Mitsubishi: car vibrations, car glove compartment, cv axles

Question
Well, its a 2000 galant 4 cyl.  well, i can hear the vibrations from the busted motor mounts inside the car  ( glove compartment and things like that ) when its in idle or in reverse.  is the harmonic balancer expenisive to fix?  because i have good tires, new struts, bearings, alignment and the tires are balanced.  it only vibrates at about 70 mph
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Followup To

Question -
Can busted motor mounts cause my car to vibrate at highspeeds, and is it bad on the car not to get them fixed ?

Answer -
Good Morning OKeith,

Motor mounts and transmission mounts keep these components in place number one, but also insulate vibration from these and other components from reaching the car's passenger compartment. Not knowing the year and model, I will have to be general in this answer. If you are noticing vibration at only higher speeds, I would look at tire balance or harmonic balancer. If this is rear wheel drive you might also check your u-joints. If it where a mount problem you would notice the vibration even at idle. The harmonic balancer is the pully located at the front of the engine and is connect to the engine's crank shaft. There is a rubber insulator inside there and sometimes the harmonic balancer will "slip" inside and throw it out of balance. Hope this helps, keep me posted!

Answer
Since you can hear and feel vibration of the mounts then start with that first. Also because the viblation is only at 70 I really suspect an incorrectly balanced tire(s) might be hiding in there too. The harmonic balancer should be under $150.00 if you find an honest shop. My recommendation would to first, replace the broken and worn mounts, engine and transmission because they are an obvious problem and need attention reguardless. While they are in there have them inspect your CV axles for wear or damage. A torn boot will leak out all of the gear lube and also collect dust and sand which in turn will wipe out the CV joint and will cause uber-vibration. If that doesn't take care of it then have a reliable tire center re-balance your treads. Lastly, if you still have this issue look for a shop that specializes in motor repair to have them inspect the crank pully or harmonic balancer. Pep Boy's would be a good place to start. They should be able to handle all of these items and will inspect your car for FREE! Hope we find it in all this! Please keep me posted! I want to stay on top of this one. Thank you!

Follow Up: Hi O'Keith, did the mounts fix this? Or was it the balancer? or was it something else? Hope I was a help... Thanks again, Dave (Dinger)