I have had a terrible vibration for over a year now. I thought it was a death wobble, also maybe a bad wheel. Well I just realized that the vibration comes when I am in overdrive and reach about 45mph and let of the gas. It starts vibrating like crazy. At first I could drive in 3rd gear without the vibration. You can tell that it really wants to vibrate but doesn't or not enough to tell. Now it seems once in a while it will also vibrate in 3rd and getting a lot worse in Overdrive. In my mind I don't think its the transmission. Feels like the rear end or gears or something. Any help on this? Thanks so much.

 

if you put the trans in neutral and coast a little does it go away or continue?

i have a similar problem, except on deceleration it's not a vibration but a humming sound. in overdrive at highway speed i have some vibes i'm pretty sure i can fix with shims. the humming is most likely my rear pinion bearing. check your pinion, see if it has any play. doesn't hurt to check the transfer case output too, see if it has any play

 

It totally goes away when I bump it up into neutral. Then comes back when I put it back in overdrive. I can also bump it down into 3rd but still feel a little vibration. Thanks for the info. I will do some checking.

 

In the line of "cheap and easy first", make sure you check the u-joints and slip yoke.
Tim

 

my humming stops when i shift in neutral too, to me it sounds like a bearing. please post an update if you find anything, i'd be interested to know

in my case i'm swapping the rear axle when i'm done cleaning the other one I have. hopefully that fixes it

 

I will definitely let everyone know whenever I have time to figure it out. Thanks for the info and suggestions.

 

UPDATE:

Update but not fixed. I had a mechanic take a ride with me and a look. Several of the guys there all came to an agreement that it must be the Torque Converter. They said it wasn't "slinging enough liquid". So I had them change it out with another one. Well no change.