Clunk, clunk, clunk says the big, red Dodge

[Matt Harwood]

Even though it's not old-car related, you guys are the smartest car people I know, so I thought I'd give you a crack at my problem. FYI, the truck is a '98 Dodge 2500 HD 3/4 ton, 4x4 extended cab, long bed, 8800 GVW, so it's HUGE and heavy. Basically a dually without the double wheels.

This morning on the drive to work, I noticed a clunking sound through the transmission tunnel (though I don't believe it is the transmission or transfer case--the floor shifter for the 4WD is just the only hole in the floor). It is related to speed and gets faster as I accelerate. After about 30 MPH it either stops or I can't hear it anymore.

Here's the weird thing: it stops when I apply the brakes at any speed.

Here are my thoughts:

1) Driveshaft U-joints. I know they're bad, and I'm going to replace them soon. Clunking might stop during braking because the driveshaft is now being reverse-loaded (i.e. driven by the rear wheels to the engine instead of engine driving the rear wheels).

2) Brakes. Although everything on the front end is new (hubs, bearings, front axle U-joints, rotors & calipers), the fact that the noise stops under braking suggests that perhaps something in the brake system is farked. Recently I had one of the rubber bushings in one of the calipers work its way out, although that only make a metallic thud when i went over bumps as the caliper bounced on its mount. I think it warped the rotor, too . That was on the left side and this sounds like it's coming from the right.

3) Front U-joints. Perhaps I screwed it up during the install? I had a shop press the old ones out, but I reinstalled the new ones myself. The shop didn't mark the axles when they took them apart, so it's possible that one of them was installed out of phase from original.

4) Front tires? They're pretty shot. Although they have a lot of tread left, I can see substantial cracking near the rim on the inside. They're going to be replaced sooner rather than later.

Something else? Suggestions? I'm going to put it in the air this weekend and put it in drive and see if I can find it. But if anyone has thoughts, I'm all ears.

Christ, I'm sick of nursing this truck. For something that's supposed to be heavy-duty, it sure is fragile. Sorry Mopar fans, but I'm done with Dodge forever after this one dies.

[Barry Wolk]

Your assessment of the u-joints sounds like the most likely cause.

[Dandy Dave]

I had a 1997 Dodge One ton van once. It was the worst vehicle I ever owned. The rear end made noise. The tranny would not shift into overdrive. AC did not work. heater only worked on high. A lot of other small problems, and it had far less than 100,000 miles on it. I agree, Dodge built absolute junk in those years and I think I read that 97 was about the worst year! Dave!

[CarlLaFong]

95 Ram dually Cummins. 250K Rebuilt the starter and alternator. Other than oil, filters and brakes, that's it. The paint has "Dodge leprosy" and is peeling. Thanks EPA

[Dave@Moon]

The paint on my 1996 Ranger (which has never seen a garage in it's life) is nearly pristine. <span style="font-style: italic">Thanks EPA!</span>

(I did just have to replace the 12 year old original battery, though. The only real repair it's seen in 70,000 miles--although it does need a new wiper switch.)