That low tone noise you hear when a truck drives away

Jkust

Original poster
Member
Dec 4, 2011
946
Ok so as you guys know, I have basically two identical 360's. Identical in all ways drive train wise except for the G86 in the 9-7. So when I pull away slowly in the 9-7, like still in first gear, I hear that low tone that you hear when a big Silverado or something similar pulls away. Like the rear end noise from a really high rear end gear ratio. The Rainier on the other hand that has the same V8 and 3.73 doesn't have that same low torquey kind of noise. It's basically quiet. I've heard the noise a million times from other larger suv's and trucks but only one of mine makes it. Is that the rear end making that sound and why do two identical 360's sound different? Maybe it's the fans or something else but honestly I always assumed the noise was the rear ends.
 
Feb 24, 2012
133
What gear ratio is in the 9-7?

That noise is usually first gear in the transmission, not the rear end.

What if you put the Rainier in 1st and wind out the RPMs. Do you hear it then?
 

MDBT

Member
Jan 26, 2012
223
3.73 in the Saabs.

Could you describe the sound a bit more? Trying to determine if I know what you're talking about, and of course if I hear it in mine.
 

Jkust

Original poster
Member
Dec 4, 2011
946
deekster_caddy said:
What gear ratio is in the 9-7?

That noise is usually first gear in the transmission, not the rear end.

What if you put the Rainier in 1st and wind out the RPMs. Do you hear it then?

The 9-7 also has the 3.73. Winding the rainier out the noise is barely audible even with the windows down (both have the same sound insulation package as well).
 

Jkust

Original poster
Member
Dec 4, 2011
946
MDBT said:
3.73 in the Saabs.

Could you describe the sound a bit more? Trying to determine if I know what you're talking about, and of course if I hear it in mine.

Sorry was posting when you typed this. Its sort of a loud fan-like noise with a medium tone to it kind of unidirectional but don't think it's the fan. It gets louder as the rpms rise but you only hear it when you go slow and it is really noticable when I'm in my covered parking garage at work. Like I said when you pay attention to truck's in a parking lot you hear it all the time if you are close enough and I always attributed it to larger pickup trucks but was suprised when the 9-7 make it. Think of the sound you'd hear a military wheeled vehicle make while it's going slow through the mud. That is sort of the same sound.
 

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