Short Bed Ext. Cab vs Long Bed Four Door

JIMNLIN wrote:
Something with the combo isn't right. A new longer wheelbase truck may or may not fix the "squirmy" feeling.
Your extended cab short bed has a 140" wheel base and should have no problems handling a 8500 lb dry/ 10k wet weight 5th wheel trailer.
Other things I look for causing "squirmy" feeling pulling a GN/5th wheel trailer is;

Too much tire pressure in the front and rear truck tires...causes the tire to roll on the center of the tread and will wonder all over the road.

Aggressive all terrain tires and mud terrain tires with those large lugs and voids can exhibit tread roll..... feels like the tires are half flat.

New tires on the truck can have a bit of tread roll also before their broke in.

Truck and or trailers suspension not aligned properly.... the truck/trailer simply will not track each other.

Bias ply tires on the trailer also may not track the truck with radial tires.

The trailers tires has too much air pressure .....tires rolling on the center of the tread won't track the truck.

The truck wheels too narrow for tires like a LT265/75 or 285/75 on a std 6.5" GM wheel can roll on the center of the tires tread.....causing handling/tracking issues. Many GM owners myself included have had this happen.

Now if the truck is squirmy cause it makes a great story to tell the wife so she will want you to get the new truck ....then heck yeah go for it :B

Haha I love the last comment! And I don't have to convince her unfortunately, I have to convince myself! It means the 700hp Coyote Mustang goes bye-bye, and that will be a sad day for me. You pointed out alot. I'm wondering if its tires. I've actually got BF Goodrich All-Terrain tires that have less than 1000 miles on them, and are a 265/75 on the stock GM wheel. I thought maybe it was a 7 or 8" wheel, but it must be the 6.5" you referred to! I know I have 65psi in the front, and 80psi in the rear, but the other points you pointed out might be worth looking into! I'm going to make another trip in a couple of weeks and might try to pickup a little tongue weight too. My tongue is barely 15% of the overall weight (1274 tongue, 8408 dry), and loaded might be less than 15%. Dont I need to be between like 15%-25% with a fifth wheel or something? I forget where I read that, I just read its more than a bumper pull.