Intermittent, subtle "vibration" from the rear?

[sqd]

Ok, bad title, but I have no idea what else to write. The problem is, that when driving on a smooth road, it feels like my rear wheels are driving over an uneven surface, kind of. I can feel it in my lower back, ass and legs. Nothing from the steering wheel or anything that would suggest it's from the front. All senses are pointing to the rear.

It's an intermittent kind of subtle shaking or vibration, not rapid but yeah, like the road is cracked, but only for the rear wheels. I've been through three sets of wheels/tires and had stock struts and coilovers on, stock LCAs and my ISC ones I have now. Same thing. I've had an alignment too, still there.

Can it be the diff? I've never replaced the oil in it, if that makes any difference. Car is a '13 with little over 15k miles. Anyone have a clue to what it might be? Or is it one of those things that is my nightmare - no one has any idea what it is

[ryoma]

are your wheels properly balanced? maybe a wheel weight fell off?

[sqd]

Originally Posted by ryoma

are your wheels properly balanced? maybe a wheel weight fell off?

I don't think I've managed to lose a weight from three different rear wheels I've had the stock wheels and two sets of aftermarket ones. They been balanced, so I don't think it's that.

[churchx]

My first bet would be wheels inbalance aswell .. but OP striked out that with mention of rebalancing on tire remounts .. but still, that feel description sounded like when i went to track race and didn't cleaned up from wheels uneven lumps of ice/snow inside .. = bad vibrations when speed got to 70-80kmh and above.

Check what else is rotating and may get inbalanced. Driveshaft? Brake disks?

[sqd]

Originally Posted by churchx

My first bet would be wheels inbalance aswell .. but OP striked out that with mention of rebalancing on tire remounts .. but still, that feel description sounded like when i went to track race and didn't cleaned up from wheels uneven lumps of ice/snow inside .. = bad vibrations when speed got to 70-80kmh and above.

Check what else is rotating and may get inbalanced. Driveshaft? Brake disks?

Thing is, I wouldn't call it a "vibration" per se, that would mean it would get worse and go up/down with speed, and I don't think it does, not exactly.. Sure, you can feel it a little more clearly at higher speeds, but not like it's something that is rapidly increasing with speed. This is driving me crazy NOW because I can't clearly explain it :/ If it was a vibration like a warped disc, it would have a predictable and clearly repeating vibration "pattern", this is slightly random more than it is constant and identical.

[humfrz]

You might check to see if the rear calipers are tight and the brake pads are seated properly. Also, while you are there, check to see if the emergency brake shoes are set proper.


humfrz

[nickmerronesucks]

I may have the same problem. mine is more of a vibration noise when letting off the throttle. was wondering if it had something to do with all the solid bushings i have in the rear though and noise transfering.

[JazzleSAURUS]

If it's between loading and unloading the driveline, I've noticed this at lower speeds, and occasionally on super smooth highways during a pull. I think that this *might* be related to the voided bushings on the rear diff, so I'm considering the whiteline positive traction kit.

That's a lot of movement and clunk.