RUMBLING (not Rubbling) Noise '95 Previa Alltrac SC

[kiowa]

I have a rubbling noise that starts around 50 and somewhat goes away at 60? I guest that it was the SADS, because I can roll the shaft a little left and right easily. In reading some of the SADS problems, no one mentions the speed at which a noise/rubble starting at a set speed. I'm not a tech, but I can read and follow directions. I have already replaced both front shocks, KYB GR2 and the rears, Monroe Sensatrac. Added an Addoc rear sway bar, boy does that help on my rural gravel roads! Also replaced the front differental, via my Toyota Shop Manual, Da Bible!! Updated the Stereo with an Eclipse AVN 726E and added wrecked Lexus Speakers from a 460LS. Always have my Escort 9500IX on ALL THE TIME! Any ideas on the noise/rubbling?? Thanks

[timsrv]

I'm not familiar with the term "rubbling". Let me guess, it's a combination of a rumbling & rubbing.........right?

[kiowa]

Has anyone noticed a 'RUMBLING NOISE" at speeds of 50 mph or higher? Doesn't really cause a vibration. What did you discover to be the problem? With the Previa being an echo chamber, it could be any place under the van. I've owned a Previa since they came on to the market in 1990 as a 1991 and have never heard this noise before. Thanks

[timsrv]

Sorry, wasn't trying to be a smart-ass, but rubbing & rumbling are 2 completely different sounds (just wasn't sure which one it was ). Still, even knowing which it is, there's a lot lost in translation from hearing the actual noise to reading a description in text. If you're not feeling a vibration, then my mind wanders to something affected by wind turbulence. Perhaps a loose inner wheel well or maybe one of those plastic splash guards that protect the under side of the engine. Lay down underneath and check to make sure these items are secure. That's all I can think of right now. Perhaps somebody else will chime in. Tim

[pdgizwiz]

A noise that happens over a range of speeds (or engine RPMs) is often due to a resonance . A machine like a car is designed to eliminate resonance but when things get loose, or parts put in place to dampen out vibrations that might trigger them fail, you can get weird shakes, rattles, and rumbles. Maybe even a rubbling. If your SADS is failing, or if the rubber mounts that the "Separated Accessory Drive" assembly are too stiff, too soft, or broken altogether, such weird things can happen.
It sounds like you know already that your SADS is bad, so I'd start there. To replace it you have to loosen the rubber mounts that hold the SAD in, so you can take a look at them to see if they are funky.
Engine mounds could be the culprit, too. They are designed to dampen vibration, but they are also designed to keep the engine in place even when they fail. So it's not easy to see if they are bad. I found that mine were bad when I took the engine out, and with new engine mounts, my car is smooth as silk. I didn't drive enough before this surgery to know how it worked beforehand, so I can't say for sure that the new mounts account for that. Generally I find that any rubber part on a 20 year old car should be scrutinized, and replaced if they're dodgy and if new ones are available. By the time a car is 25-30 years old, those parts may no longer be available anyway.