vibrations after new wheel/tire install

[crm318]

yesterday, i took the brand new (1000 miles on them) 275-60-15s and 15x8 wheels and tires off of my perfectly riding 78 sport van and put them on my 72 cheyenne. it rides fine in town, but when i get on the highway, it will have a slight vibration (i can see things bouncing in the cab). what could cause this? i thought it would be a direct swap. how can this be when it rode perfectly on my van?

[Longhorn Man]

Is there a chance you didn't tighten the lugnits?
Or maybe a chance that the lug nuts are closed on the end and couldn't spin all the way on?

[crm318]

ill give it a closer look and get back to you.

[FlatBrokeRacing]

Where spicificaly is the vibration at.?

[crm318]

im not sure where is occurs. today, i took the center cap off and saw that the center hub of the rotor had a 16th of an inch of gap all around it between the wheel. the rally wheel fit perfectly flush. i have switched them out and no more vibration. these wheels were ordered for a 78 chevy truck. how is it not compatable. it was also the same on the van too.

[orange72c10]

I would wonder if your tires are wearing differently than they did on your van. Maybe your alignment is just a little bit different. Another questions for you is are the tires rotating in the same direction that they were before? Sometimes that makes a difference.

[crm318]

they were put on the same way.

[70rs/ss]

It could be a slight tire weight difference and your drivetrain, because it sounds speed dependant, maybe the tires/wheels are causing another issue to be more prevelant?

[Longhorn Man]

gotta figure why the wheel isn't going on all the way.

[Fatherflash]

My .02

I would recommend you look at your suspension mounts, and also consider your shock(s) and or springs. It may be that your tire is slightly out of balance/round and was compensated on your other car.

You could have a worn shock, loose mount somewhere, which is all worsened or magnified by a out of round or out of balance (slightly) tire.

If you have something that is slightly out of balance or round such as a tire, spin it at high speed, you can create a pretty sizeable vibration.

Is this happening with only one tire, two tires, or all of them?



I am by no means a suspension guru, just done a lot of work with vibration.

[Longhorn Man]

He already found the problem.

Originally Posted by crm318

today, i took the center cap off and saw that the center hub of the rotor had a 16th of an inch of gap all around it between the wheel. the rally wheel fit perfectly flush. i have switched them out and no more vibration...

[crm318]

i would think that the lugs would keep the wheel centered, but the center should also take up a good share of the load. its a shame.......and annoying to swap them back.