Replaced air w springs, now vibration at 65+, alignment?

[SuitedSpikes]

Title pretty much says it all.

I replaced the air suspension bags with springs from strutmasters. Super easy job for the do it yourselfer.

Now when I go 65 mph there's a definite vibration. Tried it in a different gear to make sure it's not the engine and the vibration is still there.

Is alignment a common issue when changing from air bags to springs?

Also of note, I cleaned the mass air flow sensor with CRC MAF cleaner and put Seafoam in the tank at 1 oz / gal. I seriously doubt if either of these could be the cause. Nonetheless, they were other changes made prior to the vibration starting. Idle is smoother now ... ;-)

So the question remains ... air bags to springs alignment issues.

[iwillnc]

I highly doubt what I'm about to say is remotely close to the problem but...

The rear stabilizer bar on the air suspension is 32mm on the shocks it's 30mm, at least for the 09's on the HUMMER site.


Again I highly doubt this is the problem since tons of other members have replaced this and it worked for them. But I tried to help lol
And honestly I'm not even sure what the bar does...

just my .02

[timgco]

Things to check:
* Make sure your spring seats are in properly and new coils are seated entirely.
* Did your tires get switched maybe? It could be that they were swapped and uneven tire wear could casue the vibration when switching sides? not sure, but popped into my head.


That's all I can think of. Pleanty of people have swapped without issue, so if it is related to your swap, I bet it's one of the things mentioned above.