Shakes if i hit anything going faster than 50. Slow down under 40 it stops shaking?

possible a wheel alignment possibly from the rear wheels and loose/worn suspension rubbers

wheel bearing...... if it was an axel ur car wouldnt drive it would be loud in gear..

the smoke came from the spilled oil leaking onto a hot surface ( manifold) No problem there. The oil light coming on was probably from the oil surging away from the oil pickup in the sump momentarily allowed the oil pump to suck air hence a drop in oil pressure. To have all that happen, the hit on the curd was substantial. so I thinking bent axle flange and broken engine mounts could explain vibrations and engine shaking

Could be a wheel, tire, or axle shaft.
You could rotate the tires front to back and see if the vibration moves.
If it does the problem is one of the tires or wheels.
If it stays in the front, its probably one of the axle shafts. It could also be a hub bearing or something loose in the suspension. But a loose suspension part would normally show up when you hit a bump rather than on a smooth road.

tie rod end

Could be a tire out of balance, a drive axle, or something in the engine.
Is the check engine light on ?
Would it shake if you were coasting down a hill at 40 or 50 mph ?

Check your steering stability bar I had the same problem and it turned out that I had bent that bar.

The death wobble is basically when you are driving your lifted jeep down the road and the front end starts to shake violently. It can happen at virtually any speed, though mostly above 40 mph or so, and is a frightening experience, especially for those witnessing it for the first time. Now it doesn’t throw you off the road or anything … the front end just shakes. And the only way to stop it is to slow down and pull over. So it wasn’t that hard to get used to at first. But as it happened more and more, it seemed to get more and more out of control.

Hope help (remember comment and rated this).

If it shake only when the brakes are applied, then it is a brake issue/ uneven wear on the pads & discs.
There are upper and lower control arms, but if they are bolted tight, it shouldn't be the issue. If you hear clicking, check out you CV joints.
Have you rotated you tires? Patterns can wear in and cause lots of shaking.

chances are your shocks are worn out completely. replace the shocks with a good quality set and take it for a drive. cheers.

It sounds like you need a tune change at least the wires and plugs it also could be a worn or broke motor or tranny mount.