Question for the experts.

[D-Maxtim]

Yesterday on the way back from Florida pulling my 5th wheel (12,500#) up hills on I65 in Alabama and in Tenn. I experienced a strange surging or slight bucking in the Duramax. This was noticable enough that the little woman noticed it too. I had Juice level 2 (60 HP) tow/haul and cruise set @ 75MPH. Only noticed when in overdrive when truck shifted down the surge was gone even if I went faster than 75 while going up hill. I have 9000 miles on this 2003 3500. I am going to change the fuel filter as soon as I can this week. Any other ideas?

[RocketsDmax]

12500 lbs in overdrive up hills!? How was the trans temp? Not a good idea.

[sdaver]

sounds like the fuel filter to me too

[NETMINDER]

I'd guess fuel filter to. I'm guessing the down shift caused more fuel through injectors clearing the problem. But I'd change the fuel filter ASAP

[Lone Eagle]

At that weight and speed you have to be running 1200 plus on even the smallest hills. If you say not, I say get another EGT gauge. That is pushing it. Later! Frank

[zip]

If the truck isn't surging when the trailer is not attached, the bucking could be caused by too much hitch pin clearance in the hitch jaws. The trailer can move back and forth, pushing and pulling the truck. Check to see if the jaws are showing wear. I hope it's just a fuel filter, tho.
zip