[GunMetalGrey]

My suspension and alignment shop says that the steering shaft is oblong/ eccentric and is making contact the long tube headers when the engine rocks back and forth on the engine mounts.

While I still don’t think this is the cause of the noise and vibration i’m experiencing at about a quarter turn to the right , does anyone know if the steering shaft is supposed to be anything but straight?

This car was in a crash on the race track last year at this time And if you parts were replaced on the front end, mostly body parts and radiators and intercoolers.

[Vtor_ZL1]

Isn't exposed section of steering shaft D-shaped? I'd go look.. but raining.



I woudl be more concerned if it was bowed - easy to check, jack up frotn end, have a buddy turn steering wheel left to right and see how much space from shaft to header changes.

[radz28]

Do you know if the shaft was removed or loosened when the LTs were installed? If they were, I could see where it might not have been reinstalled squarely and it causes the condition you're experiencing.

[GunMetalGrey]

Originally Posted by Vtor_ZL1

Isn't exposed section of steering shaft D-shaped? I'd go look.. but raining.



I woudl be more concerned if it was bowed - easy to check, jack up frotn end, have a buddy turn steering wheel left to right and see how much space from shaft to header changes.

It’s definitely bowed, I noticed that too when looking under the hood and having the steering wheel turned because it got closer to the headers

[GunMetalGrey]

Originally Posted by radz28

Do you know if the shaft was removed or loosened when the LTs were installed? If they were, I could see where it might not have been reinstalled squarely and it causes the condition you're experiencing.

It was but it only became a problem after the engine was moved around when the oil pump was replaced. Not sure if they touched the steering shaft then or not but I’ll ask the dealership.

[MartinLe]

Not supposed to be bent nor oblong - but still could be crazy

[GunMetalGrey]

Thanks for the info!

I guess obviously the engine would “vibrate” a lot at any RPM, and with that high frequency vibration perhaps it sounds like rotational noise because it’s so constant when in contact with the Stering shaft … also the harder the corner the more the engine would lean over…

My suspension in alignment shop verified that the headers are indeed contacting the steering shaft

[GunMetalGrey]

GM says there is a CV joint in the steering column shaft and that because it flexes it would get closer to the engine and then farther away again when rotated

[radz28]

Originally Posted by GunMetalGrey

GM says there is a CV joint in the steering column shaft and that because it flexes it would get closer to the engine and then farther away again when rotated

Yes. That's what I was getting to, in that if the shaft has been removed, squaring it to the joint will help keep it from moving out of it's centerline. I'm not saying that's the only possibility, but that it is one.

[GunMetalGrey]

Originally Posted by radz28

Yes. That's what I was getting to, in that if the shaft has been removed, squaring it to the joint will help keep it from moving out of it's centerline. I'm not saying that's the only possibility, but that it is one.

Thanks for clarifying

[GunMetalGrey]

So the long tube headers were making contact with the steering column, now that the engine has been shifted over slightly on the mounts, the noise is gone. I can’t believe how much it sounded like a rotating noise when it wasn’t

[Eric10905]

A late addition... and not a ZL1: I have encountered the same thing. I was concerned since, esp during hard cornering on the track, the headers were hitting steering shaft. I coudl feel it in the steering wheel. It had chipped my ceramic coating. I was worried that the factory motor mounts had given up. Performance shop I use did the same thing: had some one turning it will up. One of the sections is bent. I also don't fully understand it, but they are replacing it today, along with putting in a new (track) alignment.

[GunMetalGrey]

Are you going to have your headers dented so it doesn’t make contact anymore?

I’m not sure it’s worth it or not, but I’m still hearing and feeling some (albeit less) noise on the street so I’m just little concerned that when I go to the track it’s going to be substantially more. Still not sure it will cause any actual damage, but I also don’t want this noise and feeing to cover anything else up that I otherwise might feel or hear while tracking the car.

[Eric10905]

Originally Posted by GunMetalGrey

Are you going to have your headers dented so it doesn’t make contact anymore?

I’m not sure it’s worth it or not, but I’m still hearing and feeling some (albeit less) noise on the street so I’m just little concerned that when I go to the track it’s going to be substantially more. Still not sure it will cause any actual damage, but I also don’t want this noise and feeing to cover anything else up that I otherwise might feel or hear while tracking the car.

Not funny, my shop is only just now receiving the new part. sigh. Probably not going to (further) dent the headers at this time. I am thinking i might try it as is after they replace the section, and decide after the next track day. I hope it is worth it... i very seldom felt the hitting/rubbing on the street. But definitely felt it on the track. I found it distracting, and as you note, might be masking other steering feedback.

But might be Jan-Mar before another track day. I don't expect sympathy on that point from someone in Canada. lol ;-)