I know I'm late to the party...but I'm no longer on the sidelines regarding the Spydershaft install. I purchased from one of the vendors running a special and installed it this weekend.
Since I've had my rear end done under warranty three times, I did it the anal retentive way, using Ford's work instructions for a pinion flange r/r:
http://s197forum.com/forum/attachment.php?attachmentid=624&d=1177902338
Install would have gone a lot faster if I had not got hung up on the driver's side brake caliper which ended up needing to be compressed and bled, but other than that and a sore arm on about five attempts at the pinion nut with a breaker bar, the install went fine.
I borrowed my dads digital torque meter to measure the pinion bearing preload and pinion nut torque before and after the pinion flange install. It has a nice peak read function on it so all you have to do is grunt and muscle the nut off and then go check the result on the meter.
For those looking for reference points for their own installs or just curious:
My peak torque on the pinion nut was 195.6 lb. ft.
Pinion bearing pre-load was 1.3 - 1.5 Nm or about 12 lb. in.
(the meter only reads 20 lb. ft or higher, but could read to 0.1 nm)
On the pinion nut reinstall I nailed the pinion nut torque right back at 195.6 lb. ft. The pinion bearing preload was also right back at 1.5 nm.
I'm running H&R sport springs, which is the least drop you can get: 1" on the front .75" on the rear. I'm not running an adjustable UCA, and measurements on my operating angles, while not
perfect are within Spicer specs.
Due to other commitments and plain apathy towards the vehicle regarding the pinion nut removal, I did not drive it until two days later (that let the red loctite dry, though). I am happy with the results. The car just feels "lighter" on acceleration and the clutch at low RPM's doesn't feel like it has to catch a boat anchor.
And after three years of chasing it, (the aforementioned 3 ring and pinion installs), the whine at 55-65 is GONE!!! The whole time it was that piece of crap stock driveshaft. Score one for the Buzz.
Thanks to Ron for the invention of this nice mod. Cheers!