2007 4Runner SR5 4WD, 160k miles
Just had new shocks and springs put on this week after the original shocks were leaking. I did have a Cornfed 2/1 spacer kit on it originally as well which was installed when I first bought it new.
Shocks: Bilstein 5100 on 0" perch
Front Springs: Old Man Emu 2884 (590-lb / 15.3" Length 1.7")
Back Springs: Bilstein 36-281817 (1.0")
On pavement the new setup feels good (about as stiff as before with the spacer lift) but on concrete roads I'm bouncing up and down like an unloaded trailer. It's happening rhythmically between 40 and 65 mph, which of course is the speed of traffic on my main commute. I'm not sure if it's the shocks, springs, or combination of both that happen to be perfectly in sync with the spacing of the control joints. Almost feels like I need a mouth guard to drive on it.
Questions:
- Could this be an installation issue?
- Is this more likely to be the shocks, the springs, or the combination?
- If it's the shocks, can I install new Toyota shocks and keep the current springs (can they handle the lifted springs)?
- Any hope this will calm down with time as the springs settle? (It's still lifted more than 1.7"/1").