So after getting new tires recently, and balanced twice, I realize I have to check some other things like sway bar bushings, u-bolts, driveshaft, etc.... In anyone's opnion, Is the typical high speed shaking a serious thing to consider for a 4 hour road trip?

 

vibrations are a bad thing and they can hurt the car, more or less, depending on what is causing them. is it actually a vibration? or is the engine running rough/missing? is you steering linkage work out and loose?

 

Yea 4 hours will do a good amount of damage. Ive had a vibration in my minivan for a long time, it was impossible to trace where it was coming from. Definately front end. I machined the rotors true, got new pads, installed new ball joints, inner and outer tie rod ends, and installed a new rack and pinion to eliminate play in the wheel. 3 months later the ball joint and one tie rod end was gone out, and the vibration was back. Wheel balancing didnt help.

Turns out the wheel isnt round, it had the slightest shimmy that i couldnt detect on the balancer, and when the temperature changed, the rim would be closer to the road because of less tire pressure. So it just did damage again.

You wont kill yourself over 4 hours, i drove the van around plenty, just try not to drive on the vibration, with 60mph its gonna be tough so id get it looked at. Im just saying it WILL do damage, and will cost you more $ the longer you put it off. Good luck!

 

You and your car will not be happy after 4 hours.

It's likely your driveshaft. Get it checked.

 

doesn't the stock '91 rs come with 15" rims? I ask because upon buying my car, I realized the previous owner put on 16" IROC rims with tire sizes 225/60/16 ..... Could this cause vibration issues?

 

there are a ton of things to vibrate on third gens. have everything checked out closely, i have had two different problems myself lately, the struts mount were worn, that was one, and the pinion bearing went bad and i didn't find that one for a while. both of those were pretty hard to find, just an idea for ya