With new wheel bearings and bushings and the shims reinstalled just like they came off - - - Is it necessary to get a new alignment?

Yup. A safe bet is to loosen the adjusting bolts again (same ones that hold the shims) and push the arm as far forward as you can. Then drive cautiously to the alignment shop.

With the bolts loose, you'll note that there is a lot of fore-and-aft slop where the outer end of the trailing arm attaches to the chassis. This slop is how you set your rear toe angle.

Toe-out in the rear eats tires. Pretty quickly, too. It also makes the back end of the car want to become the front end. It can be entertaining, but the entertainment quickly wears off...

If you are confident you can set the trailing arm exactly where it was, with absolute precision, you don't need an alignment.

If you're a mere mortal like the rest of us, you need one. You can use strings and a measuring tape to do it, or you can take it to a shop.

--DD

I would disagree. If you have replaced the bushings, there is a good chance the slack you have taken up with new bushings is now enough to cause the previous settings to be inaccurate. Whenever any components are replaced on a suspension, the car should be re-aligned. If nothing else, as mentioned previously, you are risking tearing up a set of tires.

Full disclosure though, I just replaced my bushings and I have not re-aligned the car. But it's on an old set of tires and we will align it before the new track-intended tires are installed.

I completely agree that with your disagree we all agree. alignment it is. Thanks.

Oh, good point!

--DD