So I bought a set of used OME 906 rear coils to help support my upcoming rear bumper w/ tire carrier install. Date on the box said 5/2017, so I'm assuming on the conservative side the PO had them for 2.5 years.
My goal is to keep the stock 99 height and utilize the existing parts (Trekmasters and 32" Bridgestone Revo 3's) while not sagging. Searching around, here's the coils I was considering with spring rates:
• 890 - Approximately 2-2.5" Lift - Medium Load - Stock Weight
• 906 - Approximately 2" Lift - Heavy Load (330 lbs -GVW)
• 891 - Approximately 2-2.5" Lift - Heavy Load (Constant 660 Lbs -GVW)
I ended up going w/ the 906's because of the smaller lift and the moderate spring rate.
So I removed my old 99 rear coils (which by the way, are so comfy now b/c they're so nicely worn in) and installed the 906s. Vs. factory fresh specs, here's my measurements from hub center to the little bolt that secures at the apex of the bottom side of the wheel well arch (SR5 style textured black fender flares):
OLD VS NEW (Separated by pipe)
Rear driver's side (99 coils): 21.5" | Used 906: 23.0"
Rear passenger side (99 coils): 21.5" | Used 906: 23.0"
So assuming my measurements are correct the rears sagged 0.5" from factory new spec, which is acceptable I guess for 2 year old springs. Hopefully no more sagging beyond this, but I do have Airlift bags inside the coils too.
Before and after pics attached. It should be pretty obvious, but the day time pic is with the 99 rear coils and the night time gas station pic is with the used OME 906 coils.
The OME 906 coils definitely ride a bit stiffer, but not harsh by any means.
I'll let you guys know how they work with the bumper and tire carrier.