setting but I'm having a good experience where it is. if I could back the tuner off to "stock" I would. So try that and see what happens, and if you feel it again pay real close attention to if it's slipping or losing power. Hope this helps, let us know how you make out.

 

Could it be a cutting out? I have an 08 6.4 that does this most noticibly (and severly) while towing. I hit a small bump or inperfection in the road, or start up a hill at a moderate speed and it feels like the fuel is cutting in and out which causes the truck to buck back and forth. It will do this untill I let off the throttle and slow down. Without a trailer, it's barely noticeable. Like the trailer weight accentuates it. Had done it since I bought it with 8K miles on it. Getting worse so much so that i have quit driving it. SO now I have a $50K truck that just sits. Barely out of warranty and been to the dealer many times. No one can figure it out. Replace #2 6 and 4 injectors, new EGR, New turbos in '07 still had problems.

Also often get trailer fault warning. Dont know if related. Just fed up with this truck and looking for an answer

 

Wiring harness for the HPFP?

 

senix, I really appreciate your thoughts..

What is the HPFP?
Taking it back in on Monday. FYI, in addition to all the the other repairs, there was a bent push rod, the radiator replaced and last friday replace the electronic throttle control.

Really tired of throwing parts and money into this truck

 

also, I own several trailers, doesn't matter which one I pull. Flat bed or horse trailer, even with a friends trailer.

 

High pressure fuel pump. There is a wiring harness to it that has been known to rub in the early trucks.

 

Won't it be something if that harness turns out to be the problem after Ford did all those other repairs. Where does it rub, I have an early 08, maybe I can head it off.

 

Mine is an early 08 as well. Put into Service Feb 07 AND the rotten luck of being ofne made in the Kentucky plant ( where most issues came from)

True Lemon mine has turned out to be.

 

see this:

Misfire, rough running, lack of power:
Engines built at the Huntsville plant, serial number 0425659 or lower, or at the Indianapolis plant, S/N 7004400 or lower, may exhibit the above symptoms, possibly intermittently, along with open injector circuit codes P0201-P0208. First, check the harness connector(s) at the affected bank(s) at the rocker box to see that they are fully seated. If the condition remains, the valve cover for the affected bank should be removed and the individual injector connections inspected. If no connector concerns/damage are found, continue with normal diagnosis. Broadcast Message 6968, 7336.