oups59

Well,

I need help on this one. I have a strange sound near the transmission. At first, I though it was the torque tube but I not so sure.

At idle, the sound is strong and sound like a lose nut spinning in a can near the clutch housing. But from 1500 RPM up, the sound goes away.

I try to find exactly where it come from. I use a stethoscope and it is definitely coming from around the clutch housing no strange sound from the torque tube.

Any ideas ?

WallyP

If this is a five-speed, try gently pressing the clutch pedal - just an inch or two - and see if the noise goes away. If so, the plastic cup at the top end of the clutch arm may be bad.

oups59

It is a AT.

sonny1

Loose flex plate bolts,cheers,Sonny.

Garth S

The rivets used in early cars ( flex plate hub) often loosened - before bolts became the norm ...

sonny1

I have seen many loose flex plate bolts on later cars,cheers,Sonny.

onebad928s

I have somewhat the same problem im trying to figure out. When you step on the gas theres no or little sound, when the clutch is in theres no or little sound. Right now the cars on jack stands and i tested for sound by putting the car in gear while running and no sound. All together the sound is a clicking sound. Im thinking its the cv joints but i hope not since i replace them already once this since the fall.

onebad928s
83 928 5speed

SharkSkin

Did you get under there and re-torque the CV joints after driving for a while? That's something that should be checked, especially if you replaced the gaskets.

onebad928s

i didnt do that Dave but i will for the 3rd time or i will just wait since the rear suspension is coming out again since i got all new bushings and bearings. But the last time i had the noise i think my mechanic re-torqued them too and it stopped for a bit.

LOu
83 928 5speed

oups59

Any ideas on how to re-torque those loose flex plate bolts ??

oups59

Any ideas on how to re-torque those loose flex plate bolts without removing the tranny ??

sonny1

In the rear torque tube bell housing there is a hole in the lower part of the bell hsng.,you will be able to acess the bolts thru it,they are 6 in total,you will need a 13mm socket.,cheers,Sonny.

Garth S

Hummm ... are we talking about a front ... or rear flex plate ( "near the transmission "... and " near the clutch") if by "clutch', was 'convertor' meant? - if not, we are at the front - and I'm confused .

No doubt! - my point was that the early '87 S4s often had riveted front assemblies IIRC: The fix was to replace rivets with bolts, which must be correctly torqued as you pointed out. The car in question is an '87 - so the lower bell housing removal is the way in to see whatever the issue may be .. if the issue is here at all.
Oups59,
Remove the lower bellhousing ( likely will require the exhaust system to be lowered from the headers - watch the O2 sensor wiring!), and go in as if to loosen the pinchbolt to relieve any residual tension on the crank: if you haven't yet done this, now is a perfect time. Then, the [front] flexplate fastners will be evident: hopefully, they are bolts. IIRC, they are higher tensile strength bolts (gr 10.9 vs 8.8) , so can be torqued higher. Do not know the value offhand, but certain others do.

oups59

Garth,

I am sorry for the confusion but the sound is near the tranny so I suppose the rear flex plate.

Big Dave

When I had my transmission replaced, it made a peridoic rattling noises like a fan blade hitting something metal. It turned out to be loose torque converter bolts. It should be mentioned that the torque tube carries sound from one end of the car to the other and had me AND my transmission mechanic stumped for a few minutes. It was very difficult to tell which end of the car the noise was coming from.

If it's the flex plate, you can get at the bolts by dropping the lower bellhousing cover. With the tranny in neutral, you can use a 27mm socket to rotate the crank (from the engine compartment) to be able to get at each of the bolts. Just keep turning the engine little by little until each of the bolts can be exposed and torqued.