45 MPH Rumble

[A.Sans]

Hi, this is something that's been occurring since a transmission rebuild.  Previously, I had to get my transmission (140,000 miles) internally rebuilt because it wouldn't shift out of second.  After the fix, however, there is a slight vibration when cruising at 45-50 MPH.  Enough to feel it slightly in your seat, feel it in the steering wheel, and hear plastic components rattling.  Above 50 and below 45 is where no vibrations happen.  Any quick ideas or possible solutions?

[onespiritbrain]

Does the vibration fade in and out? Or does it start as the torque converter locks, so it might start suddenly and then fade out as you speed up?

 

Also, is it only when your are pressing the gas and then it goes away when you let up? Or does it go away as soon as you press the gas and starts again when you let off the gas?

 

Does it vibrate the same around curves?

 

Also, what sort of vibration is it? Like vibration from a subwoofer or the bouncing of your knee when your bored/nervous?

 

 

[A.Sans]

1 hour ago, onespiritbrain said:

Does the vibration fade in and out? Or does it start as the torque converter locks, so it might start suddenly and then fade out as you speed up?

 

Also, is it only when your are pressing the gas and then it goes away when you let up? Or does it go away as soon as you press the gas and starts again when you let off the gas?

 

Does it vibrate the same around curves?

 

Also, what sort of vibration is it? Like vibration from a subwoofer or the bouncing of your knee when your bored/nervous?

 

 

Sorry for the vague description.  Once you approach ~45 it gradually appears to vibrate, continues to vibrate, and dissipates once you increase past 50.  Depressing the gas does not affect the vibration, nor does curves and other road environments (snow, rain, grooves).  As for the vibration, it's more of the subwoofer kind.  Like a game controller constantly vibrating or your phone buzzing.  You can feel it on the steering wheel and on your seat.  If there were coins in the cupholder, it would rattle slightly.

[onespiritbrain]

I suspect a driveshaft issue rather than a problem with the transmission.

Since they had the drive shafts out maybe there was a piece of crud on one of the mating surfaces when they put them back.

Or maybe they used an impact and one of the mating surfaces is wonky.