Hey guys,

I'm posting this for my wife's grandfather, real nice gentleman who is still going strong in his late 70's. He's in town for Easter.

I was talking to him today about towing, as he and his wife travel all over in their 25' 7500-8000lb (fully loaded) trailer. He previously had a big suburban and never had any trouble. He went to a 08 Expedition and says that only when towing it has a symptom that I am calling surging for lack of a better way of describing it. it is a forward backward motion, at a fairly rapid rate. He said it is bad enough that it's hard to adjust the radio and his wife actually has to be convinced to go on trips now.

The guy is sharp as a tack and was an engineer for Northrop or another big outfit that helped build the rockets that went into space. Anyways, I'm still going to suggest he check mechanical stuff like the weight distribution hitch and make sure everything is tight, but I'm sure he's on all that.

I'm just curious if you guys have any other suggestions on what could be causing this? I found three threads on expeditions surging, but they were all happening without a load, I wonder why it would happen only when it has a load, unless something is loose.

Thanks!

Red
PS
I thought their tow capacities were pretty high, why are expeditions considered "light duty"?

 

You posted a question about a 2008 in the 2003-2006 Expy forum so that may be the reason for no response, but since it is probably not year related, I will give it a shot.
I would make sure that when not pulling the trailer that there is no missing surge issue. Find a steep hill and accelerate at mid-range and high throttle. If it runs smooth then it is probably related to the trailer he is pulling.
Does the trailer have surge brakes by any chance? If so, I would look at that first. It is very possible the system is badly misadjusted and causing this problem (it would also be rapidly wearing out the trailer brakes, along with over heating them and reducing fuel economy).
If it has electric brakes, I think some brake controllers are designed to apply trailer braking even if you don't touch the break pedal, but not sure.
Is he a two footed driver? If so, if he even touches the brake pedal while driving and the system has the sensitivity mis-adjusted, it could cause a problem like you are describing.
If it is nothing related to the braking, then I would recommend he take it to a reputable RV place and have them look at his hitch system.

 

Here is the 2007 and up Expedition/Navigator forum: 2007+ Expedition & Navigator - Ford Truck Enthusiasts Forums