| Wall of text warning! After ~20 months of dealing with a persistent vibration around 40 mph, I finally resolved it by installing a one-piece carbon fiber driveshaft. I believe the center support bearing (CSB) was the cause of this subtle vibration all along. Even in brand new, perfect condition, I think the CSB transmits a baseline level of NVH into the cabin that causes the 40 mph vibration. It also seems this is a more widespread issue than I originally thought — I’ve included some screenshots below from posts around the internet showing others dealing with similar problems. The vibration was most noticeable around 40mph, particularly while decelerating to that speed. It would disappear at higher speeds but return around 80mph, with the cabin vibrations becoming more intense as vehicle speed increased. It was also very difficult to pinpoint — at times it seemed like it was coming from the front wheels or behind the dash. It's worth noting that Nissan eliminated the CSB starting with the 350Z and switched to a 1pc carbon-composite driveshaft — further evidence, in my opinion, that there were NVH-related issues with the CSB on the Z32. Additionally, OEM CSBs are no longer available; only aftermarket options remain. The issue began when I replaced the CSB on my OEM two-piece driveshaft in July 2023. What was intended as simple maintenance turned into a problem: I unknowingly misaligned the yokes on the front half of the driveshaft during CSB installation. This caused a noticeable vibration that wasn’t present before. Thinking it wasn’t an easy fix, I installed an aftermarket two-piece driveshaft. (Shout out to Doug71zt(CAN), who correctly diagnosed the yoke misalignment in the thread I made: La-Z-Link(Takes forever to load because of img host, but it will)) The aftermarket driveshaft, having properly aligned yokes, eliminated the major vibration — but I still noticed a subtle 40 mph vibration. It took some time to admit to myself that it felt slightly worse than the healthy OEM driveshaft felt before my yoke mistake. I suspect this was because the aftermarket driveshaft used smaller diameter tubing, which is more prone to transmitting vibrations (which are going right in to the CSB). Smaller tubing has less mass and less resistance to harmonic frequencies, even when properly balanced. In contrast, larger diameter tubing — like the OEM driveshaft — naturally resists these vibrations better, which likely explains why the aftermarket two-piece felt subtly worse compared to the OEM driveshaft when it was originally healthy. After over a year of running the aftermarket two-piece and replacing every component of my suspension trying to chase this vibration, I had no other option but to try the OEM DS again. So I switched back to the OEM part, with a new CSB and correctly aligned yokes. I was shocked at how much better it felt compared to the aftermarket one. That wasn't the end of it... Even though the OEM driveshaft felt way better, the subtle vibration was still present — the least bad it had ever been, but detectable. This was so bizarre because I've run this same driveshaft setup since 2008 with my old Z, why is this bothering me now?! I believe the vibration was always there but subtle enough to ignore until I started paying close attention. I suspect most people experience it without noticing or being bothered unless they are highly sensitive to NVH. The next attempt at a fix was installing an aftermarket CSB mount from JXB Performance. Their kit involves shaving the rubber off the OEM CSB, leaving only the bearing, and then sandwiching it between the two halves of the JXB mount. The product has strong reviews on other vehicles and platforms, and I was confident it would finally solve the problem. I modified the CSB on my aftermarket driveshaft (to avoid damaging my OEM shaft). Up to about 50 mph, the results were promising. However, above 60 mph on the highway, the cabin vibrations became extreme. I was stunned because the results were the complete opposite of what I was expecting, and it felt fine at lower speeds.This experience really cemented my belief that the CSB had been contributing NVH into the cabin all along. Perhaps if the Z32 chassis were more reinforced at the CSB mounting point, the rigid JXB setup would work. I’m confident their product works well for other applications, and I was satisfied with the support I received returning the part. Driving home with the car feeling like it was going to come apart made the next step obvious: try a one-piece driveshaft again. Over 10 years ago, I briefly ran a steel one-piece driveshaft but found vibrations were worse compared to the OEM two-piece with CSB. I know you can try clocking the install position of the DS, but it is a lot of work without guaranteed results to find a "good" position. That experience made me wrongly believe the CSB was necessary for NVH control. At first, I was only considering a steel or aluminum 1pc driveshafts again, but ChatGPT convinced me to consider carbon fiber if NVH was my top priority. I had always dismissed the carbon fiber drive shaft as being too expensive and only for extreme builds. I've scrolled by it tons of times on CZP's site thinking "Who's buying that?" But after all the time and money already spent trying to resolve this issue, it was me who was buying that! $1,600 later and over a month of build time, the carbon fiber driveshaft arrived and finally resolved the issue. After a month+ of driving which included a 6 hour road trip and total of 800ish miles, I've been really impressed with the results. The 40mph vibration is finally gone, and accelerating from 80 to 100mph now feels nearly identical in terms of NVH to accelerating at lower speeds (20-40mph). Highway cruising 80+ is noticeably smoother and more comfortable too. I’m really happy with the carbon fiber driveshaft. I extended my stock heatshield to protect the investment a little more. I had to beat it into shape with a valley for clearance, so it looked rough after installation but functions properly. I may try to fabricate something cleaner in the future. If anyone is interested in my old aftermarket two-piece driveshaft for some reason, send me an email with an offer — I’d like to move it. Trying a new image host as well... Newly received CF DS Goodness
 New CF DS vs OEM 2pc vs Aftermarket 2pc w/ shaved CSB
 JXB CSB installed
 Poverty extended heat shield
 Here are some interesting posts from around the web, all sharing similar experiences. Tons more posts about z32s and 40mph vibrations too, below is just a small sample. 
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Center Support Bearing or Center Support Burden? - 
