I already ran it with the rear driveshaft removed and it was smooth. I had already ran without the front but that didnt help.

The mechanic at the shop tried claiming my line pressure was low and that either the sun shell or tranny output bearing was bad. That just doesnt add up. I'm going to take the rear driveshaft to get balanced and u-joints (although new) checked.

Were the yoke ears damaged when the u-joints were installed? Unless physically damaged the driveshaft should still be balanced. Are the u-joints the correct part number and mounted (centered) correctly?

The yoke ears appear to be fine. I wasnt thrilled with the u-joint installation (one shop thought there might be some play in the new joint) so I'm having them checked at a shop the does nothing but driveshafts. I was leary of that diagnosis because the old shaft also vibrated. The old shaft had its own issues so I picked up the used shaft and had the u-joints replaced. I figure if the balance is checked and corrected and u-joints are confirmed good then I'll have to continue looking elsewhere.

Just wanted to let you know my issue was the aftermarket transmission mount. I took it back to the shop and *****ed to them. They compared it to dealer mount and the aftermarket mount was too high so they fixed it.

Going on what you said and the fact that this all started with the new mount (anchor brand) I replaced the tranny mount tonight with a genuine mopar part. Its now running perect! The vibration in reverse and after hitting bumps was so bad I stopped driving until the part arrived. The parts look the same but if you look at the bracket that holds the exhaust, it has a small nub sticking out of it to help line up the parts. The mopar part has a hole to accompany this and the anchor part does not making it impossible to bolt the mount squarely to the bracket. I wish I had noticed it the first time around. Lesson learned! The mopar part was $100 more but worth every penny.

https://cimg5.ibsrv.net/gimg/www.che...3566d7e9a4.jpg

Is this the transmission mount? I was under mine today searching for leaks. Took this picture to identify what it is. Feels kinda squishy.

Yup, the rubber deteriorates over time. I was able to rock the tranny back and forth quite a bit by hand and it made all kinds of creaking noise. I got my mount from moparpartsdeals.com for $140.

Geez, that's expensive!!

Is that a hard job to do?

Change the mount? Not at all.

Got a floor jack?

Yes I do. I was just curious. I don't think mine is in need of being replaced at the moment, but I may decide to replace it at some point anyway.

If all your bolts come out its less than an hours work.

You're good to go then. All depends on how much penetrating oil you need based on where you live.

That was the cheapest mopar part I could find. Money well spent to have a vehicle that doesnt vibrate.

Agreed. vibes/squeaks/rattles drive me nuts.