MHGT

I have what seems to be a vibration at speeds above 85 or so......feels like the drive shaft has a slight harmonic feel. I have solid lca's and adjustable uca all poly bushings, hd adj pasnhard and 4.10 gears. I have checked my pinion and it is at about -1.5 degrees. Any ideas where it might be coming from ??
Also....is a one piece really worht it ????

alloutt

I also seem to have that vibration starts at about 80 but I really feel it at about 85+
I had all my suspenison installed at the same time but, I would think it is the additional NVH from the upper front strut mounts.

CBSTANG

Im not 100% sure on this, but I think from what I read your transmission pinion angle should be exactly the same as your rear differential. So that you are creating a straight line between the two, and it makes sense since your new one-piece doesn't bend like the stock one. But I have also read that some of the driveshafts are causing people difficulties because they were not ballanced correctly or because they try and use adaptor plates instead of switching out the rear flange. Anyway I hope this can help you, and I am sorry if I am mistaken with anything. Good luck!

UrS4

I don't think he has a one piece yet, that is his question.

Your adj UCA may need to be adj to correct your pinion angle. I have head the range is -1 to +3 degrees. Did you measure your pinion angle when the car was stock?

MHGT

No...never did measure the original pinion angle, But , in my mind the theory is to have a zero angle optimally at all times. But with car weight changes and load changes there is movement and thus the " range " .
I now have the -1.5 or so and that with the very limited suspension movement ( I have the shocks at 1.5 turns and it is pretty stiff...heck my wife won't even ride in the car :-) ) should keep me in my thoughts ideal.
Anyways...I am going to check to make sure the shaft is in the same spot as factory ..paint spots lining up tonight.

JimC

I have the one piece Shaftmasters aluminum -- ever since I installed it no more vibration. Prior to that upgrade I had really bad vibration. Great product you should check them out - they are a Forun vendor as well

MHGT

Looks like a cool driveshaft......did you use the adapter or not ? Did it make enough difference to warrant ?..... Did you notice a difference in acceleration ?

JimC

I still have the 7.5 rear end so didn't need an adapter, it was a simple in and out swap. My car also isn't lowered so I didn't need to change the emergency brake cable and don't need the new 3.5" shaft from Shaftmasters.
Yes, it made a definite improvement in the car, well worth the upgrade. The car feels much different than before, no vibration, very smooth acceleration, and the car is quicker. I went the track the day after the installation and set 2 of my fastest times for the year - which I then beat again a week later.
I had a friend in the car with me tonight to go to a meeting and he commented on how much different the ride in my car feels compared to his 2006 GT - which I'm sure is the driveshaft.