Lowered my 2008 Avalanche 4WD

My 1st mods on my new to me Avalanche.

(1)I lowered my 2008 Avalanche LTZ 4WD using the McGaughys 2" front spindle/3" rear spring kit.  Pretty quick install as I spent more time gathering tools & cleaning up afterwards than the actual install.

* The pictures in the instructions were so dark that they were useless.
* Kit has you bend the rear air shock leveling rods. 1st 1 bent no problem, 2nd snapped in 2 as soon as I started to bend it so I cut to lenght then welded it.
* Kit comes with self tapping (more like self breaking!) screw to install the ABS sensor bracket to the untapped spindle so I tapped them myself.

(2)Replaced stock wheels/tires for 20x9 rims that I had on my last rig & new General 295/50/20 UHP tires.

(3)Installed Diablo Predator performance tune with some minor tweeks.

End result my Avalanche carves corners with very little body roll & the newfound throttle response is just short of amazing! Gotta love the firm shifts as well!  I didn't want to drop it into the weeds so end results are what I was looking for. The new tires lifted it 1/4". Right after install measured drop from all stock was 1.5"F 2.5"R.  It should settle down another 1/4" or so in time.

looks good, thanks for taking the time to share all the details! Always wanted to lower mine.

So did you do your own tweaking to the tune or did you have someone else  do it?

LornesAV said:

So did you do your own tweaking to the tune or did you have someone else  do it?

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I tweaked it myself. I may go with a custom tune but I'll probably wait until I drop in the 630hp 7.0L.  I'm going to try to leave this motor alone but it's begging for a real cam & lifters.

Hope you don't take offense but I gotta ask why you'd lower a 4wd? Why not go w/ a 2wd?  Only reason I can think of is if you are a boat owner maybe?

I have tweaked mine a bit with a 2 mpg improvement but only 1.5 tanks. Only time will tell. I just changed the injector slope a little. Waiting till I hit a head wind that's the real test for mpg anyway. What other adjustments did you make?

I love the drop, it looks great!

I really want to know how your ride was affected.

I've looked at both kits but am gonna go BellTech. I have no idea of the quality of the McGaughy casting and springs...
but if they can't afford 2 cents for an actual install sheet instead of a bad photocopy,
and make you bend the rear air ride rods instead of a 20 cent threaded rod,
and they can't even tap the casting for an actual bolt...
What else have they cheaped out on?

Sorry Mr Monte, I'm not trying to put down your drop, cause it LOOKS GREAT.  
Just want others to know why drop kits vary so much in pricing.

looks good 

DouglasOak said:

I love the drop, it looks great!

I really want to know how your ride was affected.

I've looked at both kits but am gonna go BellTech. I have no idea of the quality of the McGaughy casting and springs...
but if they can't afford 2 cents for an actual install sheet instead of a bad photocopy,
and make you bend the rear air ride rods instead of a 20 cent threaded rod,
and they can't even tap the casting for an actual bolt...
What else have they cheaped out on?

Sorry Mr Monte, I'm not trying to put down your drop, cause it LOOKS GREAT.  
Just want others to know why drop kits vary so much in pricing.

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I lowered mine for better handling & looks. I love the way my Avalanche handles now.

The McGaughy casting and springs seamed to be high quality but I ended up taping the casting that they should of done & having to bend the rear air ride rods is a cheesy way to go. I ended up cutting/welding mine.

Sorry for the newb question. But where is the air ride? I have a 2012LT. But air that I'm. Aware of. My uncles ext has air ride. Did your Av come with air suspension? 

renderw said:

Sorry for the newb question. But where is the air ride? I have a 2012LT. But air that I'm. Aware of. My uncles ext has air ride. Did your Av come with air suspension? 

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I think air ride/leveling suspension is stock in second generation LTZ  AVs. In the first generation there was a z66 option in top level AVs that had self leveling rear shocks to help with soft ride and towing.

I think along the lines of 1Fastrider though about putting a lowering kit on a 4wd AV. There is so much plastic down low I would worry about damaging it in snow, speed bumps or other situations. I also think it's like trying to combine two things that normally don't go together. Like making a racing tractor.
Just my .02 but if i wanted a better handling/performance AV I would save weight and power loss by starting with 2WD and improving suspension and adding a large motor with probably a supercharger. I would realize it's not a sports car though since an AV is very heavy and has the aerodynamics of a brick.
All that being said I think every owner should customize their AV any way they like since they are the one that is paying for it and driving it.

Thanks Vaeagleav for clearing up the air lift, I managed to get a service manual and I see know how it works.

I like the idea of lowering, when the salesman asked me what I was looking for I said "A four door el camino" of course no one sells that, but if you lower an Av you get very close! my vehicles before this were a Subaru forester and a Mitsubishi outlander both AWD and I didn't want to give that up! you don't need the AWD/4X4 for everyday driving very often but on bad snow days it's really nice to have and raised or lowered 4X4 will still give added traction to get you through.

Nice Job Monte!

JVZL1 said:

I like the look I bet the handling is quite a step from stock.
Have you looked into upgrading the sway bar link ends to Polly or a Hotchkis package.

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I do plan on upgrading the swaybar end links to poly.

Vaeagleav said:

There is so much plastic down low I would worry about damaging it in snow, speed bumps or other situations. I also think it's like trying to combine two things that normally don't go together. Like making a racing tractor.
Just my .02 but if i wanted a better handling/performance AV I would save weight and power loss by starting with 2WD and improving suspension and adding a large motor with probably a supercharger. I would realize it's not a sports car though since an AV is very heavy and has the aerodynamics of a brick.

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I used to have a 1999 4WD Suburban that I bought new & put over 250,000 miles on it. Maybe 2 miles was offroad & 40,000 on snow/ice so the 4WD was a need for me. I ended up upgrading to 4.11 gears & a 500hp 383 stroker so I have a history of driving a fast aerodynamic brick. I sold it last Jan & bought a 2007 AWD Escalade (Tahoe size) with 6.2L/6 speed.  While not as fast as my Suburban the Escalade sat lower & handled so much better but was pretty useless for hauling none clean stuff inside.  The Avalanche is a good compromise for me.

With 2"/3" lowering kit the Avalanche still has good ground clearance so speed bumps are not a problem. The lower center of gravity really improves the handling & makes the Avalanche way more stable at higher speeds. I've had mine up to 120mph a few times & the ride is so smooth.  I was out playing in the snow the last 2 days so the 4WD was a real asset.  My future plans include a HD rebuild of the tranny & installing a 600+hp 7.0L motor. That should make for a pretty quick brick.