2500 Avalanche/GM product Leveling kit
 

So, I finally found my 2500 Avalanche, Loaded 2002 95,000 miles, leather sunroof, heated seats, 8.1L. 3.73:1
What is the best way to level the front end? Torsion cams, spring spacers or coiled shocks? I have been on the truck forums no one seems to agree over there.

http://www.roughcountry.com/gm-level...-kit-8592.html
http://www.bilsteinus.com/fileadmin/...WebArticle.pdf (don't know if available for 2500 series)

Also, I have a friend that has a set of 2" wheel spacers that he will give me but they are aluminum not steel. They are used; When I indicate them they are concentric and seem to have no issues. Opinions?

how much does it need to come up ? you can get it up a good bit by cranking up the adjusters, jack it up 1st to take some load off, lube the bolts, long breaker bar 18mm socket most you can get close to 2" out of, alignment needed after

I had a Avalanche 2500. I recommend "keys" for the front to level. Cranking the torsion rides hard. I have aluminum spacers. I really didn't notice much difference with them on. I had 137k on mine. I did a Hypettech tuner and it really helped performance, gave me another 500 rpms on the 8.1 and you need it when towing.

I also replaced the shocks with new Bilsteins at 110k and wow- really helped.

Check out truck and van specialist between zeeland and Hudsonville on Chicago drive they will take good care of you. I have used them a few times, they did a leveling kit for the last 3500 I had and I plan to bring them my last dually I just got.

I would go with new keys for anything more than 1/2" of front end lift. The aluminum spacers should be fine, but you will see a much better overall towing stability increase if you dump those factory pizza cutter wheels/tires. Maybe keep them for winter, but go to an 8" or 9" wide wheel for summer/towing.

I put up a lot of posts years ago on mods to my Avalanche 2500.

I prefer the DiabloSport PowerTuner over HyperTech now. I've had both.

Also, you need to dump that factory hitch. It's garbage. Go to a true Class-V hitch and you will be golden.

This should fit it:
http://www.ebay.com/itm/CURT-Manufac...3e5bab&vxp=mtr

I had a Curt hitch on mine. They are out of business now, but used to make a fantastic product.

I've been through your post. That is a lot of the reason I went with the Avalanche 2500.
I am kind of surprised with the mileage I have seen. On my trip home 176 miles; 112 miles at ~60 mph Highways and 64 miles at 72 mph Expressway = 16.07 mpg and the last 209 miles daily driving, city, highway and towing the Scarab 30 miles = 12.77 mpg. I do drive with a light foot. I did see 9.97 mpg with 143 miles city and little highway driving, expected. This is all hand calculations.

I just bought a Curt for my Cadillac STS so I can put my bike rack on my car.

Thanks everyone, I think I'm going to buy this kit and have my brothers shop install it. Then I will get the new rims and tires. I plan on keeping this for a while.
http://www.ebay.com/itm/2-5-LEVELING...0defdc&vxp=mtr

For the leveling it, get new torsion keys. If you just crank them, it will eat tires even with being aligned.

I just got a new Curt hitch this Spring rated at 16k for my 2500HD. Eastern Marine was cheapest by far and it was drop shipped free.

raisint the front end your going to find that the rear will now sag..i do the shocks and keys,,have them ship you the longer shocks for the rear and add a leaf..it will handle the tongue weight better as well. it will raise the ass 2 ''

too bad you found one, I just put my 03 2500 AVY up for sale this weekend!

http://saginaw.craigslist.org/cto/5239646159.html

FWIW I have a 2" torsion key leveling kit in mine and it worked perfectly. I would never just crank the bars to get more lift without keys, did that once on different truck and rode like crap. I did the 2.5" front keys with shock extender brackets and 1" block in the back.

If you are interested, I have a brand new in box Trailmaster 4" (Bought out BDS) suspension system for the 2500 AV/Burbs that I am selling as well. Full drop knuckle kit with shocks $1250 all stamped "Made in USA." I also have the Cognito upper control arms new in box with ball joints for another $500. This combo would give you a mid-travel suspension kit with improved geometry. PM me if you are interested.

That may be because you have the taller gear set. Most of them had 4.10 rear ends which make them stump pullers but at the cost a few MPG's. I have 4.10 and I get 13 mpg normally and 9-10 mpg towing.

There is absolutely no difference in cranking the torsion bars vs different keys. The only time you need keys is when there is no adjustment left in the adjuster bolts. What is done in either case is an rotational adjustment...there is no loading the keys any differently. No matter if keys or adjusted or replaced with offset hex keys...if it goes up in front the truck will need alignment. And really, going up an 1" is about as much as you want to go as the tie rod ends will be pushing on the Pitman and idler arms at off angles which will prematurely wear them out. Also if longer shocks are not put on they stockers will top out and self destruct.

I have done multiple lifts on torsion bar trucks, a true lift the only correct way to go up on that style suspension. A knuckle type lift is the only way to go.

I was going to mention this Jrider but you know how the bashing goes I will shut up .

Mine was the 4.10 and I NEVER got 16 mpg. Saw 14 one time on the highway driving to my sisters in Indy at 65 mph.... I went nutz because it turned a 4 hour drive into a 5 1/2 drive.

If your towing a boat then I highly recommenf the Firestone Air Bags.

Wannabe

See post 12

I thought the cranked torsion bars rode worse than a truck with keys until I put my first set in and understood how they worked.

The one thing you have to be careful about is a lot of people that put keys in, will then crank them to achieve even more lift. Best case scenario, the ride suffers. Worst case scenario, stripped out axles and failing shocks.


As far as MPG, I have a 2500HD. I think the Avalanches are capable of better MPG due to the different tranmissions. That being said, I've never hit 13 mpg with my truck in 4 years of ownership.

Cranked torsion bars and/or keys will make your front end ride rough. If you want to do it right and keep the factory ride then this is what you need. Replacing the shocks and upper control arms will keep everything as close to factory but with the added ride height.

http://www.cognitomotorsports.com/co...ocks-1319.html

I have the 4.10 gears as well. I can pull 16-17 mpg easily up to 60 mph. Above that it tanks with the gears. 65+ mph highway is 11-12 unloaded and 10-11 pulling. I averaged 10.4 pulling to Kentucky and back. Not too bad really. Weight has almost no bearing on MPG with mine, but holy cow does wind resistance of whatever you are pulling or if there is a head wind.

on a half ton,,they ride better but on a 3/4 ton with the
kk tortion bars my suburban rides like ****...put the keys in and it rides like a caddy now..

THERE IS ABSOLUTELY NO DIFFERENCE BETWEEN CRANKING THE TORSION BARS OR INSTALLING DIFFERENT HEX KEYS. EITHER WAY YOU ARE CHANGING THE POSITION OF THE TORSION BAR. THIS IS SO BASIC. My guess is you installed new shocks with the keys that give it more drop out....either way it's a ****ty way to lift a truck. I'm done here.

JRider is correct. All that you are doing either way is just turning the torsion bar a little further. There is ABSOLUTELY no difference between cranking them up or installing another key to raise them up.

I had a 2003 Avalanche 2500 8.1L for 8 years put 110K miles on it , never had an issue with it.
The best way to level any 4X4 is to lower the rear, not raise the front.... IMO
Just get a set of 2in Lowering shackles from Belltech for $100 that move the rear leaf springs further up toward the bed. Very easy install and cheap.
Also had 2in Hubcentric Aluminum wheel spacers for the rear to make the rear track equal to the front. Looked much better.

It will ride like $hit because the upper control arms are bottoming out on the frame stops even with extended shocks or extended shock brackets. The only way to restore factory ride is with different upper control arms. I went with Cognito control arms and the truck rode like factory. They also allow you enough camber and caster adjustment to get your alignment to factory specs. Unfortunately their upper ball joints don't seem to last so well as the truck has been through two sets of uppers since the control arms went in. The boots allow water into the joint. and it rusts the ball and socket.

[img]img_0240.jpg[/img]

weather you change the keys or crank them up you are doing the exact same thing, raising the spring rate of the bars, any change in suspension height will need the alignment redone, doing it the "cheap" way without some way of relocating the controls arms to gain lift you must raise the spring rate. Now great thing about this setup is you can try it easily and see if you like the ride, if not return it back and roll on, just count the # of turns that you give the bolts..

Still not changing the rate of the spring, the only way to do that is to change the spring/bar. A better word for Cranking the bars is Adjusting.

sorry, you are wrong, when you crank up the adjusters you ARE changing the torsion(spring) rate.

Check out offroad unlimited. I used the ORU leveling keys on my 03 8.1. What I liked the best was the keys came with new proper length Bilstein shocks, instead of cheezy drop brackets. My crewcab hd, sat pretty level with the level kit and the boat on behind. Had I kept the truck I would have put air bags on the rear but that is because all my trucks rear springs have a tendancy to slowly loose how well they "handle" weight, because they are constanly overloaded hauling things they shouldnt be.

Good luck with the 8.1. I miss mine, especially everytime it comes to repair my ford 7.3 diesel. Something I found that was nice for the 8.1, find the quicky lubes that offer free top offs between oil changes. My 8.1 ate 1 qt every 1500 miles. When I hit 3,000, it was time to get it changed anyway. They are beasts. Have fun

http://i63.tinypic.com/255m16d.jpg
This pic does not show it very well, but I had the wrong height hitch on the truck, once I raised the hitch the truck sat level with the boat on behind. The tires/ wheels were 285 goodyear duratracs, on some 16x8 aluminums that were on my plowtruck. They were not my first choice in wheels but I had them left over from another truck. They did widen the stance a bit over the factory wheels. another plus is the bolt pattern is still the old school 8x6.5. Those wheels on that 8.1 had been on 87 chevy 3/4ton, my 95 gmc 3/4 ton (with ford axles) , my 88 gmc 1 ton, and my 86 3/4ton.

Another decent looking wheel that can be had pretty cheap is the factory alumn. ones that came on the 95ish-97 f250, f350 fords (pre superduty). I want to say they are forged alumn alcoa wheels that were 16x8, and the same 8x6.5 pattern.

You are changing the position of the torsion bar and A-arm respectively, you NOT changing the rate of the spring (bar). It is physically impossible to change the rate. I am all ears if you can explain it but I paid attention in physics and have special interest as I tune my own sled shocks.

https://www.google.com/search?q=spri...utf-8&oe=utf-8

http://www.gmfullsize.com/tech/torsion401.html

You are putting more pre-load on the torsion bars which are a progressive rate spring in them selves.

http://www.cognitomotorsports.com/ch...eling-systems/

+1 for Cognito to level it. UCA's are definitely the best way. I have an 2003 2500 but I lifted it with their 7-9" kit. Tows great and no sagging towing my 32. Also look into their steering upgrades... well worth the money. http://www.cognitomotorsports.com/ch...ring-upgrades/

The A-arm moves in relation to the adjuster. There is no more compressing of the spring as in a coil spring. The only time the bars can possibly be preloaded more is at suspension top out when the A-arm is on the drop out pad (which would be quite a $hitty ride). The bolt on the key is nothing more than an adjuster. Torsion bars are linear NOT progressive. I am not being a smart ass here, I just do not like misconceptions.

Check out the Advantages and Disadvantages section.
https://en.wikipedia.org/wiki/Torsion_bar_suspension

torsion bars are the springs, when you tighten the arm adjuster you are twisting the bar which is your spring rate, the front end has bounce right ?? no coil or leaf springs right ? when you tighten the bars it raises the spring rate therefore raising the vehicle, loosening does the reverse. The bars are just twisted to do the exact same thing as a spring, the leveling keys mearly index more twist without running the bold in as far, but doing exactly the same thing...

OK, go under your truck and draw a white straight line all the way down the bar, now move the ADJUSTERS all the way in...does the line twist? NO

Now adjust the adjusters all the way out...does the line twist? NO

You are attempting to say that changing an index gives the bar more twist...it does not work like that. Your A arm moves in direct relation to the adjuster. You are not changing the spring rate either.

let me simplify this, you change the angle of the adjuster and the A-arm angle changes the same. Get it?

WOW, how can something so simple be so confusing. When you screw the bolt in on the back of the torsion bar, all that you are doing is rotating the bar, PERIOD. To add "preload" to it, you would have to add more weight to the front of the vehicle and to "change the spring rate" you would have to change out the torsion bars. Whether you change out the keys or adjust the factory ones doesn't matter. The lower control arms cannot tell the difference.

go to look up torsion(means twist), also where do you think the spring for the front end comes from ?

Me and Snap are saying the same thing, you are not following it. After initial loading of the bar with the weight of the vehicle, the bar only "twists" more under suspension compression. I think you are the one who needs to go look up torsion.

really...try this one last time...each end of the bar has a hex, one fits into control arm, the other into the key, when you tighten the adjuster bolt you twist the the bar, the more you tighten, more twist, more spring rate as you push the control arm the oppisite way from the adjuster key

The sky is green. Pancakes. I like pancakes.