I get a bad vibration on the high way at around 65-70 mph, it causes the dash board to shake, seems to be coming from the front end, wondering how anyone has solved this problem because ive heard of it many times, but cant come up with any info on a search

 

My firebird use to do it at 80 mph and i did a front end rebuild and sovled the problem. but my tie rods were really bad. you might want to check your tie rods.
Martin

 

also, the vibrations seem to stop once i hit 80mph or higher. it only vibrates between 65-75, really weird

 

worn
transmission mounts
and engine mounts

cause the exact same problem too.
but ofcourse replacing ur front end will probably help stabilize ur car too.

 

Looseness somewhere between the steering wheel and either or both tires is usually what lets this happen. But I'd also check the simpler things, like tire pressures (right vs left), alignment (ditto - you'd be looking for the "cross camber" and "cross caster" numbers on an alignment printout to be zero or very small), and bad wheel balance or cupping.

It's pretty much normal for vibrations to peak within some range and die out either above or below that range. That's the nature of 'resonance'. The width of said range depends on other characteristics of the 'system' that's doing the vibrating, but it is entirely possible for a plot of vibration magnitude vs speed to be a rather sharply defined peak that drops off to almost nil very quickly on both sides.


Norm

 

Tire wear?

JamesC

 

Go get your tires balanced. Make sure they watch the tire as it spins on the balancer, as there is a good chance you have an out of round tire or rim if it's shaking the dashboard.

If tire wear was causing it there would be noticable feathering or cupping on the tread, and the vibration wouldn't go away at higher speeds.

Alignments don't cause vibrations. They cause tire wear and drivablility concerns. Toe will give you a crooked wheel and inner or outer edge wear on the tires. Camber will give you more pronounced tire wear, cross camber will cause a pull. Caster affects high speed stability, cross caster will cause a pull.

The same goes for worn front end parts. It's rare that they will cause a vibration, normally only tire wear and a loose feeling in the steering wheel. Normally worn out balljoints or tie rods will only cause a vibration over bumps. (Ever heard of "death wobble" in lifted Jeeps & trucks?)

Sorry for the rant, I did nothing but front end work and alignments for 3 years, so people asking for alignments to fix a vibration is one of my pet peeves. Long story short, get your tires balanced.