3.5LAuto.160K.Upon start of vibration l downshift to 3rd (increase rpms) and vibration stops once l get out of speed band.Have not noticed any vibration during turns.When parked l rev thru entire range with no vibration. Any hints or ideas?

BALANCE YOUR WHEELS AND TIRES. EVEY 6000 MILES. THIS [SHOULD] GET RID OF THE VIBRATION.

first of all chrysler,jeep,and dodge are bad cars buy something else

Yeah.the car is junk.

IF IT VIBRATES AT A CERTAIN SPEED REGARDLESS OF WHAT GEAR YOU ARE IN THEN YOU NEED A WHEEL BALANCE!

Could be a tire issue, either out of balance, broken belt, or something else.

Also, it could be the inner tie rod bushings going bad. Those r known to go bad on those cars, & it will cause a vibration when they do go bad.

To check the tie rod bushings, u can check it by looking under the hood, behind the engine, & u can see the tie rod ends where they bolt to the steering rack & pinion gear. Have someone else turn the wheel & see if the bolts move before moving the tie rod ends. If they do, then u need new inner tie rods.
Alternatively, u can jack one of the front wheels up off the ground, & grab that tire/wheel & try to turn it (side to side, like making a right or left turn). If it has a lot of movement, then the tie rods r likely worn out.

If it turns out the tie rod bushings r bad, the best thing is to replace the entire inner tie rod, unless u have the local dealer install just the new bushings. The reason l say that is because the bushings they get from Chrysler need to be pressed in. Personally, l would just put new inner tie rods in if it was my car.

This could be a torque converter lock-up issue, If u have serviced the transaxle with the incorrect fluid, ( dextron) & not the ATF+3 or +4 , u will frequently develop T.C. shudder. This transaxle like all Mopar OD transaxles requires a highly friction modified fluid, ( some Import makers also require this type). When the TCM requests the TC too lock up it first partially lock up & this is when the vibration is most likely to appear. Thy this when the vibration occurs lightly press on the brake pedal, (just enough to make the brake lights Illuminate), this will signal the TCM to completely unlock the T.C. If the vibration disappears then this is the likely source of ur problem. When the clutch material wears it will fall off & could just be worn out, or the fluid has been in too long without a service, A good rule with these cars is to flush the system at 30K, then service the filter at 60K & again flush at 90K, continue this schedule until its failure. Heat is the #1 killer of these units, so what ever u do, do not run it low or overheat it by towing or overloading it, It will fail!