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Discussion Starter #1
hi there,
the SRX book says fulltime AWD.
it says:
engine power is sent to all 4 wheels all the time.this is like 4x4 but it's fully automatic.

my GM service manager says it's FWD till it slips or skids,loses traction etc then the AWD system comes in,so quick it;s not noticable.......so which is it.
Permanent 4 wheel drive or FWD till it needs to be AWD ?
thanks
Pinky
 

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More info from GM Tech...not sure how/if this applies to 2007 though...

"The all-wheel-drive system available on the 2010-2011 SRX and LaCrosse features a Power Take-off Unit (PTU) in the front final-drive that transmits engine torque through a prop-shaft to the Rear Drive Module (RDM).

The RDM includes a Torque Transfer Device (TTD), or differential clutch, and an electronic Limited Slip Differential (eLSD). Both are wet, multi-plate clutch units. The TTD is activated as soon as the vehicle is placed in gear. RDM clutches are applied and ready to transfer torque before acceleration begins. Wheel slip or driveline rotation does not need to be detected before the rear drive is activated, which provides maximum traction immediately.

During driving, torque delivery between the axles is varied by a valve in the TTD, which increases or reduces the hydraulic pressure on the wet clutch plates to progressively engage or disengage rear drive. The degree of slip determines the amount of torque transmitted. The eLSD, located alongside the RDM, operates on the same principle as the larger TTD. The electronic control unit functions in concert with the engine, transmission and ABS/ESC control modules."
 

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The Equinox and the Terrain also got the Haldex AWD system.

From motortrend : The optional all-wheel-drive system is Haldex based and incorporates an American Axle-sourced limited-slip rear differential featuring an electronically controlled clutch pack to distribute torque left or right.
 

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I'm pretty sure that on the Equinox/Terrain it's a Haldex brain and only a different brand for the rear differential that prevent the listing of them on the Haldex website and that explain also the little difference in the price of the Equinox/Terrain and the SRX. And from what i've read at different places,it can also be that the Equinox/Terrain use the AWD from Haldex... and the SRX use the XWD more evolved system also from Haldex...
 

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Haldex is actually owned by BorgWarner now.
 

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Your service manager is mistaken.

In 2007 the SRX was built on the RWD/AWD Sigma platform(CTS & STS) not the FWD/AWD Theta('Nox & Terrain).

The AWD GM used on those vehicles is a symetrical system developed while GM still had partial ownership of Subaru and I don't believe it has any affiliation with Haldex.
 

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Discussion Starter #11
GMCdriver said:
Your service manager is mistaken.

In 2007 the SRX was built on the RWD/AWD Sigma platform(CTS & STS) not the FWD/AWD Theta('Nox & Terrain).

The AWD GM used on those vehicles is a symetrical system developed while GM still had partial ownership of Subaru and I don't believe it has any affiliation with Haldex.
Ok so now I'm a little confused........but learning lots.Anyone got written proof,an e-mail link,I wonder what the original 2007 SRX AWD brochure said on the subject - if anything ??
any more technical info on the RWD to AWD system would be welcome too.
Thanks
Pinky
 

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pinky said:
Ok so now I'm a little confused........but learning lots.Anyone got written proof,an e-mail link,I wonder what the original 2007 SRX AWD brochure said on the subject - if anything ??
any more technical info on the RWD to AWD system would be welcome too.
Thanks
Pinky
Pop your hood and it should be pretty obvious, is your engine mounted transversly(FWD/AWD platform style) or longitudinally(like RWD/AWD platforms). Yours is longitudinally.
 

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GMCdriver said:
Pop your hood and it should be pretty obvious, is your engine mounted transversly(FWD/AWD platform style) or longitudinally(like RWD/AWD platforms). Yours is longitudinally.
Interesting "rule of thumb". Never thought about it that way. THX
 
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