thesauce

My 1984 911 has recently developed a mysterious clicking noise. Can anyone help with a diagnosis idea? I sent this video to my mechanic who is stumped. The noise is intermittent, changes cadence with the speed of the car, sometimes goes away when the car is taken out of gear at speed and sometimes does not. It is coming from the rear of the car.
Here is a link to the video, any help will be very much appreciated!!!
Thanks

-edit-sorry for the size of the car pics, newbie mistake!
I know I am supposed to post some images of the car so that's what I tried to do, next time I'll resize them first.
Thanks again.

Amber Gramps

CV joint.

Reiver

Does the same noise appear when not moving and you rev the engine (engine tic) or is it in the drive train?

Reiver

CV, wheel bearing, sounds like it happens under load.

thesauce

Yes, it happens under load only, never when revving at a standstill.
I'll recheck the CV joint thanks!!!

redridge

def mechanical... I would start pulling on anything.... sway bars, cv joints, tie rods, lug nuts, loos nuts and bolts in the engine bay... in other words, something is loose.

theiceman

pull the cv joint , clean with warm soapy water and inspect. probably outer ...

thesauce

Yes looks like dirt/dust buildup in the CV joint. Guess I need to stay off the dirt roads.
Injected some grease in the boot and it quieted right up.
Thanks for the help all.

Amber Gramps

Boom!! How do you like me now?

Kidding.

Let's not stop at grease. The joint is trying to tell you something. It is time to replace if it is making noise.

ron mcatee

Time to replace them or remove, clean, repack, and reinstall CV's

Steve Weiner-Rennsport Systems

Absolutely! In many cases, we find that the axle splines are so worn that we replace the entire axle assembly as a cheaper alternative.

Ed Hughes

So, I have to comment. It is time to find a different mechanic if he couldn't figure out the two primary candidates for such a noise,

Amber Gramps

Yep. The completely insane part about that part of the story is that even I could tell what the sound was and I only have 40% of my hearing left. Seriously needs a new mechanic.

The other question I have is how the heck did he add a squirt of grease to a sealed boot? Did he open a boot clamp/circlip or does he have two part boots like on a bug? ....or does he have a ripped boot? Why is dirt building up on the boot anyway? Sorry, I just need to shut up, don't I?

OP, please don't mind my rude questions, I really enjoy cars way more than I should. I've had an affinity for all things mechanical since I was a toddler.

Yes, this is just a glimpse into my tool box. This is my Metric Socket drawer. The second drawer is just as crazy.

Oh, and knowledge is your best tool.

thesauce

Thanks guys,
Knowledge is definitely the best tool and one that I don't have much of-which is why I came here.
The answer to the grease access to the sealed boot question (and how the dirt got in there in the first place) is they are vented boots apparently to help disperse heat from the LSD. If that sounds ignorant, I am repeating the words of my mechanic who has worked on the car for the last 14 years including two previous owners. I will have him pull the CV joints and see about either cleaning/repacking or replacing the axle assembly as needed soon.

My caveat: I have been mechanically declined most of my life and have only recently gotten comfortable being inside machines because for the last two years I have owned a 50 year old Triumph Bonneville that demands my care. The Porsche still feels a little intimidating and anything beyond changing my oil I have left to the professionals.

theiceman

The Porsche is actually easy to fix so don't sweat it. It will come with time.

Many cv joints aren't sealed at the small end so often a squirting will fix the noise . The problem is though if it's clicking you are likely too late and have worn through the polished surface into the casting.

Replacing a cv joint is easy if not messy. If you are unsure just replace the half shaft and bolts. Then retourq at 500, 1000, 3000 miles.

Good luck.