I've heard that these trucks are supposed to be pretty smooth, but apparently no one told mine that. It's a 2001 Durango RWD SLT Plus with the 4.7 L. It's gotten progressively worse over the last 2 years I've owned the thing. I feel a lot of the road underneath the truck, and it takes speedbumps and potholes way rougher than I know it should. I know it probably needs new upper ball joints/control arms because I can wiggle the front driver's side tire a little when it's jacked up (the tire is mounted to the hub just fine), and the tires won't align perfectly, but I know that can't be the only issue.

Things I've replaced so far:

Rack and pinion

Inner and outer tie rods

Rear tires (now running 255/70R16 Valera H/T's, front tires are Cooper 255/65R16's that are about to get replaced with tires identical to the rears, and none of the tires are running too high of a pressure)

Lower control arms (both sides)

Front and rear shocks (running KYB Gas shocks)

Two front wheel hubs, one rear

What else could be going wrong? I can't tell if the rear leaf springs or the front coil springs are bad, how would I determine that? Could it possibly be the body bushings? I was at a loss after I replaced the shocks and there was no difference. Any help is appreciated.

Cant help you much with the isue,except to confirm that these cars are not supposed to have a rough ride,my 2000Durango 4x4 with a 360 is a nice and fairly smooth ride,not as smooth as the Benz on highways that it replaced but certainly far far from a rough ride.

Keep at it and replace worn out parts and look for worn our or even missing bushings and balljoints and im sure you will find the problem.

Maybe this ought to be in the trucks forum? Likely to get more relevant responses there.

Not a big fan of KYB shocks. Their high pressure gas combined with divergent valving means they have a very narrow window of optimum operating range.

Springs support the vehicle and determine how much resistance is offered to dips, bumps, cornering and load. Shocks determine how quickly and efficiently/smoothly the springs react to these changes.

He doesn't say what kind of KYB's. Monomax, GR2 and Gasadjusts are all available.

Bilstein shocks worked well on the wife's Dakota R/T

They're KYB Gasadjusts

Well, those are the stiffest of the KYB's.

I'd of just got a set of Monroes or similar.

Wish I'd known that before I bought them and put them on. Oh well. Still though, I would have expected at least *some* improvement versus the old stock ones that I took off (that had been on there for over 140,000 miles).