GMT-800 Suburban lift options?

[Martinjmpr]

DONE!

Well I decided to farm out the keys to a shop and I think that was smart: They're done. New keys on, and a noticeable lift.
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Measurements are now as follows:

LF: 37.5
LR: 37.5
RR: 38.25
RF: 37
Hitch Bottom: 14 7/8
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So a full 2" all around from the lift, pretty much what I wanted and more than enough to run 33's. Whether I'll have excess CV wear or not remains to be seen.
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Photos should be coming soon, having some issues with photobucket.

 

[rayra]

Any idea what the installer's magic technique was?

 

[Pntyrmvr]

BFH


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[chilliwak]

Looks like a big:Wow1: improvement Martin. Let me know how you like the Bilsteins. Cheers, Chilli...

 

[LostChord]

I have a 2012 Yukon xl Denali and I put 33" tires on mine, I used a kit from http://www.ccmoffroad.com/chevy-gmc/...

I used 2.5" in the front and 2" in the rear.. works fine and looks great...

FYI, their leveling kit standard comes with only 1" in the rear, but it always looked like it sagged... so I switched to 2" in the rear and now it looks great...

Would love to see pictures!

 

[Martinjmpr]

Any idea what the installer's magic technique was?

I think they said an air hammer and lots of PB blaster. They charged me for 1.5 hrs of shop time, which I thought was a little high (I would have thought 1 hour would be plenty) but seeing as how it was something I couldn't do myself I'm not going to quibble over a half hour of shop time.

 

[Jelorian]

I think they said an air hammer and lots of PB blaster. They charged me for 1.5 hrs of shop time, which I thought was a little high (I would have thought 1 hour would be plenty) but seeing as how it was something I couldn't do myself I'm not going to quibble over a half hour of shop time.

Glad you were finally able to get them out. Any pics of the new stance?

 

[Martinjmpr]

Glad you were finally able to get them out. Any pics of the new stance?

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Tried to upload them to Photobucket but it's been giving me fits. Here is the before:
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And after:
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[Martinjmpr]

Now the next big question is tire size: I'm looking at going with BFG AT KOs and they have both 285/75/16 (32.8") as well as 295/75/16 (33.5".) The price difference is negligible between the two ($31 on a set of 4) so I guess my question would be, is the additional diameter of the 295 likely to cause problems while driving? I have the 3.73 rear end.
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My inclination at this point is to "play it safe" and just go with the more common 285s.

 

[rayra]

Thx for the removal method info, was just wondering if there was some new way under the sun.


285/75/16 (32.8") as well as 295/75/16 (33.5".)

well it's only a 2% increase in diameter / circumference / mechanical advantage / moment arm, between the two.
And starting with a factory size of 265/70/16, 30.6", it's a 7.2% and 9.5% increase, respectively. shrug, once you go up that step in size class, I don't think it much matters. Either one is going to add some bog.
With your towing, I'd suggest forestalling the taller tires until you can re-gear appropriately. Vehicle alone, I'd say go for it, not going to matter much. Plenty of folks upsizing without any dire effects. But the towing is something to consider.

 

[Martinjmpr]

T-bar bolts sticking down?

Hey, is this something to be concerned about? Look how far the T-bar adjusting bolts stick down:
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I think they're hanging a good 1/2" - 3/4" below the cross member. Not like I plan on doing any hardcore "off roading" in this, but does anyone else worry about these things hanging down like that? If I'd realized how far they'd hang I'd have swapped them out for shorter ones (if such are available - not sure if they are.)
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I don't want to crank them up any higher, my front end is as high as I'd like it and I'm afraid that any higher and I'd start having real problems with the CV joints.

 

[rayra]

yeah, only a concern if you are high centering / grinding on something. And your transfer case and rear driveshaft yoke / rear end of your driveshaft will be hazarded by then anyway.

Those look like they are hardly turned in at all. Shouldn't be hard to find or make shorter bolts. IIRC these have a conical tip, fitting in that indent in the torsion keys. The easiest fabrication might be to scavenge a replacement set from a scrapyard and cut them down and shape their tip on a grinding wheel. Put a thread die on them before they are cut and ground, to make cleaning up the threads easier.

Make swapping them easy by chalking an alignment mark on the keys before pulling the bolts. Then you can just turn in the replacements to re-align the mark. No getting up and down to re-measure.


I'm still deciding who to give my money to for a new taller set of rear spacers, then I'm re-doing my lift all over again. And adding my shock boots. And tie rod sleeves. And maybe ball joints while I'm at it, before my re-alignment. Finding some nice delrin spacers available. irks me to pay $45 for $5 worth of plastic. If I had a lathe I'd make my own.

 

[justcuz]

Just,

I debated about whether to ask/update here or in the other thread, but this seemed like the better place.

I did the front keys on my 2002 Avalanche, and added a rear 1" spacer. Have the lift I want, but now I do need to stiffen the back, for loads. I am trying to do the "better" springs first, then will decide whether I need to add air. Not trying to get more lift, just more load capacity for my small motorcycle in the rear hitch, with the rest of my Av bearing full camping gear.

Per this thread, and the other one, you seem to have confirmed that the H2 springs in my Avalanche should stiffen the rear for load?

In doing a ton of research this morning, and trying to find these springs, here is what I found. First, the Moog 81069, by reviews on Amazon, appears to be a factory replacement. Reports there indicate they are for the Z71 package, which I have, and in my case might only restore the factory rate (Z71). For folks without the Z71 package, the reports are more lift, but no one discussed load.

OK, I could not find the part numbers you have above on GM Direct. Searching by 2003 H2, I found #25956182 and 183. More searching and another GM website indicates 15179496 may be replaced by this 25956182 & 183. So I am a little in the dark on this, and am contemplating using just the H2 search and going with what may be new part numbers. If you have any thoughts, I am all ears.

Otherwise, I may just cross my fingers and hope for the best. I would imagine if I decide to add air bags, I am probably going to have measure inner diameters of what ever I end up with, and consult the mfg. for the correct bags.

Thanks for all your help in this, and hopefully this might help others trying to do this.

Craig

Sorry for the delay in responding, If you plan on hauling a fair amount of weight I would go with the H2 rear springs. They are probably not taller than the Z71 springs, but are progressively wound so they don't compress as much when loaded. They look just like old Moog Cargo Coils we used to put in our station wagons.

 

[Martinjmpr]

I'll get some pictures posted

As a note to OP, I went with 285/70/17 and I have a 2.5" lift in front and 2" in the rear... and with a small amount of trimming they fit... I would go with 285. Because

1. They fit
2. Way more options for 285 tires if needed.
3. 285 fits in the stock spare location without sticking too far down...
4. 285 fills wheel wells nicely and looks good

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Yeah I'm thinking 285s would probably be the better way to go. I'm going to keep my current spare tire at least for now - it literally has zero miles on it (It still has the rubber "hairs" that tires have when new.) Given that the horrible "Secondary latch" was completely seized, I can understand why the spare was never used - it would have been impossible to get down.

 

[Bear in NM]

Sorry for the delay in responding, If you plan on hauling a fair amount of weight I would go with the H2 rear springs. They are probably not taller than the Z71 springs, but are progressively wound so they don't compress as much when loaded. They look just like old Moog Cargo Coils we used to put in our station wagons.

Justcuz,

Thanks for taking a moment to reply. I definitely want to stiffen my rear. I do have the 1" aluminum spacers in there now with the stock springs, so I do have that as an option. I am going to do the H2 springs in a few weeks, I hope. I have a hunting trip coming up that will let me decide for sure. Running up to ranch last weekend (a bit of 4 wheeling) unloaded, I was trying to really focus on the "ride" so to speak. My Av does recover from dips correctly, just a single bounce, but overall with the front lift keys and spacers in the rear, the overall ride seems a little soft. Maybe it's just 24 years in the seat of a really stiff Jeep YJ, or maybe just stock Chevy springs with 134K on them. Either way, I want as little more truck, and little less Suburban feel.

For those of you stuffing the 285's, are any of you doing anything with the speedo calibration? I had a dog of time with my Jeep and taller tires, with getting the correct speedo gearing. Would that be something the dealership could program, or perhaps a tuner deal? I am a few years out from needing to replace my 265-70-17's, but having the factory 4.10's makes me think that it could be an option.

Craig