A number of rants have been posted about rear wheel bearings going bad, due to quality defects or installation abuse.

1st question: how do you know when a (rear) wheel bearing needs replacing?

2nd question: can the trailing arm contribute to bearing failure, and if so, in what way?

I recently replaced mine, though I find my (Pagid blue) brake pads "sing" when I corner. Bearings, or just brake pad personality?

Pads.

Wheel bearings would grumble or moan all the time, and be much worse when turning away from the bad side. You would also be able to wiggle the roadwheel and feel "clunking" as you did so.

--DD

Don't forget the hot to touch, so long as you have not been on the breaks excessively.
L. McC

What DD said...a pretty constant moan and groan that would be hard to ignore. (Unless your car is as loud as mine.)

If you actually had a bearing "break" it would be impossible to ignore as the car literally steers itself. Rear wheel steering in a 914 is NOT fun; you start to turn into a curve and the car changes lanes...

yupp, what he ^^^ said ...

it'll "talk" to you before it fails ...
Andy

In my case, the rear wheel bearing would become noisy only after some fast driving (track days, on/ off ramps, etc.) and would make an occilating howling noise. After I replaced the bearing I inspected the old one and found what appears to be corrosion on the bearing face. Probably from sitting for a long period of time. I did the replacement in my garage by removing the trailing arm and using the BF hammer method.

John,

I haven't experienced this myself, but I understand if the hole in the trailing arm gets oversized it will drastically reduce bearing life. I think this more of a common problem with 911's using the steel rear trailing arms. I don't know of anybody that's replaced a 914 rear arm because of this problem.

Kelly