Hey Vortec Guys! / Sierra pickup / Suburban / Yukon etc - Finally has Index!

[Bear in NM]

Ray,

Thanks for the detailed information on your lift. I will be doing the same to my '02 Avalanche, and my install should be identical to yours. I am just trying to decide whether I want to do this myself, or have the shop do it. Done much of this kind of work on my replaced Jeep, but my shoulder is still a bit tweaked from the Jeep accident, so debating about the "hardness" level if I find something like a stuck in the key torsion bar, or something. And I would have to do this in my gravel driveway, with drives out to find pavement, for measuring.

I do have a question. I had already decided I would rent/borrow a spring compressor for the rear. Did you just decide to not use one, or is there a reason one may not work?

And great idea about switching the rear springs. I have measured a difference in my fender well heights in my rear, when fiddling with my front adjustment. I think the PO of my Av may have actually lowered the front at some point, as my adjustment screws were well out.

Thanks,

Craig

 

[rayra]

well I'd read that the springs would just fall loose if I lowered the axle far enough, sans tires (eta and that was true). And the last time I used a coil spring compressor I almost lost my left hand.

It was also a very hot July, 15yrs ago. I was changing the coil springs in the front of a '73 Formula 400 Firebird I was restoring. Had the car on jackstands, rebuilding the suspension, new bushings etc. Compressed a new spring, went to put it in; the old Pontiacs had a very deep 'bucket' at the top and I could not get enough clearance to tuck the spring in, even with the lower control arm touching the ground. The PROPER thing to do was back off, re-set the vehicle higher in the air and go again. In my heat-addled frustrated condition I made some very bad decisions. I cranked on a bunch more turns on the coil compressor. My master plan was 1) shove the spring in, 2) pick up the lower arm and hold it up, 3) roll the floor jack into place. Seemed perfectly reasonable to me at the time. I got to 2-1/2 when BANG, the compressor failed and the whole thing went off like a giant mousetrap, crushing / pinning my hand to the ground.

I screamed for help so loud a bunch of teens having a noisy pool party 3 houses down heard me. My other neighbors heard me inside their house. Another neighbor jogging the neighborhood with his kid in a jogging stroller got there first. By the time he had, I'd already done the adrenaline / hysterical strength thing and yanked up on the lower with my good hand (so hard I wrenched my elbow) and got my mangled left hand free. I was sitting in the driveway holding it together when they all ran up.

I was pressing up hard with the heel of that hand when it happened. Best I can figure, the violent motion instantly bent my wrist and the edge of the lower control arm cut into and raked down my palm, instead of just chopping thru my hand. Turned my palm into a pita pocket. If I'd been holding at the base of my fingers, it would have chopped them off. If at the wrist, I'd likely lost the hand. As it was they just had to thoroughly debride the wound and do a bunch of stitches. Turns out your motor nerves are on the back of your hand and your touch nerves are on the inside. I lost most of the feeling in my left middle and ring fingers. A lot of scar tissue that tugs and aches to this day. And my whole hand crunches like popping your knuckles, when I clench it. And I've got a terrific scar that exactly matches the outline of the end of the lower control arm.

And that's why I chose not to use a coil spring compressor. Mine is a grim regretful laugh.

/sorry for the long gory story, but I sort of have to vomit it all out once I start, or the nightmares start again. The visual image of that lower penetrating my hand is burned into my brain.

 

[Martinjmpr]

What size lift spacers did you go with for the rear? I'm on the brink of ordering my setup and am actually thinking of not ordering spacers at all - thinking that brand new Z71 springs should give me sufficient lift compared to my worn out LT springs.
.
Thoughts on this?
.
Keep in mind my only goal is (a) better ride without the horrible harmonic sound I get on rough roads and (b) the ability to stick 32.8" tires (285/75/16) underneath. A slight rake would be nice since I pull a trailer - a degree or two of rake would level the truck when the trailer was attached.

 

[rayra]

As for stuck keys, they're such a brutally simple mechanism that they're easy to take apart. If you have some corrosion at the bar / key interface just give the key end a spritz of penetrating oil the day before. The front end is steel torsion bar in the aluminum lower arm, it should come free readily. Or just give the key end of the torsion bar a rap with a hammer. Should come free easily. Too easily in our dry desert southwest. Beware Falling Keys. Heavy chunk of steel and it will fall right out once the torsion bar is slid forward enough.

 

[Martinjmpr]

Rayra: Am I right that you got this kit?
.
http://www.roughcountry.com/gm-suspension-lift-kit-270n2.html
.
Curious about the shocks. When I "priced out" a kit where I purchased each component separately, the cost of shocks alone (Bilstein 5100's front and rear) was more than this entire kit.
.
For those who have experience with the Rough Country shocks, are they decent? I don't mind spending the extra $$ for better shocks if it gives me a better ride and longer life.

 

[rayra]

What size lift spacers did you go with for the rear? I'm on the brink of ordering my setup and am actually thinking of not ordering spacers at all - thinking that brand new Z71 springs should give me sufficient lift compared to my worn out LT springs.
.
Thoughts on this?
.
Keep in mind my only goal is (a) better ride without the horrible harmonic sound I get on rough roads and (b) the ability to stick 32.8" tires (285/75/16) underneath. A slight rake would be nice since I pull a trailer - a degree or two of rake would level the truck when the trailer was attached.

I think you're probably right in that surmise. The Rough Country 270 kit came with only 3/4" high spacers. Not much gain for the effort. And the shape or the rear wheel well opening is almost vertical at the bottom corners, so if the radius of your new tires will fit now they won't fit much differently after such a small height change. But it is a prime time to put such a thing in, since you are changing the springs anyway.

My measurements at the top lip (edge of the opening, not the top-top of the trim piece) of the wheel well trim centered over the hubs

Driver Passenger
Front 37-3/4" 37-3/4"
Rear 37-7/8" 38-1/4"

That's with a full tank. And I'm pretty sure that the front and rear wheel well openings are not on the same height on the body. I'm going to drive it a bit and then use my factory nerf bar / step as a reference benchmark for 'level' on the vehicle.

And like bear, I've got a disparity in the rear, I probably ought to have swapped the springs side for side while things were apart anyway. There doesn't seem to be any difference between them otherwise.

For my part, the whole kit was cheaper than a stock set of Z71 shocks, which I needed anyway. So I put the whole thing in. And I'd previously had a weird rebound over bumps, the rear left seemed to be bouncing harder and I wanted to inspect springs. But I now think that's just the Suburban's geometry. With a full tank and my fat butt in the driver seat, it's a lot of weight on the driver side and rear, which is likely why it rides a little weird on bigger bumps.

 

[rayra]

Rayra: Am I right that you got this kit?
.
http://www.roughcountry.com/gm-suspension-lift-kit-270n2.html
.
Curious about the shocks. When I "priced out" a kit where I purchased each component separately, the cost of shocks alone (Bilstein 5100's front and rear) was more than this entire kit.
.
For those who have experience with the Rough Country shocks, are they decent? I don't mind spending the extra $$ for better shocks if it gives me a better ride and longer life.

That's exactly the kit. There's a lot of fart-sniffing and posturing about Rough Country vs the other fashionable brands. But they've been in business for a very long time, their stuff worked fine 30yrs ago and still does.* I think they'll be perfectly serviceable for my (our) casual cruising use. There are 'better' shocks and they cost a lot more.

Rockauto has the Delco factory replacement Z71 shocks for a total of $270. Basically the same price as the Rough Country Leveling / Lift kit. So spacer and keys are 'free' as I figured it.

Give me a few minutes and I'll go measure my rear wheel well clearance for you, see how it compares with yours and what you need to have.




* I also had a set of Rancho RS5000 (9000s? can't recall) adjustables on my pickup, along with their suspension lift (new front coils and rear add a leaf)held up for nearly 200k mi of mostly highway use, occasional off-road excursions. That's on that white pickup in the pics above. But it just has Monroe gasmatics on it now. Been a long time since it's seen anything rougher than a dirt road.

 

[rayra]

Measured from the center of the rear passenger hub.

rear distance 19'5"

front distance 18.5"

And I really wish I'd got the boots first. Going to have to dismount and fight those shocks to put the boots on later.

eta I'm using Yokohama Geolanders, 265/70-17, mathematically 31.6", so your radius should only be about 5/8 larger. Not 'roomy' in the rear, but totally workable.

 

[justcuz]

Nice job on the write up.
The spring story minus the injury reminds me of installing Caddy Coupe De Ville springs in the front of my 55 Chevy.
Poor mans straight axle!
The 1/2 ton truck, Avalanche, Suburban and Tahoe keys will lift 2500 and 3500 truck due to the different indexing of the keys. Conversely if you use 3/4 ton bars with 1/2 ton keys in a 1/2 ton vehicle it should lift it as well.
Mostly due to the increased spring rate of the 3/4 ton bars, but also the indexing of the 1/2 ton keys.
That's my plan anyway!
My actuator is acting up too. The clicking/thumping of the gear was driving me nuts the other day. Sounds like the blend door is being blocked by something and the actuator is trying to force the door shut and skipping a gear tooth every few seconds.

 

[rayra]

It was a sonofabitch when the missus' driver-zone blend actuator failed in our '05 Tahoe. Very tough to get my big hands on. It's bottom middle passenger side of the dash, about a 1/2" above the floor and forward of the center console. The mounting screws are up in it. It took a slim 1/4" drive short ratchet and 7mm?8mm? socket to get to the screws, very little clearance. But it comes off and goes on easy enough otherwise. Getting the screws restarted was a pain in the ***. Going to the trouble to disassemble and remove the center console would make it a little bit easier but might not be worth the added hassle if you aren't also doing other things to the consoles. (Like adding a power port inside the center console, which I've detailed in another topic)

 

[justcuz]

I'll be doing a heater core, blend door actuator and heater hose couplers out of brass sometime before winter.
Too hot to fool with now! As long as the A/C keeps working, I'm happy.

 

[Bear in NM]

Ray,

Thanks for the warning on the spring compressor. I already had bad thoughts about those, especially having never used one. I'll probably still rent one, just in case, and the picture of your hand will certainly be seared into my brain. My truck has lived in the SW all it's life, and it has no rust. Hoping the bars will come out without too much effort.

Yes, I ordered the parts yesterday, I guess your thread pushed me over the brink, And will plan to do it myself. The repair shops in my small town are notorious for turning 1 day jobs into two week waits.

Thanks for the nudge,

Craig

 

[rayra]

Spring compressor's a good useful tool, used properly. I did several things wrong and paid the price.

The keyhole in the torsion keys is an irregular hexagon, as are the bars. Theirs is not a precision fit, by design. It's more like a 12mm bolt in a 13mm socket, the torsion bars are bound on the edges of the hex ends. Jack the front up on the frame, unbolt the shock and let the lower control hang loose as it can, that takes much of the load off.
Attached the torsion unloader tool and just snug it in place.
Then use an 18mm to back the torsion key adjustment bolt all the way out. With the unloader holding the key in place, the bolt comes right out after a turn or three.
Depending if you'd previously cranked on your torsion setting, you may be able to wiggle out the stop right away. If not, a couple turns on the unloader will allow it.
After that you just unload the unloader and things practically fall apart after that, when there's no heavy corrosion.
Then just reverse the sequence. It's really quite easy to do, in the right sequence you don't have to fight anything.

 

[Bear in NM]

Ray,

Thanks again. I have adjusted the existing bolt and replaced the shocks, so I have the lifting and unloading figured out. Have watched more than a few youtubes on the whole process. The fit of my torsion bar into the key notched looks more like a 10 or 11mm in a 13. I think this wear, on a 14 year old vehicle, is why front is so low.

I did also order the torsion key compressor tool, rather than trying to fabricate something. Between that and renting a spring compressor, I should have the correct tools. I am 53, and have all my body parts. At this point in my life, I either try and do things correctly and pay what I need for tools, or I pay someone else ;^) Although, I installed a new axle on my off road trailer yesterday, and using my floor jack, blocks of wood and my jackstands, the lift was just sketchy enough that I did the install from the outside of the trailer. No crawling around under that house of cards ;^)

Craig

 

[Bear in NM]

Got the 3" Pro-Comp keys on the front yesterday, as well as the 1" Skyjacker spacer on the rear coils. I went very slow and carefully, and the front keys took exactly 3 hours, and the rear two hours. The truck is now up a lot, relatively speaking, and I was able to put on my running boards that I took off last year. I can now crawl under the vehicle from the side, which I was not able to do before the lift, with the boards.

Some thoughts on the process. My truck is not rusted underneath, so it only took a couple of bangs with a 2 lb. hammer to free up the keys from the torsion bars. I did order a proper torsion key clamp, and glad i did. I have seen the you-tubes of folks using c-clamps and fabricated tools. The amount of force required to stack the bars for removal of the keeper is surprisingly low. A small c-clamp would work to unload. But the angle of the pre-load on the new keys makes the installation take a LOT more force to get the keeper back in. It was enough that I heavily lubricated my clamp, and went slow, to keep the heat down. If you have ever snapped a spring and axle c-clamp, you will understand what I was thinking.

As to the rear springs, I did buy a pair of spring clamps, as a just in case. Turns out that unscrewing all of the brake lines and lower control arms was enough to let the springs pull right out, when the axle was lowered. But like the front, the addition of the aluminum puck spacers was enough that they would not slide right in. A couple of twists on the clamps to compress the springs just a tad, and in they went, without worry.

And Ray, I owe you, big. As you noted, and I confirmed with my rig, my heights in the back had a difference of almost 2 inches between the left and right rear. When I installed the new pucks and springs, I swapped them left for right. With a full tank of gas, and me out of the truck measuring, my rear heights are now within a quarter inch, left to right. Very cool.

The test ride with about 1 inch of downward front rake went well. My new keys are in the middle range, but still more than 2 inches of new lift. Potholes and speed bumps, and it rides great. perhaps a tad stiffer, but not enough to say for certain. Definitely not harsh. I'll know more about the steering after I get it aligned this week, but it definitely felt "lighter" in the touch on the test drive. Don't know enough about the physics of the changes in center of gravity that might come from doing this type of thing, but as my truck is 15 years old, with the stock front end probably adjusted and settled some amount lower than when new, I expect the front suspension to feel quite a bit different.

All in all, very pleased. And no regrets spending 150 bucks on tools on a 300 dollar lift. Depending upon how my offroad trailer handles now, I may bag the rear springs. Now that I know how easy it is to get them in and out.

Thanks, Ray, for the nudge to get this done.

Craig