OK this is what has been done.
Changed complete axle on right hand side, includinf cv joints and boots at both ends.
New spark plugs, new transmission fluid, new fuel filter.

I am not addressing it as a cv joint problem anymore as the noise oily appears when in gear and at high rpm. Out of gear I cant replicate the sound. Would the radial seal cause this? It sounds as if teeth somewhere are skipping or jumping over each other.
I'll have to pull the covers this weekend and see what's going on under there

I'll keep you posted.

If it were a CV issue, I would expect it would increase with speed, not RPM. Rather than investing in a bunch of parts, you may want to invest in an electronic ear for $100. 06606 - Steelman Tools It can be useful in situations like this when a noise only happens under load. I have a suspension noise that only happens in certain situations, so I am probably going to do the same. Tired of fixing things that aren't broken. You can always sell it on eBay when you are done too. Heck, maybe I will buy it :)

Hey,
ok so here is another video. is this noise/ play normal for a cv joint that is at the transmission end?
911 sc CV joint to transmission. - YouTube

Just went out under my 81 that is on stands and did the same as in your video. No difference in sound or travel of shaft. Even the CV joint housing moved in and out a wee bit from the side of the trans case just like in your video.

There was no rotational movement when twisting . Look like you found the same.

Take the covers off and get a wrench on those exhaust head nuts. A wrench to check if tight.

Also, you have not mentioned closure on the exhaust being loose "like the welds came off" Can you post a pic of that or did you clear it up?

Ok I'm joining the OP in this quest to diagnose/discover the cause the this noise. Why? Well I have the exact same symptoms on my 81 SC!

I have changed out both axles like the OP, rear bearings good as well....
As the OP, right rear, knocking/heavy clicking...
My gut tells me this will be expensive.

Car is going In to TRE (for suspension refresh) some time soon so if I can't solve the issue...

Will keep this thread posted in hopes of helping OP. 2 SC s are better the. One, right?

911Freak/others - Listen to the noise in the OP's youtube video starting at 14 seconds in. Listen to it several times from that point forward. I swear it sounds like exhaust escaping. However, wind and road noise may alter the sound some. It just does not sound mechanical to me.

911 sc - YouTube

Listen several times. It is possible it's air not metallic; that sound invokes a visual almost like a cylinder head rattling against the case?!

My noise is also directed out from the right rear of car.

However, this same sounds is how my car sounded initially, now it starts rattling after rolling away from a stop, getting louder and increasing with road speed not engine rpm. It's now accompanied by a grinding/gear whine that matches the rattle/knock as road speed increases?! It's getting more of a gear whine then air movement.

Today I will drain the trans fluid and look for metal particles, pop off the lower valve covers and inspect head studs....

This weekend new axles went on both sides, drivers side was totally shot, passenger side was slightly loose, but not blown out like the other side, I changes it with new axle anyways... That's the last new part I install before finding the issues!

My gut tells me this is my diff going bad.

Any idea how to diagnose a bad final gear?

I'll check back when these inspections have been completed and include pics...

Jason

mirror bras
 

Hey all, I' m searching for "RED" mirror bras for my 1987 911c. Stock mirrors now but I guess I could switch out to accommodate the bras. Any Thoughts??