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Jtultra
05-30-2011, 10:03 PM
I have been getting a annoying vibration when I decelerate in 4th gear around 2K-2.5K RPM. It sounds like a bunch of bees are in my transmission when I let off the gas. It does it in 3rd too at about 2K, but not as loud as in 3rd.

I originally thought it was my stock drive shaft. I tried turning it 90, 180, and 270 degrees; no luck. I then had it rebalanced and the carrier bearing inspected. The bearing was good, but the balancing didn't fix the problem.

So I caved and bought this:
http://www.z1motorsports.com/240sx/product_info.php?cPath=651_929_947&products_id=3876
THE PROBLEM IS STILL THERE. Now instead of the buzzing inside the cabin when I decelerate, that vibration resonates in the new steel drive shaft and makes hella noise outside of the car when I let off the gas. It sounds like something vibrating on a sheet of metal. No, nothing is hitting the drive shaft and nothing else is rattling under the car. There is also no play. I also tried the 90, 180, and 270 degreed positions again.

From what I've been gathering through researching about this problem, the SR is prone to deceleration vibrations and a sprung OEM clutch is made to damper this vibration to keep it from resonating through out the car. So OEM is the way to go to keep this from happening. With my Spec sprung clutch, these sh!t heads sold me a clutch with springs that are either too soft or too stiff to dampen the vibration of my motor. This problem is supposedly more prevalent in tougher clutches like 6 puck clutches. Am I right?

So this is what I have that could be related to the problem:
- 93 S13 Hatch
- S13 Redtop SR
- Z1 Motorsports Stainless 1 piece Drive shaft
- Q45 Viscous LSD
- Spec Clutch (Forget what kind, I think the second step from their base model clutch)
- Koyo T/O bearing
- Nismo Tranny Mount
- Aluminum Sub frame inserts

So the thing I will NOT do in the near future: Pull the transmission and replace the clutch in HOPES i find the a clutch with the right springs. EFF THAT MESS. I'm sure many people would sympathize with me.

Now my next idea to subdue the loud metal rattling from my drive shaft is to fill my drive shaft with "Great Stuff" foam or the like and have it rebalanced. Through A LOT of digging I found that this has been a fix to some GM cars and 4x4s. I know this won't fix the problem. My goal is to minimize the noise without dropping the transmission again. Anyone heard of this before? Any other thoughts? Please discuss.....