SparksLex

Hey guys,

I'm trying to find out the most practical way to buy a service manual (read: Not willing to fork over $600 on ebay), and searching this forum for a bit hasn't been that effective, so real quick, what kind of rear suspension would a 2006 IS350 have? Live rear axel? Independent?

Thanks, in advance.

An2ny

If you have an IS250/350, you can just look at it...You do not need a service manual.
Front: Double Wishbone
Rear: Multi-Link

What info are you looking for?

SparksLex

Haha, what a great response. I guess I thought it'd be too convoluted underneath to figure it out.

I'm just looking for general information about the car. I'm going through this book reading about different suspension systems and I just wanted to identify what my car has and how that system functions versus others. I have very little knowledge of the parts and how they work together so thats where I'm at.

When you say the rear is just multi-link, my book breaks that down into a double wishbone, trailing link, or a trapezoidal link. And all of this is just considered "Independent Suspension", according to my book.

Gville350

iTrader: (10)

^It definitely has independent rear suspension. The multi-link, in this case, means there are various "arms" connected to the rear hub to keep it stable. You've got the rear LCA (lower control arm), toe arm, camber arm, and another one that escapes me (traction arm?). Of course you've got the rear sway attached to the LCA and the shock too. Because the 2IS is RWD (rear wheel drive) of course you've got the drivetrain connected to them as well via the half-shafts from the factory open differential.

SparksLex

So is multi-link basically a catch all for this sort of independent suspension that has too many parts to list, basically? Like a double wishbone suspension is called that because it basically has double wishbones, but it would be silly to name all of the parts of a multi-link suspension, so its just referred to as multi-link."

Gville350

iTrader: (10)

It's not a catch-all; it's a specific type of suspension. Here's a visual of the 2014 rear suspension, which is very similar to the 2IS :

SparksLex

Wow, cool. Iit looks like its all held together by a thick rectangular... "web" piece of metal? Would that be a sub-frame?

Gville350

iTrader: (10)

Yes.

Here is what the 2IS rear subframe looks like (upside-down) without everything attached to it :

SparksLex

Cool.

Is the point of a sub-frame to just have something that can be easily attached/removed/fixed instead of just one large frame?

Gville350

iTrader: (10)

Subframe, per WIki : http://en.wikipedia.org/wiki/Subframe

An2ny

Nice Pic!
OP- This is froma 2014 IS; the 2gen has Coilovers front and rear.

SparksLex

Why switch to spring and shocks?

Gville350

iTrader: (10)

I sure there's a good reason; obviously since the 3IS out-handles the 2IS, it's a move in the right direction.

SparksLex

I was thinking that maybe one form is better than another, but I guess you're just at the mercy of your engineers, whats the best at the current time and what fits within the boundaries of the platform you're creating.

In the back of my mind, I thought McPherson systems were more advanced than shock and coil spring systems. I guess not.

Gville350

iTrader: (10)

It's solely based on the chassis really, and of course the engineers did make it that way for a reason. The 3IS's handling is superior because of all the factors coming together making the best handling pkg Lexus has seen in a "family sedan."