I have a 99 F250 SD 4x4 with a gooseneck mounted to the bed for towing a 2 axel gooseneck horsetrailer. My problem is that when towing the gooseneck, or the bumper pull flatbed for hay, I get a surging motion, as if the truck is skipping or surging down the road. It changes with pavement types, and sometimes goes away or gets light without any thing being done. I have Ranchero 9000 shcoks set to 5 on rear, and 4 in front, and 70 PSI in load range E tires. Has anyone else had this problem? I am told the CrewCab has towing issues due to length and sagging, changing angle of attack on driveshaft, but others disagree. I had tranny serviced, in case it was slipping, but no codes, and fluid flushed, made no difference.
How can I make this thing tow smoothly??? Ideas? I am about to drag it back to dealer and trade it for GMC at this point, towing sucks with it.

 

I don't have the answer for you, but I would suggest posting this in the SuperDuty forum.

Welcome to the site!

Matt

 

You mean Rancho shocks, not Ranchero, right? Describe the surging in a little more detail. Is it in the engine, the braking, or the handling? Are you towing level?

 

How about some info on the gross loaded weight of the two trailers? You said the surging varies with pavement type and sometimes goes away or gets lighter. I'm just wondering if the hitch weights on the trailers are overloading your rear axle every time you go over a bump in the road, causing the surging motion from the extra weight of the trailer.

Is the gooseneck a real long heavy trailer? Are you carrying a couple horses, or a bunch of steers? Then you will have a lot more live weight shifting around. How big and heavy is the flatbed? Loading hay on a flatbed trailer might be pretty easy to get carried away with too.

Have you first tried temporarily disabling your brake controller, just to eliminate the possibility that it could be working improperly?

 

My guess is that the truck is overloaded, like horsepuller said, but I wanted to hear some more information on the "surging." An F250 may be too small of a truck to haul the load, but we'll see with more information.

 

I agree John. Definitely more info needed to separate a mechanical problem from a trailering problem.

 

Thanks for the replies everyone! Ok, the details are: F250 SD 99 4x4, V10, pulling a 3 horse Morgan gooseneck, unloaded. Today, we found out that the boost was on, and when it is off, it appears to be smoother. I have a Prodigy Tekonsha brake controller, professionally installed by the same outfit that did the gooseneck hitch. Rancho 9000 adjustable shocks are set to 3 on all four wheels, when set to 1 or 5 on rear, it causes the surging (as if the brakes are being tapped every second or 2) to be worse. The best setting is boost off, shocks to 3 on all four wheels, and 60 PSI in my load range E tires. The trailer has a dual axel setup with a GVAWR rating of 12,000 lbs, and I believe the empty weight is about 4,000. The flatbed is a 16 foot steel framed, wood bottomed, dual axel as well. When having problems it is loaded with 2 tons of hay (4,000) pounds. Today we got it to where it was really only surging between 25-35 MPH, and smoothed out the rest of the time to what appears to be the normal "surging" or "rocking back and forth" that I guess is normal when pulling a trailer that size. So I do not know if maybe the controller has a bad inertia sensor, causing it to try to lock up the brakes, or if the trailer is too heavy? There is no surging issue with the flatbed unloaded, but that is on a EZ lift hitch. The fact that the flatbed surges as bad as the unloaded gooseneck, sorta points to the boost on the brake controller being the issue, but I don't know why it happens at 25-35 mph with the horse trailer hooked up. I hope this is enough infor for you guys to maybe give me some suggestions. Thanks for your time.

 

From what you're telling us, it sounds like you think the trailer brakes may be activating. The Prodigy is a very good controller. The 'Boost' feature only gives the brakes more initial voltage, then scales up or down according to what the inertial controller tells it to do.

What angle is your Prodigy mounted at? It's supposed to be between 0-70 degrees. If it's at too steep an angle it might be throwing it off. (It's also supposed to be mounted straight, not at an angle or sideways.)

Have you tried pulling the brake relay or otherwise temporarily defeating the trailer brakes to verify if the problem is with the trailer brakes or controller?

If you can rule out the trailer brakes or controller as the problem, then you can try and figure out if it's something on the truck. Do you still have your old shocks you could try switching back to?

Scott

 

HorsePuller,

It is mounted at a 5-10 degree anle to the right of the steering wheel, in the little alclove they have there. Now, which brake relay are we talking about here, is there a seperate one that feeds the trailer that I could disable the brakes with to not activate? I was hesitant to do anything, as I thought any time the brake system loses power/signal, it automatically locks them, exactly how does that work, sice I know the breakaway does some sort of braking manuver, if activated, but it can't be a full lock up can it? Thanks for the help.

 

Also,

I do not have the old shocks. Someone had suggested that on the crew cab fords, that the application of the trailer applies so much weight in the back, that it shifts the angle of attack for the drive train, and creates some issues. They suggested the inflatable spring bags, but they do not fit in due to gooseneck mount. The only choice is a 1000 pund per spring helper kit I can bolt on the leafs in the rear to add support. I have not done this because it didn't seem to mathch the flatbed part of the problem. What do you think? Thanks.

 

I have an old truck, so I had to wire everything without the benefit of the pre-wired loom and relays like on the newer trucks. You'll have to get one of the SuperDuty guy's to help you find the correct relay. Or you could just unplug the Prodigy. I think your stop lamps and signals would still work. The Prodigy is made to unplug from the back and be put away for security.

Electric trailer brakes only activate when supplied with power. The break-away switch activates the brakes with a small 12v battery on the tongue, or in the tack room of the horse trailer. I think it's air brake's you are thinking of that default to lock-up.

About the shifting of angle of attack on the drive train, etc... I could sorta see how that might make some difference with an overloaded pull behind trailer, but if your loaded hay trailer correctly weigh's 6000# and the load and axles are balanced correctly, you should have about 600# of tongue load. Not that much, IMO. But I really have a hard time seeing that with a gooseneck hitch because it distributes the weight more evenly over both axles.

I wouldn't add any more helper springs, airbags, etc... until you absolutely nail down what's causeing the problem for sure. You may be spending money unecessarily and just adding more variables to the problem for now. That's just my opinion. Someone else may have a sure-fired answer to your problem.

One thing though: You don't have huge tires and a ridiculously high lift do you? Because if so, that changes everything and I don't really know what to tell you about that, except go stock. (Sorry, just had to ask. You probably don't, pulling a gooseneck.)

Scott

 

Scott,

Thanks for the reply, right now, I am tossed between a brake controller issue, an overload issue (although this is a 3 horse GN Morgan trailer, I fail to understand how it can be an overload, I have seen F150's with the V8 pulling them at shows), and a suspension issue in that order. The trailer itself has a GVWR of 12,000, but I believe it is at about 2500 empty.

We are thinking of trading the truck in if we cannot solve the issue, and I hate to say it FORD's service people suck! They want a burning wreck, or an error code before they can admit to any issue. I found 3 TSIBs related to problems I had with this truck, and I had paid the jerks for all three repairs to "find the problem", then each time bringing it back to "fix" the problem. I have a 100K mile Bumper to bumper warranty I bought online that fixes anything on the truck, (and it has worked great, I heartily reccomend it, as I made my money back on it, and they have never given me any problems)(cost 1200.00), but they can't pay till someone says it's broke, and why.

I am thinking of the GMC now, as the people I have talked to say their service is good, and the trucks better.

Thanks for all your help, I appreciate it. Great Board you run here.

PS: Everything is stock on the drivetrain (wheels/tires/etc). We bought the truck with 24 K on it after some "people traded it in after using it a year towing a travel trailer to the coast on weekends". I wonder if they got rid of it because of this problem? Hmmm...