The Dodge Challenger Message Board

Here's an update. It finally stopped raining.

Got the motor bracket replaced, settled all the mounts, including the cross member, even messed with the tranmission alignment a bit.

Now i just have to grade the road and let things dry a bit to check her out.

Well, the vibration at 2500 RPMs is pretty much gone since settling in the motor and trans mounts. Not sure if re bolting the trans to bell-housing did the trick or now though. It was indexed and has a collar so only minimal alignment change was possible.

Still a little vib at 65-70 MPH so I plan to rotate the drive shaft in the Yoke.

let me know jon , cause thats about where my vibration is on the top end at higher speeds,its kind of a harmonic/up and down vibration, keep me posted

Same thing Drew, an oscillating vibration in tune with the exhaust it seems.

from reading all the replies i think it is driveshaft balance. Rotating 180 is always a good start, but i can't see anyone has mentioned getting it professionally balanced (if they have, give me a kick). There are factory balancing weights and after disturbing the factory setup in whatever way, sometimes nothing can be done except a rebalance, where they knock the weights off and reweld on new ones after running it up at speed

Goldenblack440 wrote:from reading all the replies i think it is driveshaft balance. Rotating 180 is always a good start, but i can't see anyone has mentioned getting it professionally balanced (if they have, give me a kick). There are factory balancing weights and after disturbing the factory setup in whatever way, sometimes nothing can be done except a rebalance, where they knock the weights off and reweld on new ones after running it up at speed

After picking up my car I found she had developed a bad vibration at 65 mph ,so checked the joints and found a little slack. So changed the front joint and had it balanced and now she is great,the guy that did it said Dodge only balanced them to 55 mph when new. I don't know how much truth there is in that though