2008 Alpha Low Grade Hum and Vibration

[okcrewed]

Getting used to the Alpha after a long relationship with a fine 2006 Luxury H3 5-cyl. PPI by an out-of-state GM facility found no issues, and actually raved about the good condition of the truck. But I noticed a very low grade hum and vibration that the 5-cyl H3 didn't make, and since I didn't want any surprises off-road, I took it to a local GM service facility to have them check it out. They found one hub making a bit of noise, so I had them replace that hub to the tune of $1300+. And still no change in the low grade hum and vibration. Longer story made a bit shorter, I had a lengthy conversation with a local Chevy service manager and the upshot was that he didn't think he could help me: I need someone who is familiar with the Alpha to tell me whether that low grade hum and vibration are normal or not.

So...... Alpha owners, is that low grade hum and vibration just peculiar to the Alpha? Doesn't change with speed or rpm. Radio can easily drown out the hum. I'm about ready to accept it as "normal" and take off on an adventure!

 

[Happy Hummer]

Wow $1300! I just purchased two hubs to my door for a princely sum of $100 tops.
I made a special grease fitting several years ago for the h3 hubs. I get them sent to me from eccpp, the hubs, that is and grease them with 30 - 40 pumps while rotating counterclockwise then clockwise . When I see grease spew out of bearing seams I know it's golden.
I've found this is a good alternative to expensive manufacturers prices.
Yep, I've tried acdelco/ gm, timken, Moog, precision, etc.
They all die in s.e. Wisconsin chemical winter .

As far as vibration/noises I'll deffer to other members.

 

[okcrewed]

Wow $1300! I just purchased two hubs to my door for a princely sum of $100 tops.
I made a special grease fitting several years ago for the h3 hubs. I get them sent to me from eccpp, the hubs, that is and grease them with 30 - 40 pumps while rotating counterclockwise then clockwise . When I see grease spew out of bearing seams I know it's golden.
I've found this is a good alternative to expensive manufacturers prices.
Yep, I've tried acdelco/ gm, timken, Moog, precision, etc.
They all die in s.e. Wisconsin chemical winter .

As far as vibration/noises I'll deffer to other members.

Yeah, $1300 got a "WOW" out of me, too!

 

[alrock]

While I didn't own an Alpha, I spent enough time in one as a passenger and driver to say that I did not experience any low grade hum or vibration. All I can think of is a drivetrain part contacting body or frame, like a worn transmission mount or something like that. But that's only a guess, of course.

 

[HummerMan7]

Short answer: no, a constant low hum + vibration isn’t “just an Alpha thing.” If you feel/hear it sitting still, it’s likely engine/exhaust/AC/fan or a mount. Only when moving - more likely tires/wheels/driveline (bearings, u-joints/CVs, diff, transfer case), or something touching the body

 

[okcrewed]

While I didn't own an Alpha, I spent enough time in one as a passenger and driver to say that I did not experience any low grade hum or vibration. All I can think of is a drivetrain part contacting body or frame, like a worn transmission mount or something like that. But that's only a guess, of course.

Well, it's a better guess than anything I've come up with! THX!

 

[okcrewed]

Short answer: no, a constant low hum + vibration isn’t “just an Alpha thing.” If you feel/hear it sitting still, it’s likely engine/exhaust/AC/fan or a mount. Only when moving - more likely tires/wheels/driveline (bearings, u-joints/CVs, diff, transfer case), or something touching the body

My thinking, too. But two GM service centers found nothing. Hum and vibration don't change much, if at all, with speed or rpms.

 

[650Hawk]

No noticeable hum/vibration on my Alpha, but I can't compare it to a I-5 since I've never driven one.

 

[Jeepwalker]

Curious what your hub greasing device looks like ...mind sharing?

 

[lfootmatt]

No known hum/vib in our 08 Alpha.

Front drive shafts are pretty notorious. Easy to test, pull it, put it in 4 high lock and drive it.

Later!

Matt

 

[rascole]

Sounds like you bought a Hummer. But in all serious, a hum that doesn't change with speed or RPM, could be electrical related. Pull the fuse to the Onstar, unplug the alternator while at idle, pull the fuse to the radio and amp if it has the Monsoon stereo.