'98 K1500 Front Coilover Swap

[jd33173]

I've been reading post on this site for a couple years while I restored a coveted obs Z71. I thought it was time to go ahead and register.
Any way...... here are a few pictures of my tuck. It is a complete frame off restoration. The only thing left to do is the headliner.
I've also wondered how swapping in a set of coil overs would work. It would be easy enough.
You guys mostly talk about not gaining articulation and then proclaim that a coil over conversion would therefore not be worth doing.
You realize that these trucks are not rock crawler buggies and that gaining articulation has little to do, if anything, with why a coil over suspension set up would be desirable, right?
Saying that, leads me into my next question.
While i do occasionally find worthwhile information on this site most of what i read sounds like kids trying to ruin there first truck with ridiculous modifications and children that have absolutely no idea what they are talking about.
Also, the site seems saturated with members that can barely read or write much less form complete thoughts and type those thoughts into a paragraph that is understandable.
Is this what this site mostly is?

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Nice truck, that being said, your post is you basically asking for a can of verbal whoop-a** to be opened upon you. I enjoy reading the posts here, this forum is populated by a bunch of very experienced and knowledgeable folks. There are some crusty folks on here, and i enjoy them too as they are sometimes highly amusing. Whenever i leave this site out of my research when doing a job on my truck, i am sorry. I dont know what you hope to gain or change you wish to effect by denigrating those who visit and or post here. I encourage you to seek a site more to your liking somewhere else on the internet as we are very busy attempting to form cogent thoughts, and struggle to appreciate how much smarter than everybody else you are.

 

[VASOMM]

I've been reading post on this site for a couple years while I restored a coveted obs Z71. I thought it was time to go ahead and register.
Any way...... here are a few pictures of my tuck. It is a complete frame off restoration. The only thing left to do is the headliner.
I've also wondered how swapping in a set of coil overs would work. It would be easy enough.
You guys mostly talk about not gaining articulation and then proclaim that a coil over conversion would therefore not be worth doing.
You realize that these trucks are not rock crawler buggies and that gaining articulation has little to do, if anything, with why a coil over suspension set up would be desirable, right?
Saying that, leads me into my next question.
While i do occasionally find worthwhile information on this site most of what i read sounds like kids trying to ruin there first truck with ridiculous modifications and children that have absolutely no idea what they are talking about.
Also, the site seems saturated with members that can barely read or write much less form complete thoughts and type those thoughts into a paragraph that is understandable.
Is this what this site mostly is?

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Your wife must have cut you off, is that why you're so hateful and condescending?

 

[dzynda]

Maybe in the "Lifted and Offroad" section IDK

But no, In general it is not at all what this forum is about.
Many internet forums are full of people that seem to get a kick out off pissing on other less knowledgeable members, kind off like you did in the part I quoted above.

This forum is different.
If you spend some time here you might like it. And if you find you know everything already or, have a buddy that does, How about sharing that knowledge in a non condescending way to the illiterate teenagers that don't.
THAT is what this forum is about.

I know this is an old thread and your response was very well said. I get sick of the degradation on these forums when people come here to learn and share.

 

[dzynda]

That being said has anyone done anything with this coilover conversion? I see that some are referring to more articulation and travel I wasn't searching for that. A few reasons that I did my coilover conversions on my k3500 trucks. First my torsion bars were rusted into the keys and arms. Second for a better ride, the difference is noticeable. Third I wanted to air ride one of them and keep it 4wd. I didn't intend to lift them more then to fit 33x12.50 or off road them so articulation wasn't a concern of mine. If you want articulation or lift then I would definitely straight axle swap it which I believe is an automatic 3 inch lift. I prefer stock to lowered, my one truck on air has almost 6 inches of travel on the front. I'm still learning and looking for a better upper mount idea like a shock hoop. I'm considering changing to a hydraulic coilover on the front for better lift and a constant spring rate. This will require a taller shock so an upper mount would need to be fabricated which is not in my wheel house.
As for the lowers arms, I swapped you gmt800 and did the Knuckle, brake conversion. On one set I had the lower brackets welded on, on the other I used bds lower bracket from their gmt800 coilover conversion kit. They will sell pieces individually is built well has an aluminum slug to fill the torsion bar hole and bolts you it. I'll get pictures of it, the air lift coilover bag shocks wouldn't work with that bracket. The air ride was another learning experience especially with the weight of the big block. I have scales and weighed out the truck and this is why I'm now considering changing to coilover hydraulic shocks.

 

[offroadtahoe]

That being said has anyone done anything with this coilover conversion? I see that some are referring to more articulation and travel I wasn't searching for that. A few reasons that I did my coilover conversions on my k3500 trucks. First my torsion bars were rusted into the keys and arms. Second for a better ride, the difference is noticeable. Third I wanted to air ride one of them and keep it 4wd. I didn't intend to lift them more then to fit 33x12.50 or off road them so articulation wasn't a concern of mine. If you want articulation or lift then I would definitely straight axle swap it which I believe is an automatic 3 inch lift. I prefer stock to lowered, my one truck on air has almost 6 inches of travel on the front. I'm still learning and looking for a better upper mount idea like a shock hoop. I'm considering changing to a hydraulic coilover on the front for better lift and a constant spring rate. This will require a taller shock so an upper mount would need to be fabricated which is not in my wheel house.
As for the lowers arms, I swapped you gmt800 and did the Knuckle, brake conversion. On one set I had the lower brackets welded on, on the other I used bds lower bracket from their gmt800 coilover conversion kit. They will sell pieces individually is built well has an aluminum slug to fill the torsion bar hole and bolts you it. I'll get pictures of it, the air lift coilover bag shocks wouldn't work with that bracket. The air ride was another learning experience especially with the weight of the big block. I have scales and weighed out the truck and this is why I'm now considering changing to coilover hydraulic shocks.

Nice work! I looked up ways to do it and stumbled across that bds lower bracket too.I ran across a guy who did it on fb groups I really wish they would post here though. Those post's are hard to find are scattered, have very little details. Here is one i found done on a k1500 with a obs bds lift


I came up with this and left it alone. Since I like the look of mine with the upper control arm drop brackets and already have kryptonite upper arms that likely wouldn't clear a coilovers

Coilover conversion.

GMT800 2500 HD lower control arms (or just use GMT400 forged lowers and redrill the shock bolt portion on the bracket)

BDS gmt800 lower control arm to coilover mount

6- lug 6.5" lift custom spindle. with the GMT800 lower ball joint taper and the GMT400 or GMT800 2500HD upper ball joint taper. To have the correct spindles for my 6.5" subframe drops.

Upper control arm mount spacing cut and reweld to be able to use the 8-lug GMT800 HD BDS kit upper control arm

Maybe use coilovers from the kit or source some from atomic.

This would likely be easier for most if they went to GMT800 knuckles but not me since I run 15" wheels and also want to stay 6-lug.

(I know for 3" lifts it's easier.) As far as I remember, it has been a while.

 

[dzynda]

That's nice work, I'm not to great at fab work so a lot of mine has been trial and error. 2500 & 3500 Gmt400 & gmt800 are basically the same other than the ball joint. I did the spindle swap so I changed my lower arms to the gmt800 so I didn't have to reem out the spindle. FYI the gmt800 upper ball joint is a pres into the arm style. The gmt400 upper ball joint (6292) fits the gmt800 spindle. The front two bolts line up on the gmt400 2500 arm then you drill out the rear two that don't line up. I did use kryptonite tie rods that cost $379 for both because like I said I am not a good fabricator. This was years ago before they offered them for the gmt400 I had them make them for me. FYI also the cv axle from the 01-10 will fit the 2500 & 3500 gmt400 also if you want to use axiom high articulating cv axle. I've bought bds, skyjacker and Tuff Country lift spindles to see if it worked better so the upper arm wasn't to far down. The bds coilover is 20.8" tall with 5.6" of travel the coilovers I bought were from FOA I believe 18" 650lb springs. The stock spindle works best on my one with air ride. I'm thinking I'm going to try the skyjacker spindle again on my dually because I want a little lift to it.
Stock spindle
13" tall
Skyjacker 01-10 3" lift # C9381
$350 each over all height 15.91"
C938L
C938R
Tuff Country 01-10 4" lift #19485
$263.25 each over all height 17.25"
16985-01 L
16985-02 R
BDS 01-10 4.5" lift #740FDSC
$345 each over all height 18.5"
01178L
01179R

 

[dzynda]

I'm about to possibly do a conversion on a 95 1500. It's a northern truck and needs everything redone and I have a feeling they the torsion bars will be rusted together like my other truck was so I'm thinking just doing that coilover conversion will be best.

 

[dzynda]

Nice work! I looked up ways to do it and stumbled across that bds lower bracket too.I ran across a guy who did it on fb groups I really wish they would post here though. Those post's are hard to find are scattered, have very little details. Here is one i found done on a k1500 with a obs bds lift


I came up with this and left it alone. Since I like the look of mine with the upper control arm drop brackets and already have kryptonite upper arms that likely wouldn't clear a coilovers

Coilover conversion.

GMT800 2500 HD lower control arms (or just use GMT400 forged lowers and redrill the shock bolt portion on the bracket)

BDS gmt800 lower control arm to coilover mount

6- lug 6.5" lift custom spindle. with the GMT800 lower ball joint taper and the GMT400 or GMT800 2500HD upper ball joint taper. To have the correct spindles for my 6.5" subframe drops.

Upper control arm mount spacing cut and reweld to be able to use the 8-lug GMT800 HD BDS kit upper control arm

Maybe use coilovers from the kit or source some from atomic.

This would likely be easier for most if they went to GMT800 knuckles but not me since I run 15" wheels and also want to stay 6-lug.

(I know for 3" lifts it's easier.) As far as I remember, it has been a while.

My questions to you are
1) Did you have to modify your upper shock mounts? You can see I did but I'd rather not
2) Your coilover spring doesn't hit your cv axle? I had to add extensions onto mine which reduced the travel of the shock. I don't really go of road so it doesn't bother my to much.
3) What coilover are you using and it's overall length?

 

[offroadtahoe]

That's nice work, I'm not to great at fab work so a lot of mine has been trial and error. 2500 & 3500 Gmt400 & gmt800 are basically the same other than the ball joint. I did the spindle swap so I changed my lower arms to the gmt800 so I didn't have to reem out the spindle. FYI the gmt800 upper ball joint is a pres into the arm style. The gmt400 upper ball joint (6292) fits the gmt800 spindle. The front two bolts line up on the gmt400 2500 arm then you drill out the rear two that don't line up. I did use kryptonite tie rods that cost $379 for both because like I said I am not a good fabricator. This was years ago before they offered them for the gmt400 I had them make them for me. FYI also the cv axle from the 01-10 will fit the 2500 & 3500 gmt400 also if you want to use axiom high articulating cv axle. I've bought bds, skyjacker and Tuff Country lift spindles to see if it worked better so the upper arm wasn't to far down. The bds coilover is 20.8" tall with 5.6" of travel the coilovers I bought were from FOA I believe 18" 650lb springs. The stock spindle works best on my one with air ride. I'm thinking I'm going to try the skyjacker spindle again on my dually because I want a little lift to it.
Stock spindle
13" tall
Skyjacker 01-10 3" lift # C9381
$350 each over all height 15.91"
C938L
C938R
Tuff Country 01-10 4" lift #19485
$263.25 each over all height 17.25"
16985-01 L
16985-02 R
BDS 01-10 4.5" lift #740FDSC
$345 each over all height 18.5"
01178L
01179R

Thank you for those sizes might just try to coilover swap it.

My questions to you are
1) Did you have to modify your upper shock mounts? You can see I did but I'd rather not
2) Your coilover spring doesn't hit your cv axle? I had to add extensions onto mine which reduced the travel of the shock. I don't really go of road so it doesn't bother my to much.
3) What coilover are you using and it's overall length?

I didn't do the coil over swap in the photo.It's one I saved a few months ago from this guy that did it on Facebook gmt400 groups. I can't seem to find that post anymore.
But looking at the pics i don't think he had to reinforce upper shock mount,I'll see if i can find it still. * edit found it


*Im glad i just looked though I found someone who did it on a gmt400 rough country 4-6" lift drop brackets kit. Sounds like an easy option for me to keep the looks and run 15" wheels but i would use the bds shock bracket,and reinforce the upper since i run 39.5"

How much is that bds lower control arm shock bracket?

 

[evilunclegrimace]

I do not have any experience with these types of mods but I have seen several builds that were along the same idea. They all used ODI struts. I don't know if you guys are aware of them, but it might be worth looking into.

ORI Struts – Stability you can bank on

www.bing.com

 

[dzynda]

I do not have any experience with these types of mods but I have seen several builds that were along the same idea. They all used ODI struts. I don't know if you guys are aware of them, but it might be worth looking into.

ORI Struts – Stability you can bank on

www.bing.com

Huh, those look like an air shock or strut. I've thought about that too eliminate the spring. That's a good possibility, Thank you.

 

[dzynda]

Thank you for those sizes might just try to coilover swap it.

I didn't do the coil over swap in the photo.It's one I saved a few months ago from this guy that did it on Facebook gmt400 groups. I can't seem to find that post anymore.
But looking at the pics i don't think he had to reinforce upper shock mount,I'll see if i can find it still. * edit found it


*Im glad i just looked though I found someone who did it on a gmt400 rough country 4-6" lift drop brackets kit. Sounds like an easy option for me to keep the looks and run 15" wheels but i would use the bds shock bracket,and reinforce the upper since i run 39.5"

How much is that bds lower control arm shock bracket?

OK, gotcha. Any info we keep finding helps, I bought that stuff back in December of 21 and paid about $450 for it. This is my invoice from them minus tax and shipping. I bought the lift spindles also at that time they were never installed them because I'm not lifting the truck if anyone is interested in the spindles. I have the brackets too that are not installed right now that I may sell but not real going to discount it much.

 

[evilunclegrimace]

Huh, those look like an air shock or strut. I've thought about that too eliminate the spring. That's a good possibility, Thank you.

They are nitrogen filled; you can adjust the pressure to adjust how soft/hard you want the ride and also adjust the ride height

 

[dzynda]

They are nitrogen filled; you can adjust the pressure to adjust how soft/hard you want the ride and also adjust the ride height

ORI shortest travel is 8" which has an overall height of 23"
Fox makes a 2.0 that goes as low as 4" travel the 4.5" is 11.79" compressed and 16.29" extended the 5.5" travel is 12.79" compressed and 18.29" extended the stock mounting eye to eye is 12.5 with the truck dropped onto its bump stops and 17" max lift with stock arms and everything attached. This is on 2500 & 3500 I'm not sure about 1500 They cost around $400 each

 

[dzynda]

I remember why I was steered away from air shocks on a daily truck, hope it helps.
This is off of F. O. A. site

If your rig will be driven regularly on the street, we do not recommend an air shock. Because an air shock relies on air pressure and oil volume to set spring curve and rate, controlling body sway is far harder than on a coilover, where you simply adjust the transition collar. Likewise, if you plan to run at fast desert speeds, an air shock is not the right choice. The spring curve comes from oil level and nitrogen pressure, making the shock extremely sensitive to heat.

Motorcycle manufacturers tried air forks and abandoned them for a similar reason: they’re easy to tune for a short moto, but as temperature rises the fork becomes soft and springy. A vehicle experiences the same problem. With coilovers, even if oil temperature climbs and you see valving fade, the steel springs still carry part of the load. When an air shock heats up, you get the same valving fade, but because the oil and air emulsify, the effect is more pronounced. As oil and nitrogen get hotter, the spring rate rises, rebound speed increases—and the hot oil prevents the rebound valving from keeping up—leaving the car soft and bouncy.

Which Rigs Are Right for Air Shocks?
Air shocks shine on vehicles with very light corner weights. The lightest coil springs commonly available are about 100 lb/in. Ultra‑light rigs with large suspension travel often can’t reach the desired ride height with coilovers, even with light dual‑rate or triple‑rate setups. In these cases, an air shock can be set with a lower droop percentage yet a higher spring curve than a coilover, enhancing bottom‑out resistance and “push‑off” in the rocks. These rigs are typically slow‑speed crawlers, so they don’t build much heat. The same applies to extremely light go‑kart‑style buggies—corner weights are so low that coilovers struggle to provide the correct ride.