New Eibach "HD" Rear Springs

I have the decked system and probably ~300lbs at all time in the setup. It almost seems like there is a bit of reverse rake now. I wonder if getting the HD springs for the rear only will get it more level or even a slight bit of rake? Any difference in the ride quality? I am on factory with everything else. I am also considering a diamond back HD cover.
Ride quality is pretty unchanged for me other than it isn't as bouncy with the weight. I haven't done a recalibration yet, and I'm not entirely sure I need to. The truck seems to perform just fine without it. I've jumped it a little bit here and there and done a lot of trails with some big rocks and haven't had any issues yet.
 
Oh for sure.

I was going to email Eibach and see if they could send me a free length measurement to compare mine to, that way I could periodically check for permanent sag. I may also trim my front springs or go back to OEM in the front to get a slight bit of rake back. I want to install a rack on my camper shell but it's just too much weight at the moment.

I may also follow your lead and add the spacers to the rear.
Eibach customer service is on top of it, I got an answer same day. Here's what they said:

"The free length measurement, 24.33", is just a reference measurement and is not an indication of total lift amount. Free length will change depending on the spring rate tolerance. The pic you sent is at an angle, so the perspective will have some affect on the stance of the truck."

So if anyone wants to pull the spring and check it, 24.33 is the free length you should compare to. If it's less than that, the spring has been permanently deformed and it's probably a warranty replacement situation. I'll check mine at some point, though it isn't a massive priority for me at the moment.
 
I just bought these from 797 Performance and here are measurements from stock to Eibach 1.6/1.5 springs and Carbon Shocks and Eibach HD rear springs.

They are the same length as the non-hd Eibach springs and there is no change in ride quality.
20251114_164155.webp


TRX - stock springs
RR 40(with 250lbs) - 42.5(stock)
LR 40(with 250lbs) - 41.5(stock)
RF 39.5
LF 39

TRX - Eibach springs (with 250lbs)
RR 41 3/4
LR 41 1/2
RF 40 1/2
LF 40 1/4

Carbons and HD Eibach (with 250lbs)
RR 43
LR 42 3/4
RF 41 1/2
LF 41 1/4
 
ESM, thanks for the measurements! This is really helpful.

Also big BUMP to Nick797 and 797 Performance. Pulled the trigger and ordered 1.6" Eibach front and HD Eibach Rears over New Years... they showed up on the 4th!!! Now that is awesome service!
 
ESM, thanks for the measurements! This is really helpful.

Also big BUMP to Nick797 and 797 Performance. Pulled the trigger and ordered 1.6" Eibach front and HD Eibach Rears over New Years... they showed up on the 4th!!! Now that is awesome service!
Anytime!
 
I want to thank/big bump to ESM, DubStep Shep, FULLTHROTTLERICK, and Nick797 @ 797 Performance for all the great info and insights, as well as all others who posted on this and other Eibach threads. HUGE help, greatly appreciated.

Pulled the trigger on an Eibach Spring upgrade/lift for my 2023 TRX Lunar and could not be happier. Provided an immediate and NOTICEABLE driving improvement over stock springs...IMHO it is now much flatter in corners (less body roll), much improved "point and stick" vs. "turn and pray" cornering at speed, significantly less nose dive with hard braking, and I like what I will call a more "sportier" ride. Sucks up the bumps, seems to let the Bilsteins do their job, and rides smoothly and solidly (less floaty ride). Just confirms all the things others have stated. Hope it does not "settle" much and retains all these great traits over time.

Note: my design goal was to zero in on a more "Overland Operator" target vs. "Baja Beast". I also like a little R2F rake vs. level (1" was my goal) at normal loadout. Also, all road testing so far has been on road... still need to get out on some trails to test off-road feel.

My config:
- 1.6" Eibach Pro FRONT
- 2.6" Eibach HD REAR
- Foutz TRX Adjustable Panhard Bar (Johnny Joint)
- 1.25" BORA spacers F+R*
- OEM stock 18" beadlock capable wheel (I really like the look of these)
- Nitto 37x12.5 Recon Grappler tires

*Honestly I would have liked a little more tire poke than what the 1.25" BORAs provided... I will likely replace with 1.5" at some point. If anyone is interested in buying a full set of new 1.25 BORA spacers PM me... might accelerate my swap to 1.5" :)

End result over OEM (note tires and wheels were unchanged from OEM config to new Eibach/BORA setup):

TRX - OEM Springs / No BORA spacers
DR (with 290lbs**) - 42"
PR (with 290bs**) - 41.75
DF 40.5
PF 40.5
Rake: ~1.5"
Loadout** = full tank + 290lb (Rambar, RetraxPro XR, Billie Bar 6")

TRX - Eibach 1.6" PRO Front + Eibach HD 2.6" Rear + 1.25" BORA Spacers
DR (Approx 390lbs) - 44
PR (with 390lbs) - 43.75/44
DF 42
PF 42
Loadout** = full tank + 390lb (Rambar, RetraxPro XR, Billie Bar 6", BW Tow and Stow hitch, Old OEM springs and panhard bar in bed)
Rake: ~2". Expecting as I remove the old OEM springs and panhard from the bed, add an ARB baserack, ROAM cases, and maybe a Decked CargoGlide, I should get to target 1"-1.5" rake. While with full gear loadout = level.

Other notes:
- No issues getting 4wheel alignment. Running great and true
- 1.25" spacers + OEM beadlock required NO lug trimming (extra lug length fits fine in OEM wheel pockets)
- No fender liner trimming needed, No rubbing on flat level ground at full lock, both forward and reverse. HOWEVER, I am chasing an intermittent, slight rub rolling downhill and turning full lock Right into a parking space (expect I will also see this with full Left turn lock down hill). Assume this is due to front suspension load and spring compression downhill. Bottom line... it is very tight in there up front. I am expecting to have to do some front fender liner trimming with any pivot to wider 1.5" spacers.

Hope this helps others looking to do the same/similar.
 
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Glad it worked out for you! I have some brand new Foutz 3/4 spacers that I didn't use because I went with the HD springs instead. If you find that you need more height after you install all of your gear, I'll ship them to you for free if you just pay for shipping.
 
Glad it worked out for you! I have some brand new Foutz 3/4 spacers that I didn't use because I went with the HD springs instead. If you find that you need more height after you install all of your gear, I'll ship them to you for free if you just pay for shipping.
Hey thanks again, and appreciate the Foutz spacer offer. Will let you know...
 

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