The rear tire is on tight but it wobbles and shakes the whole car when i drive it. it has good tires on it.

get that wheel (etc) inspected, end fear.
make sure nothing there is loose now,
in real auto repair shop or suspension shop.

How old are the good tires? These speeds usually mean belt or balance problem with tires...If new tires, they need to be re-checked for balance...and not out of round...also check for bent wheel...due to chuckhole? Sometimes a bent steel wheel can be hammered straight...hope this helps.

If steering wheel shakes bad tire on front. If whole car shakes bad tire on rear. Or tires could be out of balance. If steering wheel shakes when brakes applied, front rotors are warped.

sounds like a bent axle

One of your rear tires busted a steel belt in the tire. It usually causes a hump in the tire when this happens, causing the wobble

you need to balance your tires

I would call this 1 of 3 possible problems.....

This first could be a bad or unbalanced tire. Sometimes the multiply ties we use on cars separate between layers, this causes an un-natural bulge that can not always be seen, but certainly can be felt while driving. This is called ply separation. An unbalanced tire, which could be caused by a wheel weight falling off, or a shift in weight that could be cause by something like an impact break or the ply separation, would also cause a wobble that varies at different speeds. The best way to check it out without a shop visit, is to take the wheel off and just inspect it, make sure everything is smooth and even.

Secondly, a wheel bearing could cause a wobble as well. The self test for this is to jack the car up, leave the tire on and wiggle it. It should feel tight all the way around and not move up to down, or side to side. A way to test this unit while driving, which is not always accurate 100% but will give you a clue as to where to look first is drive in an area free from other traffic, when it starts to wobble, turn to both the left and right without touching the break. If the wobble goes away it is likely the cause.

Thirdly the ball joint could also cause a slight wobble. To check this, I usually jack the car up, do the same wobble test as described above, then remove the tire and inspect the joint. A good joint will have absolutely no tears in the boots. It should also feel solid at you try to move the other components that surround them.

Good Luck, we are here if you need anything further.

Well the frist thing to do is have the front end checked it may have worn parts, like a tie rod end or a balljoint. another thing it may be is a bad tire ive seen a bad tire do this also, a tire with a bad belt would also cause this so check tires for out of round

Jack front end. Use both hands to check driver and passenger side tires for slight wobble. If wobbles, you have a bad ball joint. Otherwise inspect tie-rod end for wear.

you have bad wheel bearings or a bad spindle. i recommend repairing it as soon as possible.