2005 4x4 2500 auto.

For awhile, probably a couple years, I have been getting a weird vibration when I am in 3rd gear only, light acceleration. Since I have a 05 I can't lock out 4th gear to diagnose it further. And actually I haven't done much checking on it, but I thought I'd ask if anybody has had this before?

I've had CTDs for awhile, so I'm not a total newbie. It's definitely not a ujoint, which have all been replaced fairly recently anyway. It's undoubtedly a trans vib, only does it in 3rd and is gone the second it shifts to 4th.

I don't know much about the 48re, think the bands needs to be adjusted?

Thanks for any help!

 

Sounds like an imbalance in the gear box, but it is certainly not the bands.