A few months back I installed a new Carbon Fiber driveshaft in my GT500. I've been testing it over the previous months to make sure it does not have any vibration problems. Due to its innovative design, I've found no issues even at 130+MPH in 5th gear. This driveshaft does not have any of the vibration issues common with most one piece driveshafts on S197s.
The first step is to get the heavy stock two-piece driveshaft and carrier out of the car:
You'll be reusing the four front bolts, they are a 12pt 12mm head.
Be careful not to strip out the rear six bolts which will be reused as well, they are a 10mm head.
The stock DS weighs over 40lbs:
The new carbon fiber PST shaft weighs under 15lbs:
A nice reduction in rotating mass.
Up front the new CF driveshaft bolts up to the stock flange:
In the rear the CF driveshaft bolts up to the stock style cup flange and does not require a different pinion flange like some driveshafts.
You can now see where the PST driveshaft is different, they use a heavy duty CV joint to account for slight changes in length as the axle swings through its arc of motion, this is exactly what Ford uses on the OE driveshaft. This one is much thicker than OE though. Most aftermarket driveshafts use a slipyoke at the rear of the driveshaft, which is what ford got away from when they built the longer S197s, probably due to the same vibration issues that the aftermarket is experiencing with that style of shaft. IMO I've had many cars on the dyno with shafts that were not supposed to vibrate, but they still shook at high speeds, its an inherent design isssue with te slip yoke that no ammount of balancing can fix. You may be okay with a slip yoke at 80-120, but if you do any high speed driving or dynoing the vibration can show up at 120-180mph, I once had a car vibrate so bad it broke the speed sensor on the dyno drum.
I'm now carrying these driveshafts on my website, due to the limited amount of length adjustment available in the CV joint, each car should be measured from the front flange to front edge of the rear cup with the suspension loaded. This can be done very easily with the car on the ground by one person with a tape measure that has a magnetic tip.
Carbon fiber also has some inherent benefits in that it reduces shock loading on hard launches & shifts.