69CaliStang

Okay I have had the car for almost two years and it runs great and has had no issues until recently...

When cruising at exactly 72 mph I get a rather lagging vibration in the driveline... If i go to 71 mph and below or 73 mph and above it disappears. I have an auto and if I turn off O/D it reduces the vibration a bit but doesn't go away. Shifting into Neutral it goes away... Also I say it’s a lagging kind of vibration because it remind me of being in the wrong gear on a manual where you miss-shift down and instead of 2nd you get 4th gear... Any ideas?

Thanks in advance...

colbymh

Miles?? Possibly the u-joint (there is only one).

69CaliStang

Sorry I forgot to mention that! I only have about 6,500 miles on the car... I was thinking drive shaft / U-Joint or rearend... I have really babied her and have not abused it in anyway. Maybe I should!

Galaxie

sounds like there is something up with the driveline.

Take advantage of that warranty!

05GT-O.C.D.

Well, a wheel out of balance can cause vibes at certain speeds, couldn't a driveshaft out of balance do this?

houtex

You know, come to think of it... in the hot sun after work, I'd leave, and there'd be a similar sounding (feeling?) vibration at 70. It'd go away after a little bit. I figured it was the tires being flat spotted a teeny bit from Awesome sitting about, poor thing, waiting for me to get done with work.

If I was moving about from the two stores and/or other places, it wouldn't do it. So it hadda be flat spotting from the sittin'... or am I teh dum?

In your case, 6500 miles on a 2009 that was obtained in September of 2008, which means 270 miles a month, or about 67 miles per week, or 9 miles a day. That's a lot of sitting around in one place, I'm thinkin'. That's a lot of potential flat spotting, provided my theory's right.

In any case, yeah, you shouldn't baby her so much. They're made to be driven.

Shotokan1509

Thats only supposed to happen at 88 mph.

06GT

Maybe his flux capacitor is on the way out

69CaliStang

You guys crack me up... Would a flat spot really act like this though?

Maybe i will try a few things to isolate the issue a bit more and yes I know I should be driving it more!