help with analysis, please?

sbmackie · 11-30-2012, 09:12 AM

Symptoms: driving home from AX event a couple months ago; under braking, a soft "clunk clunk clunk" appears, right side of car. "Hmm" says I and pull off to parking lot. Take a look see, nothing loose or hanging, so back into car, no sound. Attribute to nothing and move on.

Do another AX event and a track day. Nothing unusual.

Yesterday out for a spin on a lovely day, start hearing same rhythmic (with speed) clunking noise. Starts faint, and infrequent, then gets louder and infrequent and intermittently firm and constant. Tried loading and unloading suspension, braking, etc. No change. Get home, take right rear wheel off, push pull wiggle, things seem tight. Spin hub and hear a rhythmic scraping noise from half shaft inner boot. AHA. So I push and pull half shaft in and out against spring pressure, put wheel back on...and no noise under load or braking.

Any ideas?

Scott

Ideas?

kodioneill · kodioneill's Garage

Year and model would help but it may be a failing C V joint or possibly broken emergency brake pad or spring.

kimlangley7 · 11-30-2012, 03:30 PM

"clunk - clunk" to me says CV joint

ossiblue · 07:00 AM

Quote:

Originally Posted by kimlangley7

"clunk - clunk" to me says cv joint

^^this^^

Nine9six · Nine9six's Garage

Search for "CV rebuild" or posts by "Grady Clay" if you want to DIY.
Hree is one such thread: Carrera CV Boot Replacement

sbmackie · 12-01-2012, 04:14 PM

The car is a 1982 SC with 78K on the clock.

sbmackie · 12-01-2012, 04:21 PM

Forgot to mention: When I took the wheel off and spun the hub, I could hear a "tschick tschick tschic" that I THOUGHT was coming from the inner axle joint area. I'm assuming the E brake noise would be on the hub itself.

Other then buying the a new axle (in lieu of tearing down the old one and repacking, it IS 30 years old), what other bits should I get that I can't see from the outside?:

Thanks
Scott

HawgRyder · HawgRyder's Garage

One of the quickest ways to determine a 1/2 shaft or wheel bearing failure that I have found is a sharp (slow) turn in each direction with someone walking beside the car listening for the sound.
Try it on the flat in a local parking lot .
It is the fastest way I know to pin down the bad side and determine if it is front or rear.
Bob

sbmackie · 02-03-2013, 03:37 PM

Update: So, had half shafts inspected at reputable tech, also looked at ebrake, tightened a couple loose whatzits, nothing else found. Drove home, no issues. Car parked for a month. Take it out tonight, after 60 minutes of suburban and freeway driving...the same noise. Isolate it to the right rear wheel. Not associated with clutch, whell or engine loading, or engine revs, just wheel speed.

Scott

mpetry · mpetry's Garage

By "inspected" do you mean that they took the boots off ? Or just wiped off the grease.

Did you check / torque the inner and outer halfshaft attach bolts, with special washer ? The book says these are replaced every time.

If a halfshaft lets go at speed, it does a heck of a lot of damage.

manbridge 74 · 02-03-2013, 03:58 PM

"Looked at ebrake"

Meaning they removed rear hub and expected springs/shoes?

sbmackie · 02-05-2013, 12:34 PM

Hmmm, those are both good questions. I'm assuming my trusted tech did torque and washer the bolts correctly. He said he "inspected" the ebrake. I will get clarification.

It just isn't consistant enough for me to think it's the half shaft.

80-911SC · 80-911SC's Garage

the words "trusted tech" are sometime not one in the same ....

SteamWolf · SteamWolf's Garage

here's another one from left field; the little plastic centre caps on my original fuchs are a little loose and one in particular makes this noise at low speeds LOL