New Trailing arm sounds like a bird
 

I just replaced my right rear trailing arm (aka tuning fork) with a TRW unit.
The clunk is gone but the new arm squeaks like a bird over bumps. It is loud to the point that a pedestrian said something about it as I drove by.
Is there a grease zerk that I missed?
Too tight / too loose?

Did you torque everything under load?

Good question. Installed with tires on, on the ground. Didn’t use a torque wrench b/c I couldn’t fit it on either bolt. Torqued to “good and tight”

Edit: Just saw that the spec is 118 ft/lbs for both ends. Will try to get a torque wrench in there tonight.

I just installed a set on my Boxster also.I did it with the Tire removed.
Easier to get the Torque wrench in there. As far as Tightening when under load I think that refers to the Lower control arm were it pivots on frame. Even then I dont see the point as when I torqued it down to 89 lbs the control arm would still pivot fine .The Tuning fork arm I dont believe the suspension needs to be loaded as (I did not) and everything bolted up tight on both ends with no play or spaces. The ball will move with the suspension and the inner bushing on the ball will find
its way strait as u tighten it up.same with other side(fork side) it will move because of the ball on other end and find its way flush when tightening down.I checked after I tightened everything down and it all clamped tight especially at 118lbs both ends.Just my take others may have different view.
I did try loading the suspension on one side (wheel off) with a jack under the control arm ball joint just to see and same result.The control arm will find its own centre.Its a slip fit . I think the rubber inside is designed more for vibration than twisting with the suspension.Your squeaking my be because it wasn't tight enough, these spec are important and should be followed.Or u may have a bad part.
I think TRW is not German like original stuff.I believe there made in USA now, lower grade.

Killed the birds with 118 ft lbs of torque.

Appears I may have a few "good and tights" to which I must attend.

Glad to hear the chirp is gone. Must have been annoying.