newworld

87s4 aut.

this is vague i know. but i put it outhere. i have a a rattling noise below center console only in park. in drive or reverse, noise dissapears.

i first thought heat shields, muffler etc. but i dont think that is the culprit.

all flexplate bolts tight etc. flexplate flat as well.

i am now thinking this could be torque tube rattling? curious is anyone else has encountered this? as i mentioned on drive and reverse, no noises whatsoever.

it is a very light rattling noise. if it is torque tube issue, is it possible to put gear grease to quiet the noise?

Kevin in Atlanta

Torque tube is likely culprit.

17prospective buyer

Sounds like torque tube bearings maybe, whats the mileage? Taking the torque tube out involves taking the tranny out with it, not a small job. AFAIK the bearings are nothing special but it's the labor time that kills you. Disassemble rear suspension a bit, unbolt axles etc. How is the noise when you rev it in park? If it goes away at certain RPM's it could still be something rattling, it's a bit like resonance/drone in an exhaust works, except it's vibration related.

I don't work on 928's for a living like some mechanics here though, I'm sure they'll chime in.

Here's a video walk through of the whole process, to familiarize yourself.

Chalkboss

Did you verify the flexplate to TC connection? On some 87s this is a riveted connection, and some have reported rivets which become loose and produce a rattling sound. I have narrowed mine down to this but have yet to rip everything out to fix it. A search will produce quite a bit of info.

James Bailey

no way to lube the bearings and would not help anyway...

Bill Ball

Classically bad TT bearings cause a rattle or growl throughout the RPM range, in gear or not, and accompanied by vibration. In your case, I would probably live with what you have until it either gets a bit worse and fits either a bad TT bearing or something else or you are able to definitively localize the sound (hard to do with the drivetrain). I've had a whining noise that sounds like a noisy fuel pump, but only in park and neutral (disappears when any gear is engaged), that has been present and not changed over 5 years. I suspected it might be bad torque converter (TC) bearings. I replaced them (and eventually the TC and primary pump) - the whine is still there and unchanged. So, at this point it's just part of the car's character until it more clearly declares itself.

It sure could be the rear flexplate rivets that bond the center of the hub to the plate, still present in 87MY. Below is a bulletin on that. If you can localize the rattle to the torque converter area, that might be it. Short of removing the TT and TC cover to look directly at the rivets, I don't know of a way to be certain. If you do determine that is the source, you might as well replace the TC and TT bearings as well, as they are certainly WYAIT type tasks.

jeff spahn

The most surefire way to fix this is:

Have Constantine build you up a new TT with Super Bearings
Get another Torque Converter cover with new bearings pressed in already. This way you can also inspect the bolts/rivets in the replacement cover.

Have a TT/Trans party. Provide lots of food and beer. Having the TT and the TC cover done and ready to swap will save about three hours of work.

You can bang this out in a weekend easy, easy. Cost you about $1500-$1800 depending on other parts needed but could be more if you do lots of WYAIT stuff like trans soft lines, brake lines, half shaft rebuild.

Get it done and check that off your list for 100,000 miles or more!

newworld

Thanks all for responding. I think bill ball is on right track....there is not whirring noises and nothing under load. It is especially louder in park when there is no pressure on drivetrain.

Torque converter rivets being loose is a top suspect.
Sounds like 2 plates clanging together. Metal plates similar to heat shield clanging.

Upon reading literature the cure is to drill rivets out and replace with bolts.

I would think torque tube issues would be present under load. Right now under load quiet at all rpms.

Bill Ball

Although I suggested it could be the rivets, note that I added you're going to have everything out to do the other jobs - the TC and TT bearings - even if they aren't needed at the moment. I did the TC bearings, although the originals looked and felt like new at 200K miles. I tried to do the TT bearings but short of buying a ram, I was unable to get the bearing carriers or shaft out. I tried all the usual techniques and they would not budge. So, I evaluated the shaft and bearings and found them quiet and snug with minimal play and no freewheeling (still had grease) and decided to leave well enough alone for now. It's surprising to see this at over 250K miles. Most fail at around 100K. I've seen them literally fall out of the tube on other cars. Not mine.

Let us know the final result.

newworld

thanks for comments. the noise is a bit annoying, and if it were a simple fix of course i would do it immediately. removing tt and tc etc is not something i want to get involved in at this moment. if the 2 plates were loose, i wonder if a quick fix would be the put some epoxy weld etc so the plates are snug. i dont know if the plates have enough of a gap to get anything in there though.

i realize there is a correct and right way to do things, but sometimes and i mean occasionally work arounds do work at least for a year or two....

newworld

I removed exbaust and found front flex plate bolts a bit loose and there was an intermediate clamp for exhuast clanging on exhaust.rear torque conv area rear pinch bolt retightened....when i hit with rubber mallet no rattling...noise is now gone...