I was under my truck investigating an unrelated leak and saw this curious looking thing. Nothing's wrong with it I was just curious as to what it is. Its behind my gas tank up under the bed right next to the shock on the drivers side. Here is a bad quality pic, my phone was all I had on me!

 

Its kinda hard to tell from the photo but it looks like the brake adjustment valve. It adjust the brake line pressure to the rear wheels based on the load in the back. (hence the rod that runs from the frame to the axle used to determine load)

 

That's a thermoweevil valve. Regulates how much food the squirrels under the hood get...

Seriously....I don't know.

 

The picture is to grainy to tell..

What connects into it-any lines-brakes?

 

ive heard of that part before...

 

Toyota did away with the Thermoweevil valve in the late 80s instead going with the Kanueturvalve which feeds hamsters. Hamsters eat less. I think its an emissions thing

 

Now THAT'S funny!

David: I went out and looked at my axle.. I think Mike's on the money. At least from what I can tell, it looks like that's exactly what that would do...

 

Hard to tell from the pic but it looks like the LSPV (load sensing proportioning valve) to me.

 

Yep, that is the LSPV-BV:
http://www.4crawler.com/4x4/4R_suspe...ortioningValve