Going by the title of this post I'm sure most of you are thinking warped rotors which is exactly what I was thinking at first, but let me explain. I have a 2000 Dakota 4x4, automatic, 4.7 with 120,000 miles. I've only owned the truck for about 4 months. When braking, I feel not so much a vibrating feeling, but more of a bouncy feeling in the truck at highway speeds only when braking. At first I thought it was the rear brakes because the feeling wasn't in the brake pedal or the steering wheel, it felt like coming more from the body of the truck. So I replaced the rear drums and shoes with new onces since they needed it anyway. I still have the same problem.

Now before I go replacing the rotors and pads, I just wanted to get some input. Usually when I've had warped rotors in any of my vehicles, I would only feel it while braking at highway speeds and not really at low speeds and I would really feel it in the steering wheel or brake pedal. With the truck, if I'm at a full stop, and just ease off the brake a little (no gas) and let the truck start moving on it's own power, I get that slight "bouncy" feeling in the truck. Once again, I don't feel it in the steering wheel or the brakes. I don't ever remember being able to feel a warped rotor at such a low crawling speed but it's been a while.

I'm wondering if it may be the calipers squeezing at different pressures and maybe need to replace those. Or maybe it is just the rotors and I should replace them and the pads. Any suggestions where else to look or what you might suspect is the problem? Or should I just eliminate the rotors as an issue and replace them and go from there?

Thanks
Joe

 

hubs? lift the front and see if you feel any wobble in the bearings. It's my only thought.

 

I have the exact same problem on my 202 Dakota, 3.9L 156,000 miles Replaced both front rotors, rear drums and cylinders. Nothing changed. Looking at front half shafts and hubs now.

 

Thanks for the info. i haven't had much time to investigate, but I did lift the front up last night and checked the wheels to see if there was any play in the hubs but they seemed fine with no wiggle. I also just replaced all 4 of the tires 2 nights ago. Not that I thought that it would resolve the issue, but I needed them bad. They were Goodyear Wrangler RT/S and the sidewalls on all 4 were bubbling.

I'm going to try the rotors next as it's only happening during braking and it seems it's my next logical step. Everything else looks OK. Maybe I'll just pull the rotors and have them cut if there's enough meat on them. If that doesn't work, at least it's not expensive to do. Although part of me is thinking maybe it's the calipers.

I hope you find the culprit as well. I'll keep this thread posted as I find out more

Thanks
Joe

 

The only reason I am looking at half shafts is when you brake the cv joints load up with torque and any play in them can cause them to load and unload rapidly maybe giving enough movement to cause the bouncing. Just a theory of mine. I have also replaced my tires, Bridgestone dueler AT's. I love those tires but it had no effect on the ride. Let me know of your outcome with the brakes, they caused no change for me.

 

OK, I found and resolved the issue. I decided I was going to change the rotors and pads just because it's at least a start. So before buying the parts I took off the front tire again just to take another look at the shape of the rotors and pads. Plenty of meat left on them and I didn't see any noticeable grooves or uneven wear. But that's when I got a better look at the outer tie rod and saw that the boot was ripped and there was barely and grease left inside. This was on the drivers side, the passenger side outer tie-rod was fine and still in good shape. I don't know if the previous owner replaced it but I'm thinking so since it still looked very good. Back to the drivers side, now I couldn't feel any play in the wheel when moving back and forth, but after taking the tie-rod out it was clear just how wobbly and loose it was. It didn't feel loose at all while it was mounted.

So I ran to the store and bought a new one and replaced it. Very easy job to do. It was the same exact size as the old, and I counted the turns taking it on and off, but I'm still going to bring it in for an alignment just to make sure as I don't want any uneven wear on the new tires I just bought. But after a test ride, no more shaking/bouncing while stopping at any speeds.

Thanks again for everyone's input and advice.