1990 Dodge Dynasty runs great, even after 270k miles. Only unusual problem is that their is a front end shimmy and I can't find the cause. Wheels and tires are fine... cv-joints(axles) seem to be fine motor mounts seem in tact... what the heck is going on here?! Any ideas or suggestions?

If you have had tranny work recently, the mounts and the axles may look ok, but there's a good chance that the driveline angle is off and that's why you have the vibration.

Worn shocks/struts, or any other parts in the front suspension can cause the problem. After 270k, it's likely time for some replacement parts.

I have a 94 Dynasty with the same problem. I love the car it runs great, it's fast as hell, but the same thing with the front end sounds like its gonna shake apart when you hit a bump or rough spot in the road.

i had one in the shop like that, found out the upper strut bearings were bad allowing struts to move about