Suspension and body movement question

[oryades]

Hi everyone. I am in the pursuit to find the sources of noise while driving and recorded a video of the rear suspension and body/frame movement. The camera is mounted on the body bushing bolt. My rear coils are worn out, and are due for replacement, hence I hit bump stops very frequently.

So the question is how bad is the relative movement of body against frame?

 

[RedSled]

Holy crap man, do you seriously ride around like that?

 

[oryades]

Which part do you mean? [emoji15]
Hitting bump stops or body movement against frame?

 

[JohnMc]

I really have no frame of reference in what is normal vs. what isn't - that's certainly a new viewpoint for me.

But the frame is intended to flex a *'fair' amount vs. the body, which isn't really supposed to flex much at all. That's why it has those fairly soft body mounts in all locations, and the brake lines have little flexy coiled sections between the body and frame. Is it good? Is it bad? Who knows, it's just how body-on-frame vehicles work - the frame isn't really a rigid solid structure, the body is more stiff than it is (although the body isn't encountering the same twisting forces).

I can say that on my 4Runner I replaced the stock rear bumper (which mounts to the body, oddly enough, not the frame) with a very solid, hefty 4XInnovations bumper with a rear mounted spare. This bumper bolts to the frame - which previously just had the trailer hitch bolted to it back there (the new bumper has a hitch built into it). Right off the bat I could see the spare wiggling and bouncing around a little through the rear window, when going over rough stuff. I thought this might be the bumper itself wiggling around at first, but after checking it out, it was the rear section of the frame that was doing the wiggling. I put some stiffer rear body mounts on and the bumper stopped wiggling around. It's a case of the body supporting the frame... but it works.

 

[Sean K.]

Hi everyone. I am in the pursuit to find the sources of noise while driving and recorded a video of the rear suspension and body/frame movement. The camera is mounted on the body bushing bolt. My rear coils are worn out, and are due for replacement, hence I hit bump stops very frequently.

So the question is how bad is the relative movement of body against frame?

VERY interesting video. I have nothing to add unfortunately as I don't know how much mine moves/flexes.

Could we be seeing an optical illusion and the body is moving on the bushings; not that the frame is moving that much? I dunno....sure looks like the frame is what's moving especially in relation to the tire/inner fenderwell (body).