2006 Roadtrek vibration issue

[alwechs]

It's only noticeable when I'm driving down a STEEP hill at speeds above maybe 20 or 25 mph. When I brake, the whole van starts shaking and bouncing from side to side. Quite hazardous. When I slow down it goes away. I'm fairly certain it's not the brake rotors, my first assumption -- they brake smoothly, with no vibrations, and rotate easily through the calipers when examined by hand.

Other ideas? Bearings? Bad stabilizer bar? The only time this problem manifests is as described above. Otherwise drives smoothly. Shocks were recently replaced, FYI, as were front tires. Alignment was also done. Thanks!

[SteveWolf]

Start with having all four wheels balanced, rotated and the front end aligned. I had a wobble between 43 and 45 mph on certain roads that would creep up and often cause button biting. Problem solved.

[booster]

If it does it only on braking and at speed as low as 25mph, you are probably not looking at balancing helping.


Downhill steep hills, Chevy Roadtrek, and severe pulsations often called juddering is very commonly caused primarily by the brake pad material and secondarily by the the rotors that get unevenly coated with brake pad material.


Lots of threads on the topic here on this program, but condensed version is to use the best semi metallic, not ceramic, pads you can get. There are brand, model, part number recommendations in the other threads. Secondarily either replace the rotors with upper quality level ones, preferably smooth or with small slotting. Drilled and slotted are not really as good in this case, or have the runout on your rotors checked and if within .004" sand the surfaces well to remove all of the old transferred pad material on the stopping surface.


It is a very common problem that we now have enough information to be able to fix quite readily in nearly all cases.