Strange vibrations/shaking under acceleration???

I have a 97' Mitsubishi 3000 GT/SL - 5 speed...When I am under acceleration (above 60-70 mph) the car shakes. This happened all of the sudden-when on a road trip-I did not hit anything/was not in an accident. Sometimes it's a lot worse then others, and sometimes it doesn't happen at all. If I put the car in neutral the shaking stops... I have already replaced the mounts, I have new roaders & I balanced the tires. Do you think it could be the axels? Please help!

could be the mounts if u say it shakes alot when ur accelarating. So get that checked out as soon as possible cause u dont want ur engine falling out while ur driving lol. If it's not the mounts then it should be something fairly simple

You could be out of aligment. Potentially your tie rods are going. Possibly the bearings are going as well. Its also possible your tires are out of balance again. If one of the weights wasn't fastened well enough it could have fallen off.

You could be out of aligment. Potentially your tie rods are going. Possibly the bearings are going as well. Its also possible your tires are out of balance again. If one of the weights wasn't fastened well enough it could have fallen off.

How do I check the tie rods or bearings???

The mounts were already repalced - any other ideas??? How do I check the tire rods & bearings?

Sorry this might sound stupid. But you should check your rims, and make sure all the lug nuts are tightened.

Would the car shake all the time if a rim was bent?

One of the rims is cracking/tiny tiny crack - could that cause the problem??

Possibly, the thing with shaking is it usually gets more noticeable as the speed increases. My tire isn't balanced properly, and it vibrates and produces alot of noise between 60-80mph. Below or above that, it isn't as audible. Check everything Yogs mentioned, as they are the most common reasons.