Hello, my 1982 shakes after like 60mph. Starts minor, then gets more noticeable at higher speed. Haven't taken it past 75mph for this reason. Shakes with and without brakes, hitting brakes doesn't make it better or worse. No shaking till about 60mph. Just got this car, has had alignments before but cant tell you when last one was. I didn't do any suspension work on it. Cant tell you if the car drives straight if II let go of the steering wheel, since my steering box has play.

Thoughts on how i should diagnose this first? Alignment or wheel balancing? or anything else?

 

I would first check the wheel balancing and take it from there.

 

Sounds like a bad idler arm. But I would inspect everything in the front end.

 

As Roger said start out with wheel balancing, then move onto what 4-Vettes said. If none of that fixes the problem inspect all the U-Joints.

 

could be an alignment issue. if you feelk it in your steering wheel then its likely the culprit, either from a worn steering part or bad alignment. I had a castor issue that would show up in a slight turn at about 60 to 65 mph. Some folks called it tram lining. 89, 90 XJ Cherokee Jeeps would do the same thing, very famous for it. It was called a death wobble in those things.

I would start with the typical ball joint and tie rods test jacking the front end up and wiggling/ shaking the top and bottom of the wheels(ball joints) then grab the sides and do the same thing (tie rods). then move the steering wheel to see how much slop there is before the steering rack starts to move. get a helper and with the motor off have them turn the wheel back and forth about 10 and 2 of the steering rotation so its a qucik back and forth. any slop will easily been seen visually. from the pitman arm to the idler arm. if its all inthe steering box loosen the nut and screw the screw in a1/4 turn at a time to take up the slack but do not go so tight you get any resistance or binding. IF you are uncomfortable with this adjustment have a pro fix your box. Then start over with the steering box test to test the other components.

If it all is in good shape then your alignment or balance is out

 

Great advise from all.
i chased high speed vibration and shifter vibration until finally fixed.
it was many items but i strongly suggest
- high speed road forced balancing , i used discount tire..
see here post 21
https://www.corvetteforum.com/forums...ng-please.html
- inspect as mentioned driveline components..u joints etc..
- consider an alignment from a competent shop even a chain if right mechanic there..this should include basic suspension inspection.
see here post 46..also see diy methods others contributed.
https://www.corvetteforum.com/forums...uestion-3.html
- driveshaft balancing.
see post 19
https://www.corvetteforum.com/forums...ng-please.html

i suggest also taking pictures of your suspension components and posting. There may be obvious signs others can help with.
also post the manufacturing date of tires and or pics.
I had 2 tires that were out of round..

 

What's the date code of your tires, they are probably old

 

last 4 on DOT is 1316. so 2016, not that old, Plenty of tread on em

 

Thanks for this info. In a previous round of diagnosing steering, Ive isolated it to the steering box. I didn't do a steering box adjustment yet, because I was kinda ok with the slack that it has. But if this could be a potential cause of the shake, then I should properly adjust it. Ill do that today and report results

 

Will do, thanks for the posts. I read all of them, ill diagnose driveshaft after I'm done with the front end

 

check your front end first idler arm etc …. If all is good check ur tire date could be bad tires. Hope that helps

 

How's the engine regarding your intake fix? I assume you got the spark plug sorted?

The steering box lash adjustment is important and simple. Just be careful not to make it too tight - follow the directions. Should firm up the sloppy, wandering steering but probably unrelated to the shake.

All good advice on the shake. Start with the front end just as a general maintenance check - lots of consumable wear parts up front like ball joints and tie rod ends. Not hard to change them out when/if needed. Inspect your upper and lower A-arm bushings too. Cracking of the visible rubber is common but not a huge concern as long as the inside bushing is still held firmly. IF you end up changing upper and lower ball joints, this would be a good time to replace the a-arm bushings too if they're looking sketchy. ("As long as I'm here, might as well...")

 

Oh yea I did. Turns out with the spark plug think that the hole was so gunked up with oil that it was skipping threads. cleaning the threads sufficed. The car runs beautifully now, put at least 500 miles on it since the intake. Thanks for asking!

So fixed steering yesterday, feels great. The shaking has been reduced a good bit too, not perfect just yet tho. Next on diagnostics list is wheel balancing. I haven't diagnosed my ball joints yet, I think ill do that after the wheel balancing. In all likeliness my ball joints need some work.

 

Glad to hear it's running well. Job well done!

No better time to check the ball joints as when the car's off the ground for wheel balancing...