924Board.org

CorsePerVita · Joined: 25 Jul 2008 Posts: 1992 Location: Redmond, Oregon

started noticing an odd noise. not a grinding noise.... not a horrible noise... just a noise that is, well, faint, but definitely there. i notice is more if i'm letting off the gas with the car in gear. at first i thought "Must be a rotor" but i notice it does it hard on the gas, and off the gas. Maintaining isn't a big deal... and it goes away at highway speed. sounds sort of like a metallic rubbing (like when you have a car up on stands, and turn the wheel). i honestly can't tell where its coming from.

Here's the clencher... if i push in the clutch... it goes away :-/

so it sounds like maybe the bearings in the torque tube. on a scale of 1 to 10 in comparison to doing a timing belt on a 944... where is the torque tube at on replacing the bearings?
_________________
- 1977 Porsche 924 2.0 N/A (Trackday Project)
- 1979 Porsche 924 2.0 N/A (The other daily)
- 1980 Porsche 931 (Daily)
- 1987 Lamborghini Jalpa
- 1999 Ducati 900SS

924guy · Posted: Sat Jun 06, 2009 9:23 pm Post subject:

torque tube possible, so is rear wheel bearings going away...
_________________
Eric
78 924
82 931 SE "smokey"
99' VehiCross
Y2K Honda Insight
http://www.cardomain.com/id/924Guy
Performance by Pasha

Smoothie · Posted: Sat Jun 06, 2009 10:51 pm Post subject:

Remember just pressing the clutch while rolling doesn't stop the drivrshaft. You'd need to both press the clutch and put it in neutral..
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

CorsePerVita · Joined: 25 Jul 2008 Posts: 1992 Location: Redmond, Oregon

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

Clarks-garage.com has a write up on replacing the bearings on a 944. It doesn't seem that bad, but you have to be careful to not damage the bearing carriers.
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

CorsePerVita · Joined: 25 Jul 2008 Posts: 1992 Location: Redmond, Oregon

mgatlag · Joined: 02 Aug 2007 Posts: 647 Location: Avon, IN

well this one is hitting home with me... I just finished rebuilding my TT in my car this week. I took lots of pics along the way and am going to add a how-to on the site. If you want, PM me and I'll talk to you a little about what I found while doing my rebuild. There are DEFINITELY things that are on the NOT to-do list. I learned the hard way with the carriers. Let me know if I can help.
_________________
Michael
'77 1/2 924 N/A- 5 speed Audi box
'04 Ford Taurus - gone!!
'92 Jeep Cherokee Laredo - gone!!

Porsche... better than tea with Miss McGill
(Slap Shot)

CorsePerVita · Joined: 25 Jul 2008 Posts: 1992 Location: Redmond, Oregon

mgatlag · Joined: 02 Aug 2007 Posts: 647 Location: Avon, IN

yup sounds like the same noises I heard.
_________________
Michael
'77 1/2 924 N/A- 5 speed Audi box
'04 Ford Taurus - gone!!
'92 Jeep Cherokee Laredo - gone!!

Porsche... better than tea with Miss McGill
(Slap Shot)

benlg81 · Joined: 12 Oct 2008 Posts: 204 Location: West Midlands UK

same noise that i have been having issues with in mine what is the issue at fault then? and how easy for a novice in the garage?

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

With the car sitting still in neutral and the clutch out can you hear the noise? In this condition the only things spinning are the clutch, driveshaft and tranny input shaft. If you dont hear the noise it is probably something besides the driveshaft tube. However, it is always possible that driveshaft distortion under a heavy load causes the bearings to make noise that they dont make just sitting still. That said, in my experience, if you have dry or damaged bearings they will make some kind of noise even under no load.

If you only hear the sound with the car in motion it could be many things in the rear drive train.

joecitizennn · Joined: 12 Sep 2005 Posts: 2096 Location: no mans land

If you are thinking of removing the driveshaft tube you might as well throw a clutch kit in while you are in there. A fast man with a lift and tranny jack who knows what he is doing will be just over a half-day removing and installing a torque tube. If you dont have a lift or tranny jack or air tools dont plan on getting it done in a whole day. That is if you have another tube to install. If you are rebuilding the tube your car is going to be down a while.

A transmission being pretty easy to pull, I would try this test first. When you have a day free pull your tranny out. It is not that bad, just a couple bellhousing bolts, trany mounts, shift rod, drive coupler, and two CV shafts. Tranny jack would help, but a big floor jack and maybe a friend will do. With the transmission removed, use a stick to hold the clutch pedal down and crawl under the car and spin the driveshaft by hand. Do the bearings sound smooth? Is there a roar? THey may be dry. Is there binding? There may be failed bearings. Pull back and fourth on the shaft, does it move? It should not. If it does bearing insulators and bushings may be gone. Try to wiggle the shaft in all directions feeling for play, then slowly turn it while pushing or pulling hard on it feeling for binding spots or roughness. If the shaft spins smoothly and is solid in the tube you can probably rule it out as a problem.

Remember, your clutch disc will be ratteling on the other end of the shaft as you wiggle it around and spin it, dont confuse that as bearing noise. Start up the car and let the clutch out and listen to the whirr of the bearings in the shaft. There should only be a whisper.

With your tranny out, you can spin the input and output shafts of the transmission feeling for play or roughness, and you can also turn you cv shafts and wheels by hand. Taking the system apart in this manner nicely isolates possible problem areas eliminating confusion