Rear knock - trailing arm bushing?

[boon]

So over the weekend I did a complete strip and rebuild of my rear struts.

As part of this I made them considerably softer so they now actually have meaningful bump travel, where previously they were a bit ridiculously hard.

Taking it for a gentle test-drive down the street I immediately noticed a bunch of clunking/knocking from the back end, so I put it back in the garage and went over every single nut/bolt I had touched, assuming I had left something loose. Everything was tight, and the struts are freshly greased so I'm going to go out on a limb and say it's not them.

It can be quite a loud clunk/rattle/knock and it only happens on smaller bumps - I can take a speed-bump at a reasonable pace and they're silent.

I got under the car and had a bit of a pry/wriggle/push and noticed that the front bushes on the rear trailing arms have a lot of give. If I rock the car hard forward/backward I can feel maybe 4-5mm of play in that bush. Is that normal-ish or is the bush shagged? Visually they look OK. Also is this likely to be causing my clunking?

I have some PU bushes kicking around that are for that spot but from a bit of hunting on the internets it looks like a bastard of a job. If only because I had a brief go at the trailing arm front bolt last night and it was apparently the tightest bolt in the world, I think it's going to need a jack on the end of the breaker bar to move it.

EDIT: Hrm, could this also be swaybar end links? They felt tight from a hand-wriggle but I'll look at tightening them up tonight.

Edited November 15, 2015 by boon

[Rosssub]

If you don't have any luck with the sway bar links, it could well be the trailing arm front bushes. I left them till last after replacing every other bush and got a lot of knocks/clunks because of them. Mainly on uneven ground and a single clunk when going from reverse to first. There's a few pic's and a rough how to on post #14 in here:

http://clubsub.org.nz/forum/showthread.php?40802-Rosssub-s-Suspension-Bush-Upgrade/page2