rear suspension question

[jcb]

I have replaced all bushings and struts and the diff mount. This job is too hard to not get it right so...

I have read the FSM and all the posts I could find but am still not sure of the correct procedure to tighten the bolts for the transverse link brackets. Should I torque the vertical bolts to spec or just snug before putting the wheels on the ground. Also does the car need to be level when I torque the horizontal bolts. I need to put ramps under the rear wheels to gain access for the final tightening. I hope this post makes sense. Thanks for any and all advise. JB

[Zed Head]

Did you install aftermarket urethane bushings or factory rubber?

The reason that you tighten the factory rubber with a load on the wheels is because the rubber does not slide or rotate against the metal bracket very much, most of the suspension movement is taken up within the rubber itself. So the point of tightening with the wheels loaded is so that the rubber is not "loaded" or strained most of the time, only when the suspension moves.

The round urethane replacement bushings, on the other hand, rotate within the brackets when the suspension moves (typically causing noise, that's why grease is recommended). So they can be tightened at any time. They're just going to rotate in the bracket anyway.

That's my interpretation of the bushings options. I could be wrong.

[ernesto]

I know this is an old post but can anyone confirm Zed Heads opinion regarding the following?  Zed, do you still have the same opinion?

On 10/7/2013 at 12:05 AM, Zed Head said:

The round urethane replacement bushings, on the other hand, rotate within the brackets when the suspension moves (typically causing noise, that's why grease is recommended). So they can be tightened at any time. They're just going to rotate in the bracket anyway.

I just installed all new bushings (Energy Suspension) on the rear of my 280z, I did not have the weight on the wheels when I torqued the rear control arm. Is this a problem?

Also.........slightly different question:

I did not grease the outside of the rear inner control arm (transverse link) bushings. For some reason because they are sandwiched between the frame and diff mount front member (forward ones) and the mounting rear bracket (aft ones) I didn't consider it. Should I take the time to uninstall to grease them, Do they need it? (this is just the outside of the bushing. The inside is greased)

 

Thank you,

E

[Zed Head]

1 hour ago, ernesto said:

Zed, do you still have the same opinion?

Yes.

[EuroDat]

2 hours ago, ernesto said:

Also.........slightly different question:

I did not grease the outside of the rear inner control arm (transverse link) bushings. For some reason because they are sandwiched between the frame and diff mount front member (forward ones) and the mounting rear bracket (aft ones) I didn't consider it. Should I take the time to uninstall to grease them, Do they need it? (this is just the outside of the bushing. The inside is greased)

Thank you,

E

It should not be too much a problem. The outer circumference has more resistance area and no lube causing more resistance it's unlikly to turn. If you lubricated the inner contact surface then you should not has any issues.

[JTO]

I think Zed Head's thinking is correct (as it usually is). With the rubber bushings installed, I have tightened the control arm inner bushing bolts with the rear suspension hanging, then, after lowering the car and driving down the driveway, there was still considerable camber (vertical misalignment) in the rear wheels. You could try this process with the (lubricated) PU bushings and see if the rear wheels are vertical after lowering and driving the vehicle down the block. If the rear wheels straighten up, then the PU bushings are turning in the bushing brackets with the up and down movement of the control arm (assuming everything else is in order). In my experience, when using the rubber OEM bushings, you definitely have to lower the vehicle and put the load on the control arms before torqueing the bushing bolts.