CRXsir29

started doing it out of nowhere , at 40mph and above i feel a sort of shimmy/vibration as i accelerate but i do not feel it when the clutch is engauged, so that rules out a bent/unbalanced wheel or something, i also don't feel the shimmy through the steering wheel but it comes from behind me. Could this be something with my rear diff. All input welcome.

Thank You

negcamber

Have you lowered the car recently?

If so, you may have vibration from the cv buckets. You can either swap the cv buckets from right to left and vis versa (which is free, but time consuming) OR you can buy the 2-piece half-shaft spacers for about $175-200 (which save time, but at a cost).

CRXsir29

the car used to have coilovers but i returned it to stock suspension sometime last summer , so everything has been fine sense then till about 2 weeks ago or so

Tgr_Ree

I've had a similar problem and it was because my tires pressures were not equal. Check your tire pressures and make sure every tire is the same pressure.

Hope that helps.

negcamber

If the car had coilovers on for much of it's life, then the vibration is probably from the same thing that causes the vibration in higher milage cars who then are lowered.

See the explaination of what is happening in this thread:

https://www.s2ki.com/forums/index.php?showtopic=589724

CRXsir29

hmmm car was only lowered for about 6k miles

AznPup69

I had similiar problems before on my old Prelude. The steering wheel and car starts to vibrate once i get to about 50 mph. My tires were bad and after installing new tires and alignment, the vibration went away.

CRXsir29

hmm tires still have alot of life, i could use an alignment tho

MacGyver

Check for frozen brake calipers. I had a vibration show up that was indicative of worn inner CV joints, but swapping them showed they were practically pristine. After the drive home from the swap, I checked the rotor temps... three were nearly cold, one nearly burned my fingerprint off. It took me the better part of a day to rebuild the caliper (lots of rust from living up North), and I finished bleeding the system yesterday. Drives fine now, now vibrations.