Lumps of Steel In Front of the Rear Bumper?

[ricker]

My 2010 LR4 has a rather large (about the size of a fat brick) lump of what appears to be steel on both side of each frame rail just in front of the rear bumper. They appear to be connected though the frame rail in a way that allows them to pivot front to rear. They can swing to the rear about 5 degrees until they hit the back of the rear bumper and they can swing forward about 20 degrees until something on top hits what is probably the back of the bumper.

Can anyone please tell me what these are and their function?

Thanks, David

 

[Rover7777]

I think they are called load leveling dampers....using my bad memory though-)

 

[jjvd21]

Think they are referred to as "harmonic dampeners" or something like that:

YouTube - Rear weight

 

[ricker]

Hi jjvd21,

That is exactly what I am talking about except that my LR4 has a pair on each frame rail. It does not seem like a very good design. When they swing to the rear they whack the back of the bumper. I would not think that this would be good for the bumper over time. You think they would have had a stop or something to keep it from hitting anything.

I am going to have the oil changed in a couple of weeks (at 7500 miles) and will probably ask the dealer to confirm that these are supposed to be the way they are.

Thanks again,

David

 

[blackforestham]

Don't trip. There are what they are - harmonic dampeners. They are designed to offset common resonant or droning conditions from road noise, vibrations, oscillations and crying children. Personally, I don't get it but some propeller head engineer says it works. I'm just scared my rig would self destruct if they were removed. Think of them as high end truck nuts.

 

[Neild]

We;;, you've been told the LR3 is the Dogs ********, now its actually got them to prove it!!

 

[tjp74]

Adding a mass to control the unwanted resonance is nothing new. Many cars and trucks have those especially around exhaust pipe hangers to control the exhaust vibration.