suspension fix for 04 envoy

[kickass audio]

Hello again everyone. I have an 2004 Envoy with 126k miles on it and since I bought it with 100k miles on it the rear end has had a bit of sag to it compared to the front. I haven't measured it yet but I would guess it is like a 1.5-2" drop in the rear. Even before I loaded down the back of my truck with my system it still was down a little. My question is what kind of springs are out there that are heavier duty than the OEM ones for the rear? I can tell my shocks in the rear have seen better days because it bounces quite a bit back there and I will be doing spring and shock replacement and from what I can see on here almost everyone recommends bilstein shocks for the rear. Where can I get better springs at? I was thinking that just doing the spring and shock replacement would help get the back end up higher without having to replace the stock bushings to give a lift. Also I have around 700 pounds of weight in the rear of my truck at all times from my system so keep that in mind. I also do not have the air suspension on mine, just the shock on the outside and the spring in the inside part of the axle.

Thanks in advance for your help guys!

 

[The_Roadie]

For your cargo, I'd put in the traditional '07+ Tahoe/Avalanche Z71 springs we all buy off Ebay. Search for part numbers GM #15234633 or #25978750

The master thread about ALL the insane part numbers of front springs available on OEM vehicles is here: offroadTB.com - View topic - Factory Spring Part Numbers & Associated Lift

I'm not sure we did a chart for rears. Just get the Z71 coils.

And for variability, definitely put in Airlift1000 bags inside those Z71 coils.

** AirLift 1000 Air Bags - Air Lift 1000 Air Bags for Coil Spring SUVs and Vans | Air Lift Company

Part # 60779 - For STOCK Trailblazer/Envoy/etc Rear Springs
Part # 60769 - For Avalanche/Tahoe/ Rear Springs

 

[kickass audio]

which one of the z71's should I buy for the rear? the 15234633 or the 25978750 part number? The 15234633 ones look kinda like the springs for the front. oh and here is the one I found on ebay: 07 11 Tahoe Coil Springs New OEM Suburban Yukon | eBay

thanks for the fast reply Roadie. you are the man

 

[djthumper]

They are rear springs he didn't give any front spring numbers.

 

[kickass audio]

I was just curious what the difference in numbers are for with the springs, that's what I was asking

 

[The_Roadie]

GM obsoleted the lower part number. Nobody knows why or if there's a technical difference. It might have been a supplier change only. It may be an insignificant change in the plastic coil cover. I don't know, so I suspect nobody knows.

Time was, the Border Patrol was buying a fleet of new Tahoes and with zero mileage on them, paying aftermarket companies to lift 'em. So there was a hundred sets of zero mileage takeoff springs on the market, and we were getting them for as low as $35 a pair shipped! Now they seem to be $100 a pair plus shipping. Wish I had done what I said I was going to do and bought 50 of those sets to corner the market.

 

[kickass audio]

aw man thats a steal of a price. I wish I knew about that when it was happening. Well I put in an offer, hopefully I get them if not then I will buy it outright. Thanks again for your help guys! Its much appreciated.

One last thing though, spring compressors. I know its talked about on here a lot but which place have you guys had a good experience with renting one from? I have an advance auto, autozone, carquest near me that I can get it from but am not sure on the quality of the tool and don't want to lose a limb taking these off. Anybody have good experience from any of these stores?

 

[lint]

If your talking about the rear springs, No spring compressor needed , just jack the frame up a little take shock off, Jack up more kick or pull springs out. and take loose the brake line bolt on the shock or frame ''not sure of location'' not to pull lines to tight.

'' Oh Sorry those springs are longer ,May need to compress them some.''

 

[kickass audio]

I had a friend of mine suggest to jack it up a little to support the rear end and take off both shocks then lower it down a little and take off the springs without any compressors. Then put the new springs in and jack it up a little at a time while lining it up and put my shocks on and be done with it. Seems doable.

edit: I don't think it matters since Roadie said somewhere else that these springs are the same on both sides but will the blue plastic cover face down on the truck? like should that part of the spring be close to the axle?

 

[The_Roadie]

The blue plastic is installed upwards on the Tahoes, but engineering-wise it can't possibly matter which end is up. The purpose is to cut down some coil-clanking noise when those coils fully compress and start touching each other. The Tahoe springs are progressive/variable while the OEM GMT360 coils are constant rate, so the coils all touch at once when they're fully compressed. Which should never happen because the bump stops hit the axle first.

 

[kickass audio]

Luckily I have never truly bottomed out on it. I have only scraped the living death out of my mudflaps in the back, a few little scrapes on my hitch under the ball and a minor brush on the spare tire. The back end bounces a lot when I stand on it and bounce so it really seems like the shocks are shot on it for the rear and even if they weren't id still replace them since im doing the springs too. So I guess I will install the springs with the blue covers facing upwards.

Since you are the all knowledgeable guy on here, can you see me having any problems with removing the shocks first then dropping the axle down some to get the OEM springs out and then if needed drop it a little further to get the new tahoe springs in?

 

[djthumper]

Luckily I have never truly bottomed out on it. I have only scraped the living death out of my mudflaps in the back, a few little scrapes on my hitch under the ball and a minor brush on the spare tire. The back end bounces a lot when I stand on it and bounce so it really seems like the shocks are shot on it for the rear and even if they weren't id still replace them since im doing the springs too. So I guess I will install the springs with the blue covers facing upwards.

Since you are the all knowledgeable guy on here, can you see me having any problems with removing the shocks first then dropping the axle down some to get the OEM springs out and then if needed drop it a little further to get the new tahoe springs in?

There should be no problem doing that since that is what we do to get the spacer in there with the springs for our lifts.

 

[kickass audio]

even without me compressing the new springs it will be okay? Sorry for all the noob questions I never did suspension work before.

 

[djthumper]

You don't have to compress the rear springs.

 

[kickass audio]

okay thank you. Since its just the rear I really don't see how I would need an alignment for it after I upgrade the parts because it would not really throw it off right? I just put new BF Goodrich Long Trail T/A tires on at the end of July and had the front aligned and the rear was perfect. The only part of the alignment that was off was the caster but it was completely centered on both sides so they said because of it that it didn't need to be done for moving the whole rack assembly in place to match OEM specs.

 

[djthumper]

Unless you have hit anything the front end alignment should be fine. The rear isn't figured in for alignment.

 

[kickass audio]

sweet! I figured it wouldn't matter but I know people who lift their GMT have to get adjustable panhard and control arms.

 

[The_Roadie]

Many folks don't get the adjustable rear suspension pieces. The panhard is highly recommended above 3" of lift, and the control arms are mandatory for 34-35" tire diameter, though.

 

[kickass audio]

I didn't think it would be a big need or anything for just upgrading springs and shocks though from what i've been told the bilstein shocks I have coming are the same as most GM shocks they use from the factory. I just hope my truck sits up a little higher because it really is down a lot.

 

[kickass audio]

Okay so I got the bilstein shocks and the z71 springs in the mail today but I was looking around on here some more about the z71 upgrade and some people say that the stock shocks can max out on quick bumps. Do you think I would encounter this with the load I keep in the rear of my vehicle at all times? It always has around 700 pounds in the rear end and will eventually get even more weight in the rear so do you think that it will be just fine for my load or should I have gotten different shocks? I bought these shocks for my rear Bilstein shocks and struts for cars and trucks - Shockwarehouse.com and am planning to install the shocks and springs this weekend. Will the shocks top out on extension? I don't plan to go off roading or anything like that maybe once in a blue moon but nothing intense for off roading and living in WNY there are potholes EVERYWHERE and sometimes I can't avoid them but most of them aren't that deep.

Let me know if these will be fine or if they can cause a problem please.

 

[kickass audio]

Just figured I would update everyone on the outcome. So I got the springs and shocks installed today with my sisters boyfriend to help me out. It was a bit of a task because the rear differential did not have enough clearance with the jack underneath the pumpkin so I had to support the differential where the side of the axle is and then lower it down some more. I apologize that I did not take any pictures but it wasn't that bad to do, I would deff do it with at least one other person to help. Im sure there are other write ups on how to do it but I thought i would share anyways.

1.) I jacked the back end of the truck up by the differential about 6 inches and then supported both sides with a jack stand under the frame
2.) I then lowered down the differential slowly until the shocks bottomed out and I jacked it up a little bit to unbolt the lower bolt first and then I removed the upper bolt one side at a time.
3.) Then I unscrewed the support screw for the parking brake where it mounts it to the frame just to give it a little more room to move when I dropped down the back end.
4.) While dropping down the rear end for some reason my truck was creeping back and was getting close to falling off the jack stands even with the wheels locked with 4x4's on both sides of the front wheels so what I did was get a third jack stand and put it right underneath the trailer hitch hookup and had the truck rest on that as well. That stopped the back end from rocking on the jack stands as I did not feel comfortable with how it was leaning and risking it collapsing on me while underneath it.
5.) With the truck now firmly supported I took the jack and lowered the differential as far as I could but noticed that with the jack under the center of the differential it still had a bit of tension on the springs so I could not rip them out. So what we did was get 4x4's to support underneath the axle while we removed the jack from the center under the differential and we then positioned the jack so it was supporting the axle shaft (if thats what its called, im talking about the part right before it connects to the center pumpkin of the differential where the axle shafts sit into) and in this position I removed both 4x4's from the axle and lowered it down as far as I could. Please note: the sway bar was connected the entire time and I think if you disconnect it that it would be better but I did not do this.
6.) I then got a big pry tool that was about 3-4 feet long and pryed up on the springs where it sits into the platform thats welded on the axle and I pushed the spring towards the center of the vehicle. Be careful when doing this as it will be under a bit of tension and spring when it gets moved to the side.
7.) I had repeated step 6 for the opposite side and had both springs and shocks removed. I then transferred the upper rubber cap that fits on the top of the coil spring to the new z71 springs and pushed up the spring into the top of the frame. Please note there is a little cup that it has to rest in, make sure you are in this, what I did was have it so the spring was tipped on its side a little so the top was in the cup and the bottom was towards the inner part of the axle a little.
8.) Once the top was aligned into the cup I then took the pry bar and pryed the spring up a little bit and had my sisters boyfriend pull the spring towards the outside of the truck to get it to pop onto the support plate that is welded on the axle.
9.) Repeat step 7-8 for the other side.
10.) Move the jack under the center of the differential and jack it up. I first installed the upper bolt for the shock tower and had the shocks hanging in the air. Keep the top screw just hand tight at this point!
11.) Adjust the jack either up or down to make it so you can fit the bottom bolt through the lower part of the shock and then bolt it up. I hooked up one side and kept it hand tight and went to the other side and connected that.
12.) I took an impact gun to the nut on the lower part of the shock tower while holding a wrench on the bolt itself and bolted it down tight. I then took the impact gun to the upper bolt and was done.

This upgrade not only gives me a lot better of a ride but I went from a saggy back end where I was 1/8 of an inch from riding on the bump stops to having another 4 inches of lift from where it was when it was sagging. My shocks were shot, they had pressure but I could depress them by just squeezing them together with both arms and I am not a strong guy so to be able to do that means they were well overdue for replacement. All in all it took me and my sisters boyfriend 3 hours to do but we also had to fix a brake line on my truck because my dad didn't pay attention and mounted the one brake hose upside down so it had a ton of tension on it so we had fixed that and bled the system a little from doing it.

Thank you all so much for your help with this! I really appreciate it. I love this forum!

 

[blazinlow89]

Sounds like an overall good learning experience. Does the truck have a rake to it, or is it level? You could find a set of the front spacers that go in between the upper shock mount and the truck frame to push it up if required. Also have you looked at your sway bar endlinks to see if they need replacement? With new shocks and springs I bet it rides like new.

I had similar issues with the jack stands when I did the lift, I put a 24" level in between the seat and the brake pedal to prevent the truck from rolling. I did all the work alone so I wanted to prevent any chances of bad happening.

 

[kickass audio]

I was just surprised that the truck was backing up when I was lowering the differential. The funny part is that if you look at the front wheels while it was doing that, they did not move one bit, it was not sliding on the ground and the wheel chocks we had used were solid. so idk what was making it lurk back like it was but putting the third jack stand under the trailer hitch receiver was what stopped it from doing it any further. I do have a tad bit of rake but its really not bad for me. I would say maybe 1 inch at most. My sway bar end links do not need replacing as they were brand new about a year ago. That is the reason my one brake line was on backwards. Me and my dad were taking the stock ones off because they were bone dry and the hex key that you fit inside the bolt on the OEM links was stripping so we got out the acetylene torch and torched all the connections on the end links. The problem we ran into was that on the drivers side we had used cement board like what you would use for walls in a house to make it so it is water and mold proof. We had them placed up against the gas tank to prevent the heat from melting the tank or making it get too hot and burst into flames. Well the problem with that was that the torch's flame got on the brake line and melted the rubber and once I stepped on the brake after it was done it burst. We had put a new rubber hose on it and he was rushing so he put it on so instead of the line looping upwards it was looping downwards. smfh.

Anyway we replaced them with the moog ones, yeah go ahead and say it, they suck because they are not 100% sealed but I didn't know that part at the time so when these kick the bucket I will get the higher end ones online that are sealed.

The back end is nice for how high it became. Before the upgrade the bumper would be down at the middle of my femur and now it is right near my hip. I also have aftermarket mudflaps that are chewed to shit from the truck bottoming out on driveways and bumps and now they don't even come close to hitting the road on bumps or driveways. I wish I had this upgrade done this summer before me and my friends went on a little beach trip. It was just me and 3 of my friends in the truck with a cooler full of "beverages" haha and a little jetski on a trailer and with every little bump in the road the mudflaps would scrape and it would bounce for a long time after the bump in the road.

 

[The_Roadie]

If you got almost 4" taller, then your OEM springs had taken a permanent set from the overloading. My OEM springs were also shot, even with Airlift bags inside, so finding that the Tahoe/Avalanche Z71 springs fit was a mission saver for me.

 

[blazinlow89]

Wow, those things where shot to hell then. I forgot what heavy systems will do to a trucks suspension, my old S10 Blazer had some serious suspension issues.

The Moog's should be fine, I went with DEEZA ones and am happy with the quality. Plus I like the ability to grease them. I know a lot of people praise the OEM ones, but honestly I do not think mine lasted that long. I want to say around 75k miles and mine were at a very bad point. I was just neglectful. Besides when I can get a set of 4 DEEZA ones for the price of 2 OEM ones, it makes sense. Another thing is when greasing, you need to purge the old grease out, it can take a while and lots of pumping. You need to get the old worn grease out, and wait until clean new grease comes out. This will make the part last twice as long.

 

[kickass audio]

Wow, those things where shot to hell then. I forgot what heavy systems will do to a trucks suspension, my old S10 Blazer had some serious suspension issues.

The Moog's should be fine, I went with DEEZA ones and am happy with the quality. Plus I like the ability to grease them. I know a lot of people praise the OEM ones, but honestly I do not think mine lasted that long. I want to say around 75k miles and mine were at a very bad point. I was just neglectful. Besides when I can get a set of 4 DEEZA ones for the price of 2 OEM ones, it makes sense. Another thing is when greasing, you need to purge the old grease out, it can take a while and lots of pumping. You need to get the old worn grease out, and wait until clean new grease comes out. This will make the part last twice as long.

Yeah they had a sag to them before I owned the truck, I just didn't make things better by adding all that weight from the system to the back. lol. If you are supposed to purge the old grease from the links how can you do that on links that are totally sealed up? Like the Moog ones I have have the grease fitting but the rubber cover for it is like set on so if you pump too much grease in it, it will come out. There are ones out there like the OEM style but that have grease fittings and last I checked if you pump too much into them then it will rip the rubber cover open.

 

[blazinlow89]

Yeah they had a sag to them before I owned the truck, I just didn't make things better by adding all that weight from the system to the back. lol. If you are supposed to purge the old grease from the links how can you do that on links that are totally sealed up? Like the Moog ones I have have the grease fitting but the rubber cover for it is like set on so if you pump too much grease in it, it will come out. There are ones out there like the OEM style but that have grease fittings and last I checked if you pump too much into them then it will rip the rubber cover open.

Sealed links like the OEM ones and some of the aftermarket ones are non serviceable, the only solution is to replace once the part is worn. To purge without tearing the boot requires slow pumping, like I said it take awhile. If it is a huge concern you could use your hand to keep pressure on the outside of the boot. We have some bearing covers on a few of our helicopters that will come off if too much pressure or if it is applied too fast.

 

[kickass audio]

What I meant by sealed is that they have the zerg fittings however the boot is a different design. Like this design: 2002-2009 GMC Envoy Rear Sway Bar Link Pair at 1AAuto.com you cannot get the grease to come out of it because the rubber cover is clipped on it. My moog ones however are not, it actually folds over the link.

 

[blazinlow89]

What I meant by sealed is that they have the zerg fittings however the boot is a different design. Like this design: 2002-2009 GMC Envoy Rear Sway Bar Link Pair at 1AAuto.com you cannot get the grease to come out of it because the rubber cover is clipped on it. My moog ones however are not, it actually folds over the link.

Similar to the ones I have, they have grease reliefs under the band around the outside of the link.

More Information for DEEZA BCL605

Not saying all the ones like that have the relief channels.

 

[kickass audio]

Ahh, gotcha. Yeah that is a good thing, I thought the designs like that were only able to top it off a little but not flush it out. I actually have never flushed out the old grease in my joints before so I will now do that. I always just topped them off after awhile. Thank you for the new tip

 

[blazinlow89]

Ahh, gotcha. Yeah that is a good thing, I thought the designs like that were only able to top it off a little but not flush it out. I actually have never flushed out the old grease in my joints before so I will now do that. I always just topped them off after awhile. Thank you for the new tip

No prob. Some will say its overkill, but remember when you are pushing all the old grease out, you are also removing any dirt, debris, metal shavings, worn materials out. You just pump until the grease coming out is the same color as the grease going in. It may all not be necessary, but it is the proper way to ensure you have clean grease for your parts, working on aircraft has made me pretty anal about servicing stuff.

 

[kickass audio]

I hope this isn't considered as bumping an old thread but I just had the z71 springs I installed in my Envoy start squeaking when you compress them. Like if I were to hit a deep bump and come out of it you would hear them squeak. I had sprayed the blue rubber covers that are on the top of the spring with some silicone spray and it stopped the squeaking. Has anyone else encountered this? The springs are far from bottomed out but the top part where the blue rubber covers are you can see that they are almost closed in.

Other than that everything has been working great with the new shocks and springs. I don't see how people say that the shocks can bottom out if you use OEM sized shocks with the z71 springs. Maybe if you don't have a load in the rear it can bottom out but the heavy load in the rear of mine has it about an inch and a half before the shocks are bottomed out from full extension.

 

[blazinlow89]

Over extending the strut or bottoming out literally? I know you have quite a bit of weight with the car audio stuff which is one reason you have no issues with the shocks over extending. I would think they are fine considering the stock shocks are fine with the MarkMC kit, and the Z71 springs add about 1.5" of extra height. If the two were to be used with each other then I could see some problems.

As for the squeak I am wondering if one of your bushings may be the cause. However spraying the springs could be what eliminates this. Someone who has used the springs should chime in soon. I am in the market for them a set of 86's for the front.

 

[kickass audio]

I thought it was the bushing too but I didn't touch any of them yet. I will soon give them a little spray to soften them up because I have NEVER sprayed any of them. I was thinking it could be the bushing for the sway bar because they are squished but not dry, cracking or to the metal. It is 100% the blue rubber that fits over the top end of the z71 springs that was causing my squeaking. I only got the spray on the rubber cover for the spring and not the rubber cup that fits into the top of the spring into the little cup that locks the spring in the top of the frame. I read on another one of the threads on here that they are supposed to prevent from you hearing the springs clack together when you load them down to their max limit but the odd thing is that this part of the spring is compressing first. With mine the spring is compressing from the top down because I was under it and had my dad bouncing up and down the truck off the trailer hitch and I could only see the upper part of the spring compress, the middle and bottom barely moved so to me I would think the blue rubber cover should be on the bottom of my spring since its the last thing to compress on full compression but hey im not a GM engineer after all. lol.

 

[The_Roadie]

Z71 Springs are progressive rate, while our OEMs are constant. The plastic cover should be stopping the coils from touching and clanking on the softer section. The bottom coils should never touch because the bump stop should hit first. I would add the Airlift 1000 bags.

 

[kickass audio]

Thank you Roadie! Again you are the genius. I knew they were progressive but didn't know the top part was the part that should have the covers for them because I thought it was meant to help it from bottoming out on the hardest part of the spring. I didn't know it was for the soft section. The soft section that they reside is damn near bottomed out completely but the middle and bottom is completely fine. I am nowhere near the bump stops like I was with the OEM springs, I slammed into the bump stops all the time with them. Should the covers on the z71's actually squeak like they do? Its a pretty loud squeak before I sprayed some silicone on them and now its totally quiet. I don't know if its just because it took some time to set in on the spring but I had them in for 2 weeks before I noticed an intermittent squeak and tonight it was very loud that I checked it out.

I personally probably wouldn't hear anything if I removed those covers because I always drive around with my music at full volume (yeah I am that douchebag) but I respect driving in the city, at night and at red-lights.

 

[The_Roadie]

I don't know because whenever I put in Z71 springs I take off the plastic. Don't need anything catching mud and sand for abrasion. But I have the Airlift bags so I try to not let the coils touch because overloading is how I damaged my OEM springs. They take a set after a couple of years.

 

[kickass audio]

Update on the squeak. It is the spring scraping on the frame where the spring sets inside toward the top on the passenger side. I have no idea how it happened because it is locked into the little cup that you have protruding from the upper spring location that is on the frame but if you look at the surrounding area it is right up against the spring and when I was staring up at the spring from under the axle it is cocked so the top part of the spring is going towards the front left of my truck. The odd thing with it is that the driver side spring "pocket" is way larger in size. Also when I had the spring installed I first put the top in and turned it to make sure it was locked in the cup before I slid it onto the axle's mounting plate.

Anyone have any tips on how I can correct this? I was thinking to do the same procedure as I did to remove it where I will jack the rear end up with the front end chocked off. Remove the bottom strut bolt and have the strut just hanging there and drop down the entire axle to take off the stress on the spring to fix the passenger side spring. Any suggestions on how to make sure it mates into the mounting hole at the top?

 

[kickass audio]

Lets hope its the last time I post in this thread. Yesterday I had dropped the rear axle down to the max limits of it with the sway bars still connected to it and just turned the spring a little and was able to see that I did not really have it locked into the shallow dent of the spring mount. I was able to pop it in there and I verified that the drivers side was locked in and then I jacked it back up and was fine. I tested it and it is fine now.

One little question with people who have done this, did your back end of the truck almost fall backwards when you had dropped down the axle? I had to use 3 jack stands, one on each side of the frame just under the part where it bends down for the links and then I had a third one under the hitch receiver. I noticed that when I had started to lower the axle with just the two jack stands on each side of the frame that the back of my truck would start to fall down and pick up the front end, almost like it was being pulled down. I don't know if it was because of all the weight from my system being in the rear of the truck or just the axle itself being so heavy and causing the truck to fall.