From people I've talked to, everyone's rear end vibrates a little on WOT. Last night it seemed to get really worse though for some reason. The car has s03's and a clutch masters clutch, just for dignosis purposes. I know the tires when cold make the car ride like a log wagon but I had been driving for about 30 minutes and tires were plenty warm. Once getting into the rev's though it was vibrating worse than usual. I'm just curious if this is a major concern or something that everybody deals with. Why do our rears do this? I hope this is not a sign of some major problem arising like differential. I also had my diff fluid changed about 7-8k miles ago and just changed tranny fluid. Suggestions?

 

Is it only at high revs or is it speed-dependant? If it's based on road speed, it may well be the inner CV joints. I just had mine replaced under warranty/TSB. If it's at high revs in each gear, it's not anything in the rear mechanicals. It *could* be tire-related since high revs would apply maximum torque to the tread and scalloped tread blocks could be forced into a position where the vibration is more noticeable. If possible, trade wheels with someone for a quick test drive.

 

Get under the car and make sure the diff fluid hasn't leaked out the back of the casing. A buddy of mine had his changed by some idiot last month and they forgot to torque the fill bolt properly. The fluid slowly made its way out the hole and on to the exhaust and underbody. Needless to say clean up wasn't fun. He was lucky though. I don't think he suffered any permanent damage to the diff because he caught it in time. I think it still was about half full when he drained it and refilled it.

 

well i was just under my car putting my exhaust on that came (spugen) and the rear diff has not leaked fluid. It happens mostly and high revs and high speed, but not just high speed. The inner cv joints may be something, has 52k miles on the car now. I'll see how it goes today into my way to work. At high speed and lower rpm there is not a vibration.