Faber

I would say it is most likely because their driveshafts don't vibrate.

seriously though, They can put a shaft on and check the runout, and balance if needed. We on the other hand rely on the seller to send us a perfect setup in the first place. There are some variables though. for instance a parfectly balanced shaft bolted to a pinion flange that is out of round will vibrate, and vice versa. I think spydershafts balances the shafts and then throws the pinion flange in the box and ships the product out. This assumes that the flanges are perfect, and could easily allow them to send out a combo that could be prone to vibration.

rony1976

Well, you are making a lot of sense right now... what can we do to get around that?

Oh, by the way, Bob at spydershaft saw my questions related to watt's link setups with an aluminum DS and he told me to give him a call. I would say awesome customer service for even a non-customer (since I haven't purchased the DS yet)!!

rony1976

Alright, correction, Bob at Shaftmasters!!! Sorry Bob, and thank you Bob for spending that much time with me on the phone.

Bob shared many stories with me, including that of someone that went through 4 gear installs in less than 2000 miles, all in the quest of eliminating vibrations and fixing the pinion coming loose. No success until the stock driveshaft was put back in place. 15000 miles later there are still no issues. The aluminum DS are truly designed to replace the stock ones when the suspension hasn't been heavily modified (I would venture to say that when the suspension hasn't been modified at all!). Anything adjustable pretty much doesn't match up well with the aluminum DS.

I was asking JDM's tech support if I could buy the watts without the saleen rear sway bar (since I have an Eibach one). They told me that when they put together these packages, everything is studied, and the best combo is probably using Saleen's rear sway bar with the watts link setup. I think the same concept applies to this. The Aluminum DS was developed under the assumption that it would be replacing the stock on, but no other suspension mods would be done.

I have to decide carefully my next mod then, since I already have Spohn's Adjustable LCA, BMR Relocation brackets, BMR's Adjustable Panhard and support. I was looking to replace the panhard and support with a Saleen Watt's Link system. Decisions decisions...

Bob, thank you again! Awesome customer service, beyond my expectations for sure!

shaftmasters

The story that I shared with Ron about the guy who went through 5 gear sets was someone who had a carbon fiber driveshaft(not ours since we don't sell them) and also had aftermarket upper, lower control arms and a watts link setup. He is an individual who has 6 cars that he races. He raved about the improved handling ability of his Mustang with the watts link setup and was dissapointed that his carbon fiber driveshaft didn't work with the suspension mods he had done.

Faber

Not trying to sound like a jerk or anything but I think to assume that an aftermarket aluminium driveshaft would be the only upgrade on a car that has a huge racing aftermarket is a little obtuse. Lightweight components (drivelines, flywheels, wheels etc.) are generally mods that are far down on the list for street/strip applications. Usually they are purchased by a more hardcore racer or enthusiast as a means to lighten the rotating mass, and knock tenths off of their timeslips. so to assume that a racer is not going to have upgraded components in order to for instance correct suspension geometry to compensate for lowering, or added components to reduce deflection and eliminate wheel hop is assuming a little too much. I just think there are some aluminum shafts out there that were either made on friday, or some of their components were. I think there may be a combination of things at work here. for instance ford put a two piece driveline with a CV joint in these cars for a reason, and that reason very well may be vibration issues with one piece shafts. the other thing may just be poor quality control. however in my case any quality control issue was outweighed by excellent customer service. I would bet money that the quality control issue is not an issue with spydershaft, but with dana spicer.

go-pony

Thanks to all who have added a lot of very useful info in this thread. I have had some recent NVH experiences with mods to my 2007 ROUSH 427R that might be of interest to people reading this thread. My car has the Steeda Stop the hop kit (LCAs, UCA); Steeda adjustable Panhard bar and brace, until recently the Steeda 1 piece aluminum driveshaft, Steeda CAI, BBR small pulley, pypes X-pipe, Centerforce dual friction clutch, and a custom dyno tune 430RWHP/390 RW torque.

The car was awesome until I replaced the 3:55 gears with FRP 4.10 gears . The reason I changed gears was that it was turning about 1900 RPMs in 5th @ 75MPH which required downshifts anytime I needed to accelerate quickly.

After the 4.10s went it the car developed a vibration at 80MPH that got really nasty at 90MPH, and I don't want to mention what it felt like at 120MPH. Also noticed a significant gear drone at 80 and above.

So back to the performance shop that did the gear install. They said it was the driveshaft. They said that they put the stock driveshaft back in and the vibration went away. I didn't get a chance to drive it, so I have to take their word for this. They couldn't explain why a driveshaft that worked fine with 3:55s would be wonky with 4:10s. I ordered the 1 piece steel driveshaft from ROUSH. Much better. Still notice a little bit of vibration at 85 and up. It is tolerable. The gear drone (I don't call it a wine because to me, a whine is high pitched, this noise is in the lower registers).

So the take away from my experience is: adjustable panhard bars, after market LCAs and a UCA, and 1 piece aluminum driveshafts can be a great combination with 3:55 gears. The car was smooth as silk, no vibration whatsoever. The same combination with 4:10 gears is an invitation to trouble.

I do have one question - can anybody tell me what might be causing the rear end drone at 85MPH and up?

06GT4RAD

I keep seeing this on various forums that when gears are switched the vibration becomes more pronounced. I have also read were the issue is actually with the Stock LS unit. Many have swapped out to the Detroit Truetrac or Eaton LS and the vibrations go away.

go-pony

This is the solution that I want to pursue. If anybody can point me to some info on deciding which of these to go with I will be very grateful.

rony1976

This would be great! Links, pricing and experience would be great too...