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Vibration in the drivetrain

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Old 07-28-2006, 02:32 PM
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Default Vibration in the drivetrain

Howdy all,

I recently installed a new Dana S60 w/ 4.10s, Spohn tranny mounted adjustable T/A, and steel driveshaft in my car. Since the install the car has been vibrating quite a bit. It tends to vibrate a small amount around 40-45mph, but it tends to go away after that... until 60mph where it starts up again. From that point up it gets worse. At 120mph the car feels like it's about to fall apart.

The first thing I tried doing was taking the driveshaft back to the place that shortened it for me. They said the weights needed to be moved a slight amount, and they were. This made a very, very small difference. The issue is still 90% there still.

I have also tried resetting the torque arm a couple times. I back the car onto some ramps (rear only), slap an angle finder on the bottom of the bracket going over the differential, and then place it on the driveshaft. I then subtract the differential angle from the driveshaft angle. I have set it at -2, -1.5, -1, 0, and most recently -3. I have had no luck with this.

I soon plan to change the motor mounts (I very seriously doubt this could have any effect, but they need it anyway). Then I will have the new torque arm removed and cut so that I can use the inner bolt holes. I doubt that will make any difference. While it is off I will throw the stocker back on there to see if it makes any difference.

I anticipate that these steps will show that the torque arm had no effect and that the motor mounts will not either. What am I to do at this point? Go back to the driveshaft place? Consider possible problems with the Dana? If there are possible problems with the Dana, what in the world could they be that wouldn't cause other horrible noises and such?
Old 07-28-2006, 04:48 PM
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Did you just put the poly tranny mount in with the swap or has it been in all the time. Even if it was in you may have gotten used to it but now that you've upgraded everything??!! I know my car is an A4 but I replaced my tranny mount with the poly one (E.S.) when the stocker went bad as an upgrade plus it was cheaper. The car had a bad vibration using it. Then I took the preload plate off it helped a bit but I still had vibration at different times. I bit the bullet and bought the $71.00 OEM mount and it stopped all the vibration in my car. Others have had issues using poly tranny mounts as well. Mine was so bad that my knock sensor was pulling 17 degrees of timing out on the dyno when I went to have it tuned. Might be a cheap thing to try before tearing everything else apart. Plus with all the upgrades it might need a little more give. I could be completely wrong just thought I'd see if that helps. I couldn't beleive that the tranny mount was doing all that....I thought I needed a new driveshaft or a transmission. Good luck!
Old 07-29-2006, 09:47 AM
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Wow, thanks for the reply. I did put the tranny mount in at the same time. We left out the metal plate that came with it out. I really don't want to spend the money on another stocker, but it's certainly cheaper than a new driveshaft. I can't believe a tranny mount would cause so much vibration that your knock sensor was detecting it. That's insane!

Any other ideas before I follow Walking-dead's advice?
Old 07-29-2006, 12:28 PM
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i have the same prob as you. i am taking the ds back to have it balanced and try it again. then re-set the pinion angle. this sucks




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