Sagging rear springs - fix vs. bandaid?

[alrock]

Okay, leaning towards the Bebe/Speedy fix but also with re-arching if necessary. Will have new u-bolts, in part because the old ones are cut to length for the tomp plates and would be too short if a new leaf was added.

What about leaf spring bushings? I can't see their current condition and GM doesn't make them available separately, at least from what I can see. I may have to just reuse what's there and if they are bad then replace them later.

 

[bebe]

They do make them /sell them and I believe I still have a set from my Garage sale that never sold.

Let me check.

 

[Bigunit]

..and I have a brand-new, still-in-the-box set of OEM u-bolts for you!

 

[alrock]

And I ordered four replacement u-bolts to restock your inventory!

 

[bebe]

I have the bushings!!! - they need to be pressed out and back in - so you will need a hydraulic press.

 

[alrock]

Thanks Bebe! I might've missed the opportunity on the bushings as I'll probably do these springs on Tuesday. Don't have much flexibility in the schedule right now and Tuesday works well. Or I wait until August :gaah:

 

[Hans3T]

Is yours a bit rough hans? I'm trying to figure out if there's a difference between a specific add a leaf or adding the 63in Chevy leaf.

Sent from my DROIDX using Tapatalk

Yes, it does ride stiff in the back with the 2 add-a-leaves. One price to pay for the lift...

>Sent using Tapacrack<

 

[alrock]

I think I need the added leaf. Bebe's truck was obviously heavier with the badass bumpers, roof rack, dual ladders, etc. but for for the rest of us some of the stuff we all add is more subtle and adds up over time. I've added UCP, roof rack, ladder, heavier spare tire, extra lights, blow up dolls, rock rails, hi-lift jack, hunner skids which all adds around 400 lbs or more. Then I tend to carry another 80 lbs or so of gear, even when not going off road. That's likely more than the OEM springs were designed to handle on a daily, continual basis. The rear end is sagging about 1 3/4 inches vs. stock. Even if I got new OEMs I should beef them up but I want to try the re-arch and see how that does.

 

[LagunaH1]

Maybe just convert the rear to double A arm independent suspension like, say, an H1? -That way you wouldn't have to remove the leafs and THEN drive to the shop....

 

[4speedfunk]

Having been playing around with my springs for awhile now...I think the SOA mod amplifies this leaf spring problem. I'm not sure why. After all, it seems logical that the springs are in the same situation whether the load is over or under the spring pack. Its the same load...concentrated in the same spot on the spring pack...in the same direction. Still, the springs seems to be more sensitive to vehicle weight with the SOA. There's probably some deeper engineering missing from my simple viewpoint but, that's what I've noticed.

Speedy's mod makes a lot of sense because he added beef to the "initial" spring, and not to the "overload" portion of the spring pack. This is a stark contrast to the traditional add-a-leaf which adds beef to the "overload" part of the spring pack, and does very little until the spring gets compressed. Unlike most trucks, the H3's problem is entirely with the main-spring problem...and its very obvious in the initial (static) position. So I'm hittin the bone-yards this weekend...looking for a 3/4T donor!

I think we off-roaders might be under-estimating the effect of two very common mods that most of us have down: (1) How much extra weight a larger spare adds, and (2) How much extra weight gets transferred to the rear suspension after a T-bar crank. I used to think that all of us H3 guys were complaining about "saggy" rear springs but, I'm started to re-think this problem. I don't think my springs are saggy. I just think their is too much weight on them. I say this because I just installed some brand new GM springs, and they look identical to my 15K mile springs (that I thought were worn-out). I have a heavy THORparts bumper, a heavy spare, some tools, and a nose lift...all of which seems to be simply too much weight for the stock rear springs. Even brand new ones! I have not removed all this stuff to verify for sure...but I'm 99% convinced. BTW...Has anyone actually restored their H3 to a desired ride height with nothing more than installing new GM springs? It didn't work for me.

 

[alrock]

I am rethinking my strategy. I will be getting a second set of springs, used but with far fewer miles and then adding a leaf. I bet I need new bushings too and those are $50 for a set.

By getting a second set of springs I can do this for about the same amount of money with far fewer scheduling headaches

Sent from my VS910 4G using Tapatalk 2

 

[speedy]

I am rethinking my strategy. I will be getting a second set of springs, used but with far fewer miles and then adding a leaf. I bet I need new bushings too and those are $50 for a set.

By getting a second set of springs I can do this for about the same amount of money with far fewer scheduling headaches

Sent from my VS910 4G using Tapatalk 2

That's a good idea.:huh:
Nothing like trying to cram 10 pounds of :hpoopinto a 5 pound bag:giggle:

Let me know if i can help.

 

[MaxPF]

Speedy's mod makes a lot of sense because he added beef to the "initial" spring, and not to the "overload" portion of the spring pack.

There is no "overload" portion - the stack of progressively shorter leaves creates a variable rate spring. An overload is a specific leaf that is normally out of contact with the main pack, and is very thick and thus of very high rate. It only comes in to play of the springs are overloaded with too much weight, or the axle wraps under torque.

The bottom "leaf" in this pack is the overload. You can see how much thicker it is vs the actual leaves above it:

It's not easy to see in this pic, but the overload is flatter, and the ends have a gap of about 1-1/2" between them and the rest of the pack:

With enough weight, the overloads will come into full contact with the main pack, and the rate will increase dramatically. Another advantage is that it severely limits axle wrap - as the axle tries to rotate, it brings one side of the overload into contact with the main pack, acting like a slapper bar and preventing further rotation and distortion of the main leaf. Unfortunately, the overload has one major drawback: it limits spring compression vs the same pack with no overload, and thus limits overall articulation. Like everything in life, it's a tradeoff. I personally chose to incorporate the overloads in the 56" packs I am installing in my truck, since it's not a hardcore wheeler and the benefits outweigh the disadvantages. I ran them on the 52's I used to have on the rear, and they never seemed to really limit what I was able to do. They DID keep me from over-compressing and fatiguing the springs, so I am able to use them on the front of my truck to replace the 48" springs.

 

[speedy]

Here's a better picture of what Max was trying to show you

Stock H3 springs

For what it is the H3 has a overload:giggle:

 

[06 H3]

Is it safe to say that these springs are a reason for wheel hop on steep climbs? The very soft front suspension unloads on a steep slope then puts all the weight on the rear end and then the rear springs cant handle that weight and causes bouncing

 

[silvrzuki77]

Is there a difference in h3 verus h3t rear springs in payload? I assume there is but knowing chevy im not soo sure. Im looking at build a teardrop for offroad and was thinking of getting springs to match the truck for worst case spare parts. Anyone happen to know the capacity of each spring?

 

[Bigunit]

Is there a difference in h3 verus h3t rear springs in payload? I assume there is but knowing chevy im not soo sure. Im looking at build a teardrop for offroad and was thinking of getting springs to match the truck for worst case spare parts. Anyone happen to know the capacity of each spring?

The capacity of each spring on both the H3 & H3T is 1,600 lbs.

 

[MaxPF]

Here's a better picture of what Max was trying to show you

Stock H3 springs

For what it is the H3 has a overload:giggle:

Damn! It looked so feeble and thin that I thought it was a fifth leaf! :giggle:

 

[silvrzuki77]

Thanks bigunit!

 

[Sierra H3]

Having been playing around with my springs for awhile now...I think the SOA mod amplifies this leaf spring problem. I'm not sure why. After all, it seems logical that the springs are in the same situation whether the load is over or under the spring pack. Its the same load...concentrated in the same spot on the spring pack...in the same direction. Still, the springs seems to be more sensitive to vehicle weight with the SOA. There's probably some deeper engineering missing from my simple viewpoint but, that's what I've noticed.

Speedy's mod makes a lot of sense because he added beef to the "initial" spring, and not to the "overload" portion of the spring pack. This is a stark contrast to the traditional add-a-leaf which adds beef to the "overload" part of the spring pack, and does very little until the spring gets compressed. Unlike most trucks, the H3's problem is entirely with the main-spring problem...and its very obvious in the initial (static) position. So I'm hittin the bone-yards this weekend...looking for a 3/4T donor!

I think we off-roaders might be under-estimating the effect of two very common mods that most of us have down: (1) How much extra weight a larger spare adds, and (2) How much extra weight gets transferred to the rear suspension after a T-bar crank. I used to think that all of us H3 guys were complaining about "saggy" rear springs but, I'm started to re-think this problem. I don't think my springs are saggy. I just think their is too much weight on them. I say this because I just installed some brand new GM springs, and they look identical to my 15K mile springs (that I thought were worn-out). I have a heavy THORparts bumper, a heavy spare, some tools, and a nose lift...all of which seems to be simply too much weight for the stock rear springs. Even brand new ones! I have not removed all this stuff to verify for sure...but I'm 99% convinced. BTW...Has anyone actually restored their H3 to a desired ride height with nothing more than installing new GM springs? It didn't work for me.

This is a wild guess just from looking at others photos. So, feel free to shoot it down. But, the couple of more recent SOAs that I looked at had used shorter front hangers to improve ground clearance and limit the height of the rear lift. But, on the 2009 Moab concept, GM used the stock front hangers. The Moab concept didn't seem to have as much of an issue with rear sag - at least from the show photos. Changing the front hangers may have shifted some weight distribution to the rear, putting more longitudinal stress on the spring pack which in turn might lengthen it. Longer spring pack = more sag?

 

[Hunner]

Did you find a shot somewhere of that Moab Edition showing the front hangers and suspension? I would like to see it. All I can find is one beauty shot.
I recall an article that was a little vague about some of that.

 

[Sierra H3]

Did you find a shot somewhere of that Moab Edition showing the front hangers and suspension? I would like to see it. All I can find is one beauty shot.
I recall an article that was a little vague about some of that.

I am looking at the shots in Bebe's thread: http://www.hummer4x4offroad.com/forum/showthread.php?2605-Bebe-s-H3-Spring-Over-Tech

 

[Hunner]

I believe that white one that was in Moab now owned by an individual as I understand it, and may have worked for GM used stock hangers but drastically cut down.
The Moab edition concept as far as I know was never shown so that those were visible. That was why I was asking because I wanted to see what they did on the one they had produced.
All I found of the suspension was from the rear. I was just wanting to see what we could find.

http://www.hummerguy.net/hummer-news/hummer-h3-moab-sema-2009-photo-gallery

http://www.google.com/search?q=humm...BGsOC2AW5wLWCAg&ved=0CFkQsAQ&biw=1163&bih=577

 

[Sierra H3]

Thanks for the response Hunner. I went back in the garage and took another look to compare. Yep, the "White One" is missing the notch seen at the start of the stock spring hanger - cut down quite a bit. So much for that theory. But still, from the rear shots of those trucks, they don't seem to have the sag issue. Did GM make some additional adjustment? :huh:

 

[Hunner]

They may not have the weight some of us carry or the miles on those mules.
My rig decked out for long trips is just shy of gross, uh capacity GVWR, lol
I will have to address that at some point. I noticed on my last long trip even without all the recovery gear, tools and spares, pulling the boat mine is starting to sit lower.
I hope to run by the spring shop tomorrow since I will be over that way looking at tires and give them my ideas and see what they say.
Many years ago they re-arched the front and rear springs on my LandCrusher and I never had them sag again while I had it. Got enough arch to lift it and was very pleased with the ride on and off road.
I raised it just enough to fit 11/15 Tru-Trac tires, some of the first flotation tires available.
They did our Bobtrucks and trailer trucks that we haul grain in and that always worked even loading them to the max.
Probably posted this before but might not still be around, I loved that old Bus. We called it "ThuBus"