Driveline noise

[Beasterman]

Hello,

A new to me ‘86 930 all stock, all original, 48130 miles. First 80 miles of driving was just fine and then heading out the other evening started making squeaking/grinding noise at any speed. Very describable from very low speed on up. Nothing at idle or with engine revs with car not in gear and stationary. Present when rolling and not in gear. Same in forward or reverse. Maybe worse in turns but not by much. Any idea what it might be? Was told to look for rocks getting caught in rotors/pads ... checked and didn’t see any rocks or signs of scoring around calipers, rotors or pads. Found a loose wheel weight and refitted it, but noise stayed.

Any help appreciated.

Tony

[aschen]

decent chance it is rear wheel bearings. My condolences if so they are a PITA

[voitureltd]

Unfortunately sounds like RWB. Over the decades a number of 930 I've had need some around 50K miles. When I look at the records it seems if they sit in one spot over years it happens more frequently. The shop that replaced them for me said to drive slowly a short distance or move back and forth at least once a year it will help. Better also on tires not to have the weight of the car on the wheels sitting unmoved for long time. An expense required of some low mile 930s. Not had many of the other air cooled models so maybe not a issue with those.

[Beasterman]

Thanks all. With the recent posts on wheel bearings it had me thinking that might be the case. Is there an easy test to confirm without pulling hubs, etc.?

[Chinook]

Howdy,
Depending upon the severity of the RWB deterioration one can often load the RWB either R or L by rolling at slow to moderate speed on a smooth quiet surfaced road or parking lot and swerve either R or L enabling the loading process. (ie. swerve Left loads the Right and visa versa) If the bearing is bad you can usually hear an increase in the bad bearing growl/noise when loaded.
Good Luck,
Gary

[mark houghton]

One other less dire possibility that I faced a few years ago was one of the rear emergency brake shoe springs broke. The spring was grinding on the brake drum surface. Very easy DIY repair. Next time you drive her and hear that noise, try gently applying the emergency brake and see if the sound changes. Alternately raise the rear of car off the wheels and rotate each wheel by hand to see if the sound occurs.

[Beasterman]

Thanks for this. Turns out it was a broken parking brake spring. Getting the caliper off to get access proved to be a challenge. The caliper bolts were tighter than tight. Springs should be here soon and the car back on the road. Thanks all for the help.