05' Ram 3500 4x4- experiancing low speed shutter (pretty excessive) 20-25 mph (not faster, not slower) Tires are new, not gear related happens in 2, 3 or 4th but only @ 20-25mph. looking for suggestions? Will do it with or without load.

 

Are all 4 tires new and the same tread pattern?
Did the tire shop accidently put one of wrong size on?
Match the air pressure in all 4.
Check lug nuts for proper torque.

 

Other than what the Capt. said, I assume that the problem came about as soon as the new tires were installed. I had a similar experience and with new tires as well. After the first balance, one tire slipped on the wheel (too much install lubricant put on the rim) throwing balance way off at any speed. Second and third balance didn't fix it entirely, even when load balanced. I apparently had a bad tire(s). Got a new set and now all is fine. If the tire shop can't get it right, have them swap out the set. Discount Tire did it for me without any hassles.

 

The early dodge trucks had a driveshaft problem, ck and see if the center bearing of the driveshaft is causing your shaking.

 

The exact same thing happened on my 2004 dually 6 speed. It turned out to be universal joints on the main drive shaft. Now I've changed them it's all as smooth as silk.

Mine was so bad at one point it nearly shook the mirrors off but above 20mph it smoothed out. I changed all the joints, the ones on the front shaft also which are a real PITA but the ones on the main shaft were the worst. I took one apart and lots of rust and dust fell out on the bench! According to the service foreman in my local Dodge dealer this is a common problem caused by the fact that the factory UJs are "sealed for life", in other words you can't grease them. He told me to get some aftermarket ones which can be greased and as I have no warrant left, I did.