New guy here with a lame 930

Novelty Fashion · 10-08-2012, 08:21 PM

Hey all, I am (sorta) new here. I've got a lame 930. Not "lame" as in it sucks, but "lame" as in a mount with a busted leg. Poor baby needs some doctorin'.

I've got a 1985 930 which has 36,867 miles on it. A real survivor, it's totally stock, and mechanically is Euro-spec, while I'm working on returning it to Cosmetic Euro-spec. It came with the fender markers and Euro rear bumpers, so all I really need to do is Euro rear lenses and install the front bumper strips in lieu of the US-spec side-winkers. That will take some thought, as the guys who Federalized it wired the side markers as the "city lights", but that's a new thread for a new day.

My current issue is this: when I purchased the car in 2009, it had 35,220 miles on it, and had just been thoroughly gone through with $8,000 in receipts from a respected Porsche shop. It ran and drove perfectly. However, due to "life stuff", the car sat for long periods during my ownership, (1,600 miles in three years, I'm ashamed, but it couldn't be helped).

Anyhow, I am now back in a position where I can use the heck out of it, (as intended).

About 30 miles ago or so, the driver-side rear wheel started making a HORRIBLE noise. It sounds like metal-on-metal scraping and grinding. Just awful. It is VERY loud, but has no "rhythm" that increases or decreases with speed. Whether you are going at 5mph or 70mph, it sounds the same, maybe being louder at speed. It also is worst when moving forward. Backwards, it's almost totally gone, but forward brings it out. Even moving at 2mph in the driveway, it turns heads down the block. It's screeching and loud.

So I pulled the brake rotor off tonight, thinking I might get lucky and it would be a spring or some other E-brake hardware. Of course not, because that's my luck. The sound appears to be emanating from either the hub or CV-joint area.

Now, I'm trying to develop my plan. Does this sound like a CV joint and I need to do the axles or could it be a wheel bearing? From my research, bearings don't sound like this when they fail, but I'm open to anything. (I REALLY hope it isn't a bearing.)

I'll try and get a video up tomorrow with the noise, (and pics of the car). The hub is very hard to turn as well. The car has LSD, so I know I'm turning both axles and such, which takes more effort, but to turn it, I need to use a big screwdriver jammed between the wheel studs to get leverage. Is that normal? I don't recall my other car's tires or hubs being that hard to turn when off the ground.

Thanks for any help. I've got big plans for this car for Fall/Winter projects, then mods and fun projects in the Spring.

Tt surgeon · 10-08-2012, 08:31 PM

Warped rotors?

smurfbus · 10-08-2012, 08:43 PM

Are you sure the e-brake is adjusted correctly? If too close it will warm up and expand starting to brake all the time. Tuning the wheel would also be hard by hand.

Is the e-brake hub warm after a ride?

Novelty Fashion · 10-08-2012, 08:57 PM

I don't think it's brake related at all.

Regarding warped rotors:

Had cars with 'em. Caused more than a few. This is not warped rotors. Not there under braking, no wobble or shimmy and the sound is there when I turn the hub with the rotor removed.

E-brake:

Again, it does it with no rotor in place and turning by hand. E-brake hardware is out of the equation.

It has to be bearing/race or CV-joint/axle related. I'm scared to death of the former, (because of the nightmare of the work involved), and less so of the latter, (despite the added cost of two new axle assemblies).

infraredcalvin · infraredcalvin's Garage

Pictures required before any help is given, c'mon guys you're slacking...

infraredcalvin · infraredcalvin's Garage

Ok, now I feel like the a-hole sorry, but I still want pics of your car!

Never had a bad bearing, but did have a cv explode, stated making a knocking noise, then it would pop as the shaft stated breaking up the cage, finally the boot tore and the balls stated falling out. I would guess the bearing. You have to take off the CVs anyway to take a look, dive in, see what you get. See if someone on the board will loan you a bearing puller and get that bad boy back on the road.

mreid · 10-09-2012, 03:02 AM

You do realize that the e-brake has nothing to do with the rotor? There is a set of drum brake shoes behind the hub. Your problem sounds like the shoes are dragging (makes a horrible sound and the wheel is hard to turn by hand). Bad bearings usually make more of a clicking sound and cv joints clunk as you move forward or backwards. Depending on the condition of your parts, these sounds can be very different. Good luck!

equality72521 · 10-09-2012, 03:17 AM

My bad bearing issue caused a clunking AND squealing noise.

IMR-Merlin · 10-09-2012, 04:25 AM

Quote:

Originally Posted by Novelty Fashion

The car has LSD, so I know I'm turning both axles and such, which takes more effort, but to turn it, I need to use a big screwdriver jammed between the wheel studs to get leverage. Is that normal? I don't recall my other car's tires or hubs being that hard to turn when off the ground.

Thanks for any help. I've got big plans for this car for Fall/Winter projects, then mods and fun projects in the Spring.

Silly question, but do you have the car jacked up from the side or are both rear wheels off the ground? You will be spinning the wheel against the LSD if the other rear wheel is on the ground.

Do you have any play in the rear wheel? as in the bearing failing usually will cause the wheel to have side to side up/down play.

Usually a bad wheel bearing will cause a groan, not a metal to metal sound.

Do you have jack stands? Get the rear end up on jack stands, with the car running in 1-2-3-4th and get out and listen. It's the easiest way to locate the problem.

Hope that helps

Brendon

Novelty Fashion · 10-09-2012, 04:45 AM

Both wheels are off the ground.

No play in any direction, and I did start it and put it in first and get out, and it seems like the "whole thing" is screeching. Probably gonna have to tear it down further. Am not looking forward to this.

Quote:

Originally Posted by mreid

You do realize that the e-brake has nothing to do with the rotor? There is a set of drum brake shoes behind the hub. Your problem sounds like the shoes are dragging (makes a horrible sound and the wheel is hard to turn by hand). Bad bearings usually make more of a clicking sound and cv joints clunk as you move forward or backwards. Depending on the condition of your parts, these sounds can be very different. Good luck!

But when I removed the rotor, it exposed the brake shoes and springs and cable connectors, and it all is clear of everything that moves.

Miguel Antonett · 10-09-2012, 04:53 AM

Quote:

Originally Posted by infraredcalvin

Pictures required before any help is given, c'mon guys you're slacking...

+1

Bearing...

rsrfan · 10-09-2012, 06:45 AM

It's your wheel bearings. It happens with 930s that sit for a prolonged period of time. Just dealt with the same issue on mine last year...

Novelty Fashion · 10-09-2012, 07:04 AM

Ok, so here are some crappy car pics. As soon as I get her back on her feet, (literally), I'll get better shots.

Here's when I first took delivery of her. She still had the big silver US-spec sugar-scoop headlamps, and some cobbled-together "Federalized" muffler. She now has the proper Euro muffler and H5s, (I know they're not Euro, but I got a smoking deal on 'em. H4s are in the future.)

And here she is as she sits about an hour ago.

Here's a video of the hub turning with the engine on. The screeching noise is fairly evident. (Set the "preamp" volume in the player low, otherwise it'll clip-out and all be white noise.)

0001 - YouTube

dr3358 · 10-09-2012, 09:10 AM

Agree about the bearings, however don't be afraid of the cv's. Can be replaced fairly easily and easier to replace than rebuild. There are plenty of aftermarket cv's that work well with the 930, since they are used for off road use as well. Did all four of mine and it wasn't that bad. Just make sure you pack them with a lot of cv grease!

full quack · 10-09-2012, 10:27 AM

Wow just listened to your video/audio....sure hope those bearing races aren't spinning on your stub axle!!!!
That's just plain nasty sounding, good thing your at home in your garage, instead of 50 miles from nowhere.
The cost of rear bearings is not that bad, it's just a lot of work. Plenty of threads on that subject here on the forum.

Mark

JFairman · 10-09-2012, 11:07 AM

You said you can't see anything scraping in the emergency brake hardware and that sounds like big time dry scored up metal to metal scraping.

CV joints won't make that noise unless the outer CV bolts are really loose and the CV is scraping on the inside of the trailing arm recess where they bolt on to the stub axle but you would quickly see that by looking in there and the axle shaft would be wobbling. Or maybe a rock or something metal is wedged in there and scraping on the CV joint but I kinda doubt thats it.

The stub axle never touches the inner wheel bearing races so it should be fine. It has male splines and slides into female splines inside the hub that is running in the bearing races and then the big castellated nut on the end holds it in place there.

Look for a rock or something wedged in there alongside the outer CV joint and beyond that it's probably a wheel bearing.

fredmeister · fredmeister's Garage

This might be an obvious point but did you test it with both rotors removed. Sound has a funny way of transferring across parts and one rotor on the other side might be picked up on the side for the rotor you removed.
I would look like JFairman suggested for a stone or something wedged in the recess in the trailing arm where the cv joint bolts. Also see if the bolts are the right length and not protruding too far thru the cv joint flange and rubbing on the tranny housing....though you should have heard this before letting it sit for extended periods.
Something must have changed from it sitting if you did not hear it earlier before you stored it, which would indicate corrosion induced problems.
You could try putting a stethoscope or a wood dowel to your ear and placing it against the hub or trailing arm near the bearing while its running on blocks to isolate where the noise is emanating from. Just be careful not to catch it on moving parts.
I have heard rear wheel bearings do go on our older turbos.

Fred

Jim2 · Jim2's Garage

Remove the six bolts securing the inboard CV to the transaxle then you can rotate the hub/flange/axle assembly by hand and feel the condition of the bearing. Should be smooth. 10 minutes to do, but you will need a hex tool in the event you don't have one.

Also, now that you have the rotor removed, you might put the wheel back on and see if you can rock the wheel L-R and up-down to look for slop in the wheel bearing.

Nice looking 930.

.

mreid · 10-09-2012, 06:04 PM

Okay, I listened to the video. Wow! My 1986 930 had 38k miles and had to have the rear wheel bearings replace simply from sitting in one place too long. Sounds like yours has the same problem, but do as Jim suggests and disconnect the CV to isolate one side. You will find out very quickly if is the bearing. If it is, I hope you can replace them yourself as they are $3000 and up for a shop to do them. Good luck!

IMR-Merlin · 10-09-2012, 06:42 PM

THIS.. beat me to it.

Quote:

Originally Posted by Jim2

Remove the six bolts securing the inboard CV to the transaxle then you can rotate the hub/flange/axle assembly by hand and feel the condition of the bearing. Should be smooth. 10 minutes to do, but you will need a hex tool in the event you don't have one.

Also, now that you have the rotor removed, you might put the wheel back on and see if you can rock the wheel L-R and up-down to look for slop in the wheel bearing.

Nice looking 930.

.