Rear spring recommendation

[afgman786]

I was in a similar situation deciding on springs after ordering a rear bumper. I ended up going to 2724s. Rear dual swingout by Trail Tailor, homemade platform in the rear and tool bag underneath that platform. When I was loaded up for my past trip after installing bumper and springs it was perfect spring rate. Unloaded I've got rake back which is nice, but it is a little too much spring. Not jarring like a 1ton though. If you go with helper bags the 23s would be the perfect option from my experience on 24s.

The 21s will be too light of a spring for a rear bumper and trailer. I had trim packers in the rear to give rake to the 21s and would need a weight distribution to level the truck back out with my trailer.

Also the easiest way I've learned for removing passenger springs in taking the top nut off of the sway bar end link on passenger side and having it drop down. Picture to help explain what I meant.

 

[linuxgod]

I was in a similar situation deciding on springs after ordering a rear bumper. I ended up going to 2724s. Rear dual swingout by Trail Tailor, homemade platform in the rear and tool bag underneath that platform. When I was loaded up for my past trip after installing bumper and springs it was perfect spring rate. Unloaded I've got rake back which is nice, but it is a little too much spring. Not jarring like a 1ton though. If you go with helper bags the 23s would be the perfect option from my experience on 24s.

The 21s will be too light of a spring for a rear bumper and trailer. I had trim packers in the rear to give rake to the 21s and would need a weight distribution to level the truck back out with my trailer.

Also the easiest way I've learned for removing passenger springs in taking the top nut off of the sway bar end link on passenger side and having it drop down. Picture to help explain what I meant.
View attachment 3010041

Nice, thanks. I ordered the IronMan 220-880 springs which look comparable to the 2723. We'll see how it plays out... feels like it's the right call at least.

And thanks for the tip on the passenger's side spring, I had disconnected the sway bar at the axle and it's a PITFA to get realigned correctly. That PS spring was tough for me to get in and out, especially since the Tough Dog spring is like an inch longer than most other versions. Someone else previously mentioned disconnecting the panhard rod as well, which is something I hadn't done. Did you do that?

 

[afgman786]

Nice, thanks. I ordered the IronMan 220-880 springs which look comparable to the 2723. We'll see how it plays out... feels like it's the right call at least.

And thanks for the tip on the passenger's side spring, I had disconnected the sway bar at the axle and it's a PITFA to get realigned correctly. That PS spring was tough for me to get in and out, especially since the Tough Dog spring is like an inch longer than most other versions. Someone else previously mentioned disconnecting the panhard rod as well, which is something I hadn't done. Did you do that?

I only do the end link on the passenger side and has worked well for me. First time I did it was to add 30mm of trim packers in the rear to give me rake with the 21s, then did it again the other month to swap in the 24s. After undoing the nut for the frame mount end link I use my foot to press down on the axle at my spacers and can get the springs in and out. I didn't think the panhard would help too much since the sway bar would still be limiting how much the passenger side can drop.

I also only do 1 side at a time, meaning undoing one shock swap spring, rebolt shock, repeat on other side. Not sure if that's how the people undoing the panhard do it?

 

[linuxgod]

I only do the end link on the passenger side and has worked well for me. First time I did it was to add 30mm of trim packers in the rear to give me rake with the 21s, then did it again the other month to swap in the 24s. After undoing the nut for the frame mount end link I use my foot to press down on the axle at my spacers and can get the springs in and out. I didn't think the panhard would help too much since the sway bar would still be limiting how much the passenger side can drop.

I also only do 1 side at a time, meaning undoing one shock swap spring, rebolt shock, repeat on other side. Not sure if that's how the people undoing the panhard do it?

Actually doing one side at a time sounds like a nitfy idea I might have to try. Do you lift the who rear end when you did it or just one side? I'd done both sides simultaneously previously since I was jacking the whole rear end up onto stands.

I'm assuming you opened the KDSS screws as well when you did this? (just checking... thinking if you didn't that KDSS might actually help force the one corner open as the other 3 sides are compressed...

 

[montegofd3s]

I was in a similar situation deciding on springs after ordering a rear bumper. I ended up going to 2724s. Rear dual swingout by Trail Tailor, homemade platform in the rear and tool bag underneath that platform. When I was loaded up for my past trip after installing bumper and springs it was perfect spring rate. Unloaded I've got rake back which is nice, but it is a little too much spring. Not jarring like a 1ton though. If you go with helper bags the 23s would be the perfect option from my experience on 24s.

The 21s will be too light of a spring for a rear bumper and trailer. I had trim packers in the rear to give rake to the 21s and would need a weight distribution to level the truck back out with my trailer.

Also the easiest way I've learned for removing passenger springs in taking the top nut off of the sway bar end link on passenger side and having it drop down. Picture to help explain what I meant.
View attachment 3010041

Curious where you got the sway bar mount?

 

[afgman786]

Actually doing one side at a time sounds like a nitfy idea I might have to try. Do you lift the who rear end when you did it or just one side? I'd done both sides simultaneously previously since I was jacking the whole rear end up onto stands.

I'm assuming you opened the KDSS screws as well when you did this? (just checking... thinking if you didn't that KDSS might actually help force the one corner open as the other 3 sides are compressed...

Yea I keep the whole rear end up on jack stands as well. This last time I did not open KDSS and went just as smooth as it did with KDSS open.

Curious where you got the sway bar mount?

That is just a random picture from Google. First picture that popped up that gave a visual for which part of the sway bar I was referring to.

 

[DJCloz]

I finally got around to installing my new Ironman rear coil heavies this eavening. Pretty straight forward. Took me about 45 min disconnecting lower shock mounts, losing the kdss valves 3 turns and disconnecting the right side sway bar mount. I also disconnected the pan hard bar and replaced it with a adjustable Ironman. I think I need to make a few tweaks there still to center the axle. It looks like I gained about 1.75-2" of lift in the rear. I took it for a quick test drive and it feels pretty good. A little more firm, but not harsh. I did notice less body roll when taking turns a little fast. I liked that. I need to throw my 3rd row back in and my drawer and fridge and see if it settles, but so far I'm happy! Now I'm thinking maybe I need stiffer front coils as well .

 

[TLC2013]

I finally got around to installing my new Ironman rear coil heavies this eavening. Pretty straight forward. Took me about 45 min disconnecting lower shock mounts, losing the kdss valves 3 turns and disconnecting the right side away bar mount. I also disconnected the panhard bar and replaced it with a adjustable Ironman. I think I need to make a few tweaks there still to center the axle. It looks like I gained about 1.75-2" of lift in the rear. I took it for a quick test drive and it feels pretty good. A little more firm, but not harsh. I did notice less body roll when taking turns a little fast. I liked that. I need to throw my 3rd row back in and my drawer and fridge and see if it settles, but so far I'm happy! Now I'm thinking maybe I need stiffer front coils as well .

View attachment 3012528

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View attachment 3012531

View attachment 3012532

Thanks for the update. I am leaning toward these springs as well. Debating between theSe Ironman springs or just adding spacers to gain some rake back with loaded up with gear.
I have the 3rd row removed and the Dissent rear bumper with tire carrier and accessory tray. I believe this is similar to your setup? Is the new measurement of approx 40 7/8”with or with out those spacers ?

 

[DJCloz]

Thanks for the update. I am leaning toward these springs as well. Debating between theSe Ironman springs or just adding spacers to gain some rake back with loaded up with gear.
I have the 3rd row removed and the Dissent rear bumper with tire carrier and accessory tray. I believe this is similar to your setup? Is the new measurement of approx 40 7/8”with or with out those spacers ?

The new measurement is without the spacers from ground to fender. Thats on a 35'' KO2 tire which technically measures @ 34.5'' tall. I do have the dissent rear bumper with duel swing outs, the fuel tray and the full sized 35'' tire back there. Hacking up those rear ironman coil spacers to fit the 200 was a real PITA. I had those laying around from a previous 80 build, but when I was looking a year ago finding 200 series rear coil spacers was really hard to find.

 

[TLC2013]

The new measurement is without the spacers from ground to fender. Thats on a 35'' KO2 tire which technically measures @ 34.5'' tall. I do have the dissent rear bumper with duel swing outs, the fuel tray and the full sized 35'' tire back there. Hacking up those rear ironman coil spacers to fit the 200 was a real PITA. I had those laying around from a previous 80 build, but when I was looking a year ago finding 200 series rear coil spacers was really hard to find.

Cool, good to know. I have 35” K02s on my 73’ Suburban (35x12.5x15 c rated) they barely measure 33.5” tall (measured vertically) when mounted on the truck. Are you also seeing a similar measurement?
Lol yeah I gave up trying get those Ironman 30mm spacers on the bump stops. I butchered them up so badly trying to make them fit. Ended up going with the OME 10mm spacers and will stack them.

 

[wingshooter8800]

Nice, thanks. I ordered the IronMan 220-880 springs which look comparable to the 2723. We'll see how it plays out... feels like it's the right call at least.

And thanks for the tip on the passenger's side spring, I had disconnected the sway bar at the axle and it's a PITFA to get realigned correctly. That PS spring was tough for me to get in and out, especially since the Tough Dog spring is like an inch longer than most other versions. Someone else previously mentioned disconnecting the panhard rod as well, which is something I hadn't done. Did you do that?

Interested in seeing how this works out for you. Dobinson 547 rear springs. They totally squat with my trailer tongue weight (with WD hitch and airbags).

 

[100kiwi]

Ok I've spent obscenely too much time on this. Bumper is painted and ready for installation this weekend. Pre-bumper I have the Tough Dog TDC931L springs and when I'm loaded with family and cooler I sit very level (no rake), or a bit of squat if I have the trailer hooked up... measurements below from top lip of my 17" Icon wheels to the fender (I used that instead of the center hub because it's hard to determine the precise center):

Setup	LF	RF	LR	RR
Vehicle only, airbags at 5psi	12	12.5	13.5	14
Trailer hitched, no weight dist.	13	13	11.5	12.25
Trailer hitched, WD set	12.75	12.5	12.25	12.75
Trailer hitched, WD set, 30 psi	12.75	12.5	13	13.25

I've got about 1.5" of rake when empty right now. I'm running about 1" of squat when trailered but otherwise unladen with no family or camping gear (1/2"-3/4" too high in the front, 1/2"-3/4" too low in the rear). Laden with family and dog and it's another 300# in the rear. And I haven't yet added 200# of bumper plus all the leverage associated with crap hanging off the rear. Thus even without have actually installed it yet (hoping to do it this weekend) I'm pretty damn sure I will need to step up the rear springs. That said, without the trailer but with an extra 300# in the trunk (kid + dog) the ride is spot on plush and perfect right now.

I charted all the rear spring options I could find that would be relevant. Info below is what the vendors claim. My setup is in green. Options I'm currently considering are in orange. It's interesting to me how some of the numbers line up but others don't. For instance the heights, coil wraps, wire diameter, and #/in ratings between the King KTRR-131HHD and OME2723 are nearly identical, but the King spring is rated for 100kg more constant load. They also look similar to the Tough Dog TDC931VHL spring but that has a minimum constant load rating at the top of the King and OME max range - and that plus my current experience with the basic Tough Dog spring makes me think the constant load ratings somehow matter more than the free height, wire diameter, and compression specs. OME and IronMan spring options are half the cost of the Tough Dog and King options in the USA... otherwise I'd likely just step up to the next TD spring.

vendor	part #	l/h mm	r/h mm	coils	wire mm	low lb/in	high lb/in	min load kg	max constant kg	min load lb	max const lb
King Springs	KTRR-131H	450​	470​	7.2​	18​	240​		100​	250​	220​	550​
King Springs	KTRR-131HD	430​	450​	7.2​	19​	275​		100​	300​	220​	660​
King Springs	KTRR-131HHD	430​	450​	7.2​	20​	340​		300​	500​	660​	1100​
King Springs	KTPR-131HD	435​	455​	8.4​	19​	250​	350​	100​	300​	220​	660​
OME	OME-2721 0" lift	430​	440​	8.42​	18.5​	270​	350​	0​		0​
OME	OME-2722 1" lift	430​	440​	7.2​	19​	275​		0​	200​	0​	440​
OME	OME-2723 1" lift	440​	450​	7.2​	20​	340​		200​	400​	440​	880​
OME	OME-2724 1" lift	435​	445​	7.2​	21​	400​		400​	600​	880​	1320​
OME	OME-2725 1" lift	435​	445​	7.71​	22​	440​		600​		1320​
Tough Dog	TDC931L 1" lift	445​	475​	7.2​	18​	240​		0​	300​	0​	660​
Tough Dog	TDC931HL 1" lift	425​	455​	7.2​	19​	275​		300​	500​	660​	1100​
Tough Dog	TDC931VHL 1" lift	425​	455​	7.2​	20​	340​		500​		1100​
Bilstein	B12 53-297686							180​		396​
Eibach	E30-82-072-04-02					250?		90​	180​	198​	396​
Icon	Dual Rate 52750					?	?			0​	0​
Trail Tailor	Tourflex Standard	505​	515​	9.77​				100​	300​	220​	660​
Trail Tailor	Tourflex HD	545​	555​		19.5​	180​	320​	300​		660​
Ironman	TOY064A 1" lift	425​	440​		19​	269​		0​	200​	0​	440​
Ironman	TOY064B 2" lift	455​	470​		19​	269​		0​	300​	0​	660​
Ironman	TOY064EA 2" lift	465​	475​		20​	286​		100​	400​	220​	880​
Ironman	TOY064C 2" lift	455​	465​		21​	371​		400​		880​

I found out the Eibach HD spring specs.
300lb/in.
Height, 414mm, no difference left to right.

 

[linuxgod]

I found out the Eibach HD spring specs.
300lb/in.
Height, 414mm, no difference left to right.

Thanks, table updated

 

[100kiwi]

Thanks, table updated

Thank you for the table. Great to have all that info in one place.
I have been on OME 2721 springs, and just ordered 2723s as I have added a karmar rear bumper. I'll post results once I install.

 

[100kiwi]

I got the 2723s installed. It added about 1.3 inches of lift back to the rear. Ground to fender is now 39 inches. (Tires 275/70/18)
With the 2721s it was almost level, a very small rake, and needed air bags to hold it with RTT.
I don't notice any ride quality change.

 

[montegofd3s]

I got the 2723s installed. It added about 1.3 inches of lift back to the rear. Ground to fender is now 39 inches. (Tires 275/70/18)
With the 2721s it was almost level, a very small rake, and needed air bags to hold it with RTT.
I don't notice any ride quality change.
View attachment 3031307

Truck looks great. What shocks are you running?

 

[100kiwi]

Truck looks great. What shocks are you running?

BP-51

 

[TLC2013]

@linuxgod nice work putting the table together, thank you ! It’s a Great resource that led me to install the Ironman medium springs (TOY064EA 2" lift) 220-880 lbs. They ride fantastic, a little firmer then the Tough Dogs, and eliminated a side to side wiggle when going over bumps and turning. They added the rake I was looking for, maybe too much, but they hopefully will settle a bit after some miles.
@DJCloz have yours settled a bit after some use ?

Here are my before and after hub to fender measurements (w/ LT275/70r18 Kenda Klever RT)

Tough Dog
RD-38”
RP-38 1/5”

Ironman
RD-39 1/8"
RP-39 1/2"

 

[dcs111]

@linuxgod nice work putting the table together, thank you ! It’s a Great resource that led me to install the Ironman medium springs (TOY064EA 2" lift) 220-880 lbs. They ride fantastic, a little firmer then the Tough Dogs, and eliminated a side to side wiggle when going over bumps and turning. They added the rake I was looking for, maybe too much, but they hopefully will settle a bit after some miles.
@DJCloz have yours settled a bit after some use ?

Here are my before and after hub to fender measurements (w/ LT275/70r18 Kenda Klever RT)

Tough Dog
RD-38”
RP-38 1/5”

Ironman
RD-39 1/8"
RP-39 1/2"

View attachment 3038424

View attachment 3038425

View attachment 3038426

That truck is made/ modded for war! Nice work

 

[DJCloz]

@TLC2013 I added a spare, spare in the rear to add some weight. My measurements now are about 41.5" to ground, 24.5 center hub to fender. Maybe it settled 1/4"??