Welp. Just did the Suncore HD Coil Conversion. My thoughts...

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
So I have been recently having problems with my airbags, so for Xmas Santa brought me the Suncore HD Coil Conversion Kit for my 02 Envoy. I went straight to work on it today, and have some tips and thoughts about it. First, it really is pretty simple. Here are the steps, and they should be pretty much the same for all coil conversion brands.

1) Jack up the frame and put the jackstands as far back on the frame of the car as you can (i actually used two sets of jackstands because that is just alot of weight, and im real nervous about being under cars without lots of supports)
2) Put your jack under the rear diff and jack it up until the tires come off the ground
3) Remove tires (place under the frame as well, extra insurance...)
4) Remove compressor
5) Loosen the black and white compression fittings on the back of the compressor to let the air out of the air bags
6) Lower down the rear diff from the jack stand and remove the bottom nut and bolt of the shocks
7) With the rear end fully down, grab ahold of the airbags from the side of the car and twist them to the left. You may have to fiddle with it for a few seconds to get it to come out, it can be kind of tricky, but just wiggle it around while turning and they should come loose.
8) Remove airbags, and replace them with your new springs (tightly wound coil end facing UP!). Make sure to have your bushings in place as well. I had to use a crowbar to persuade the springs into place, but not really to tricky.
9) Now your pretty much done, just jack the rear end back up, put the bolt back in the shocks (or replace shocks if need be), then put tires on and remove jackstands. As for me, I bolted the compressor back where it was and just unplugged the #1 Fuse (ECAS??) under the engine fuse block that controls the air ride so. You can remove it just as easily, I just chose to put it back. No harm, no foul, it will not run w/o the fuse in there.
10) Your done, drink a beer and relax! And realize that it really wasnt that hard after all.


A few more things, I didnt measure before and after, but my car definitely sits lower now than it did before (the rear). Anybody got an explaination? My Bilsteins are original w/ 120,000 miles on them, could they be worn out and be causing the car to sit lower now? I actually kinda like the look of it from the side, the car looks much more level than before with the ass hanging up in the air so much higher than the front, except now the rear looks kinda weird as its way lower than before. Ill try and take a picture tomorrow if I can. Also got a boat load of other maintainence done on it....Fuel Filter (had original filter on it lol), Transfer Case fluid change, front and rear diff oil changes. Now all I need to do is the throttle body clean, new serp belt (present one kind of cracked a little), and new spark plugs (not sure if ever changed as well), and tires and it will be like new! Good day for the Envoy!
 

Wooluf1952

Member
Nov 20, 2011
2,663
Milwaukee, Wisconsin
Shocks have no affect on ride height.
Also, only use AC Iridium 41-103 plugs.
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
Is it normal for envoys with coils to ride lower than those with air suspensions? Like do the ones that come stock with coils ride lower than the Air Suspensions?
 

Voymom

Member
Feb 3, 2012
2,523
CReynoldsMIZ said:
Is it normal for envoys with coils to ride lower than those with air suspensions? Like do the ones that come stock with coils ride lower than the Air Suspensions?

My truck did not come stock with air bags, however I have seen 2 envoys, unsure of year, at a stealership with stock air bags and they looked to me as abnormally lower than mine, although im almost 100% sure one of the trucks had issues because it looked as if the rear tires were going to pop out of the trunk, as the body looked like it sat right on the rear tires.

Im going out on a limb to say yes...they do appear to sit lower than a truck without stock airbags.
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
The sensors for the air bags could be adjusted up and down perhaps 2", so I wouldn't make any general conclusions about ride height. It is what the owner wanted it to be.
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
Roadie. So would it be possible to add a spring spacer or something to increase my ride height a little if I wanted to? I was under the impression the air ride was pretty much just determined by the computer, I didnt think it was customizeable? It rides well, just a little lower than im used to, and I tow sometimes, im worried about loading the car down on a trip w/the jet skis and it being too low. I guess maybe i shoulda just replaced the bags :smile:
 

BRomanJr

Member
Dec 9, 2011
371
CReynoldsMIZ said:
Roadie. So would it be possible to add a spring spacer or something to increase my ride height a little if I wanted to? I was under the impression the air ride was pretty much just determined by the computer, I didnt think it was customizeable? It rides well, just a little lower than im used to, and I tow sometimes, im worried about loading the car down on a trip w/the jet skis and it being too low. I guess maybe i shoulda just replaced the bags :smile:

Do you have the Short (SWB) or Long Wheel Base (LWB)?, the springs you have may have been sized for a SWB with average load. Yes, there should be an isolator rubber on top of the spring, and yes, you could add a spacer to the bottom for lift.

In my experience, the air suspension normally sits slightly lower than an unloaded spring setup because the air suspension system keeps the back at a steady height which keeps it from sagging. With springs you need to be a little high when unloaded to allow for loading.

The air suspension is meant to set at a certain ride height from the factory and reset to that point after any service. But it is "adjustable " if you want it higher or lower.
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
CReynoldsMIZ said:
Roadie. So would it be possible to add a spring spacer or something to increase my ride height a little if I wanted to?
I have some left-over 1" rear spacers you could have cheaply, or if you want adjustability, there are Airlift1000 bags that can go inside the coils and you can add a compressor or just inflate them manually when you need a bit of boost. On the Roadiemobile, I put in Avalanche/Tahoe Z71 springs, a 2" spacer, AND the Airlift bags, but then I'm looking for as much ground clearance as possible for the trails.
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
BRomanJr said:
Do you have the Short (SWB) or Long Wheel Base (LWB)?, the springs you have may have been sized for a SWB with average load. Yes, there should be an isolator rubber on top of the spring, and yes, you could add a spacer to the bottom for lift.

In my experience, the air suspension normally sits slightly lower than an unloaded spring setup because the air suspension system keeps the back at a steady height which keeps it from sagging. With springs you need to be a little high when unloaded to allow for loading.

The air suspension is meant to set at a certain ride height from the factory and reset to that point after any service. But it is "adjustable " if you want it higher or lower.

I have the SWB model. I do have the rubber isolaters on both the bottom and top of the spring. Definitely i would say it is about an 1.5" lower than with the air ride.

the roadie said:
I have some left-over 1" rear spacers you could have cheaply, or if you want adjustability, there are Airlift1000 bags that can go inside the coils and you can add a compressor or just inflate them manually when you need a bit of boost. On the Roadiemobile, I put in Avalanche/Tahoe Z71 springs, a 2" spacer, AND the Airlift bags, but then I'm looking for as much ground clearance as possible for the trails.

Hmm, roadie I will definitely keep the 1" rear spacers in mind, although it was weird. When installing the coil I really had to push it in there and use a crowbar as leverage to get the spring up into its position, and that was with the shocks off and the rear end dropped all the way down, yet the air ride had lots of room to drop down. I have heard about these z71 springs alot, and im wondering if i should have gone that route. I heard they were alot cheaper than the 200 bones we dropped for these ones. I attached some pictures, im not really one for liking lowered cars, but i actually think mine looks alot better at its current ride height with the coils, it doesnt have the ass end sticking up in the air anymore :thumbsup: . I always thought that if anything, i would level out the front of the car with some spacers and maybe put bigger tires under it. But now, i think ill just stick with what i got, and drive this car til the wheels fall off, and then someday I can put the lift and tires on a Duramax or Rubicon!!! Tell me what you guys think of the new height!
 

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RayVoy

Member
Nov 20, 2011
939
It looks, to me, that you have a little rake. Normally, the rear is about 2" higher that the front. If your air suspension had it higher than 2" it was probably adjusted wrong.
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
RayVoy said:
It looks, to me, that you have a little rake. Normally, the rear is about 2" higher that the front. If your air suspension had it higher than 2" it was probably adjusted wrong.

Sorry for my newbness, but what is rake?? Here are a few pics of it before (note/; the driveways are definitely sloped way more than the previous pictures where it was pretty flat ground). Its hard to tell on these pictures, especially the first two, because the driveway is so slanted, but i think you can tell that the rear was def higher than it is now.
 

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RayVoy

Member
Nov 20, 2011
939
The rake is the perceived angle when comparing a line on the body with the surface the vehicle is parked on.

The body line is a subjective thing, in your case I used the chrome trim and the space between the top of the tires and the top of the fender arch (compare the front wheel to the rear wheel).

I don't see the rake in the 2nd set of pics, but the driveway is slopped.
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
so here is where im at. you guys said usually the rear is about 2" higher than the front. I measured it out, and right now my rear fender well sits at its highest point sits at 32.25" and the front at the highest point sits at 32" both sides were exactly the same (both fronts 32", both rears 32.25"). What do you guys think about these numbers?
 

RayVoy

Member
Nov 20, 2011
939
That is where a lot of us want our trucks to be.
The only time my Envoy sat "level" was when it had a heavy load in the rear. Mine was empty, or very light loads most of the time, I was always going to replace the springs to lower it to level.

However, you said you tow a little, if the tongue weight is not high, you should ride ok, if the weight is high, you should use a weight dist hitch anyway.
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
RayVoy said:
That is where a lot of us want our trucks to be.
The only time my Envoy sat "level" was when it had a heavy load in the rear. Mine was empty, or very light loads most of the time, I was always going to replace the springs to lower it to level.

However, you said you tow a little, if the tongue weight is not high, you should ride ok, if the weight is high, you should use a weight dist hitch anyway.

Yeah, i just always hoped it would level out when i put some spacers in the front, not lowering the rear. Oh well...:undecided:
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
the roadie said:
I have some left-over 1" rear spacers you could have cheaply, or if you want adjustability, there are Airlift1000 bags that can go inside the coils and you can add a compressor or just inflate them manually when you need a bit of boost. On the Roadiemobile, I put in Avalanche/Tahoe Z71 springs, a 2" spacer, AND the Airlift bags, but then I'm looking for as much ground clearance as possible for the trails.

Roadie. Got a quick question for you. Can you use the airlift1000 bags with the original air suspension compressor. I was thinking, if you install the bags with the original compressor then wouldnt the bags get me back to my original ride height since the original sensors would shut it off when it reached its height? I ask because i pulled a trailer with my quad and plow on it, and the car seemed to sag quite a bit. I did leave the compressor on the car, but just unplugged the fuse so that way if i want i can put the fuse back in and use the compressor in an emergency situation or to pump up tires, balls, etc. What are your thoughts on this?
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
CReynoldsMIZ said:
Can you use the airlift1000 bags with the original air suspension compressor.
Interesting question, but no. The OEM air bags support the entire weight of the vehicle and are a lot more robust (until they die). PSI probably goes up to 100-120. The Airlift1000 bags are helper bags inside coil springs, and their PSI has to be controlled between 5 and 35.
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
the roadie said:
Interesting question, but no. The OEM air bags support the entire weight of the vehicle and are a lot more robust (until they die). PSI probably goes up to 100-120. The Airlift1000 bags are helper bags inside coil springs, and their PSI has to be controlled between 5 and 35.

Hmm, okay. I was thinking if i just adjusted the sensors so it would be down further, then it would hold lower pressure. So now that im kinda dissappointed from the springs and the height...how much for the 1" spring spacers ya got? That is, if you were serious about selling them. I just want a little more lift
 

corvettebob

Member
Jul 9, 2012
9
CReynoldsMIZ said:
So I have been recently having problems with my airbags, so for Xmas Santa brought me the Suncore HD Coil Conversion Kit for my 02 Envoy. I went straight to work on it today, and have some tips and thoughts about it. First, it really is pretty simple. Here are the steps, and they should be pretty much the same for all coil conversion brands.

1) Jack up the frame and put the jackstands as far back on the frame of the car as you can (i actually used two sets of jackstands because that is just alot of weight, and im real nervous about being under cars without lots of supports)
2) Put your jack under the rear diff and jack it up until the tires come off the ground
3) Remove tires (place under the frame as well, extra insurance...)
4) Remove compressor
5) Loosen the black and white compression fittings on the back of the compressor to let the air out of the air bags
6) Lower down the rear diff from the jack stand and remove the bottom nut and bolt of the shocks
7) With the rear end fully down, grab ahold of the airbags from the side of the car and twist them to the left. You may have to fiddle with it for a few seconds to get it to come out, it can be kind of tricky, but just wiggle it around while turning and they should come loose.
8) Remove airbags, and replace them with your new springs (tightly wound coil end facing UP!). Make sure to have your bushings in place as well. I had to use a crowbar to persuade the springs into place, but not really to tricky.
9) Now your pretty much done, just jack the rear end back up, put the bolt back in the shocks (or replace shocks if need be), then put tires on and remove jackstands. As for me, I bolted the compressor back where it was and just unplugged the #1 Fuse (ECAS??) under the engine fuse block that controls the air ride so. You can remove it just as easily, I just chose to put it back. No harm, no foul, it will not run w/o the fuse in there.
10) Your done, drink a beer and relax! And realize that it really wasnt that hard after all.


A few more things, I didnt measure before and after, but my car definitely sits lower now than it did before (the rear). Anybody got an explaination? My Bilsteins are original w/ 120,000 miles on them, could they be worn out and be causing the car to sit lower now? I actually kinda like the look of it from the side, the car looks much more level than before with the ass hanging up in the air so much higher than the front, except now the rear looks kinda weird as its way lower than before. Ill try and take a picture tomorrow if I can. Also got a boat load of other maintainence done on it....Fuel Filter (had original filter on it lol), Transfer Case fluid change, front and rear diff oil changes. Now all I need to do is the throttle body clean, new serp belt (present one kind of cracked a little), and new spark plugs (not sure if ever changed as well), and tires and it will be like new! Good day for the Envoy!

I have a 2004 XUV doing the same thing, is there any warning light on the dash like the newer ones have???
 

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