Loud knocking sound / different symptoms!

[palmhero]

Yesterday my 986 2.5L started to knock from the back / (subjectively right side).

Symptoms:
- audible only if in gear and moving
- NOT happening when cruising on neutral
- NOT happening / stops to knock when clutch is presed
- NOT happening immediately from start, only when car warms up
- more audible when climbing a steep hill
- I can also hear very similar sound but not so loud when I lower the right side of the car from being jacked up.

Visual inspection shows no rattle or damage on CV axle joints, I have old bushings (140k mileage), but I don't think they would hit so loud. It sounds somewhat like someone hitting wood with a hammer somewhere in the distance, but with force.

[palmhero]

yes, also: knocking is synced with wheel rotation. Same speed of knocks when in 1st, 2nd, or 3rd gear but the car moving at same speed.

[Anker]

Bad universal joint on the rear axle.

[palmhero]

Where is it located and what to look for when inspecting it?

[rfuerst911sc]

In your original post you stated " Visual inspection shows no rattle or damage on CV axle joints " please explain exactly what you did or what this means . The axle universal joint mentioned above is the same thing as the CV axle joints . Usually but not always the first sign is the CV joint rubber bellows/covers are torn and throwing grease in the wheelwell or under the chassis . But a CV joint can be bad and still have good bellows . Classic symptom is a clicking or knocking noise as the axles rotate .

[palmhero]

I'm changing the "coffin arms" with bushings next week, will buy an axle joint from a dead 986 I found nearby to have it in the trunk when I'm doing the bushings. I'll remove the CVs and examine them.