Bouncy ride after shock upgrade - do I need new springs??

[rschmitt]

Hi there,

our 2002 4runner is quite loaded (winch, bumper, RTT, armor), totaling around 550 pounds all the time, and then more when ready for trips, easily another 500-700 pounds. Now the ride has become super bouncy, and I am looking for remedies.

Until recently I ran "normal" Bilstein 5100 in the rear (for 0 - 2 inch lift), with OME 2895 springs. One of the shocks blew and I replaced them with 5100 for 1.5-3 inch lift.

Before replacing the shocks (even when one was leaking) the ride was ok (stiff but in a good way). Now it has become super bouncy. Everytime I go over a speed bump the rear end bounces up and down several times. I also have airbags and when I inflate them it gets better, but there is still a certain bouncyness.

I am wondering if I should probably get heavier-duty springs or if you have any suggestions.

For springs, I talked to a number of shops and they recommended.
OME 906

OME 2890

Dobbinson C59-297V


I'd be wanting to keep a similar lift (around 2-2.5 inches). Driven in the city but sees a good amount of dirt.


Cheers and thanks for your thoughts.

RS

 

[2TH4IST]

Too bouncy as in like there are no rear shocks? Or bouncy due to over dampened shocks or sitting on the bump stops?

Shocks control the bouncyness. If there is to much weight or too stiff a spring where it over powers the dampening in the shock you'll get bouncyness.

I don't know if you'll find a off the shelf solution for that much weight. You'll probably need to go with a custom valved rear shock either from radflo (they offer tuning when they build the shock), king (pay to get revalved), fox (pay to get revalved) etc.

Hope this helps a bit. I'm sure others will chim in to.

 

[phattyduck]

Until recently I ran "normal" Bilstein 5100 in the rear (for 0 - 2 inch lift), with OME 2895 springs. One of the shocks blew and I replaced them with 5100 for 1.5-3 inch lift.

If those are the rear Tundra shocks (check the part number...), then they will be too soft/underdamped. Leaf springs are partially self-dampening, so shocks made for leaf spring applications are generally lightly valved. If you need longer shocks (and have bump stop extensions to match), you can get 4th/5th/FJ rear shocks instead...

-Charlie

 

[alumarine]

If it wasn't bouncy with the old shocks but is with the new shocks then it's a new shock problem.
Go back to the same shocks that you had before if you liked the ride with them.
Springs aren't the problem.

 

[rschmitt]

Hi folks, thanks for chiming in.
Firstly, it's bouncy as in "no shocks," NOT bumpy as in "I am hitting the bumpstop," i.e., there is some oscillation (going up and down) after I hit a bump.

After looking at your replies, it seems to make sense that the shocks are the problem, as the problem occurred only after I put in new shocks.

Actually, simple as they are, the original Bilstein's were doing fine, even a bit on the firm side.
[MENTION=139000]phattyduck[/MENTION]. I do not think I need extended shocks, I just ordered those extended length shocks on a whim.

Kings or RadFlo's would be a dream but I am not sure if I can justify spending $1200 (+tax) on those. I might just go back to normal Bilstein 5100?!

As an intermediate solution, I found something like this: 60028 OME Rear Shocks, Firm Valving I'd give SRQ a call for sure, but anyone has experience with those shocks? couldn't find too much info online.

 

[2TH4IST]

Don't know anything about the ome firm valving. Don't give up on radflos/kings the rears are substantially cheaper then the fronts. Heck I got my radflo 2.0" 10" travel w resis for just a tad over 700 on sale.

They are currently back at radflo to get revalved, had the same issue as you did, damn near no dampening. But they are fixing it.

 

[phattyduck]

I'm having trouble believing you are only at 2-2.5" lift with OME 2895 springs on a 3rd gen (those are 2" lift with load for a 4th/5th gen). I would expect you are more like 3" lift, maybe more. Measure from the hub center to the fender lip - 20" is considered "stock height" for reference (despite the fact that stock height did change through the years).

Most have reported that the "firm" OME valving is pretty stiff. I have been happy with my 5100's for a few years. If they worked for you before, a new set is cheap... Just make sure you get the 4Runner specific ones - assuming you aren't lifted too much.

-Charlie

 

[rschmitt]

Hi thanks to all who chimed in here!!!

I finally had the time to install "normal" Bilstein5100 for the 3rd gen 4 runner. Now the ride quality is back to being really nice. With our rooftop tent etc. the stiffness is perfect and the ride is well balanced.


After checking the part numbers, I can indeed confirm that the "Extended travel" 5100s for the 3rd Gen are the same as the Tundra shocks. With the OME springs those were a terrible combination.

Not only a lot of rebound, but also the springs got lose when flexing/unloading (e.g. after going over a speedbump).

For the price, I will probably stick with the Bilstein 5100 for now might go for something better later.