my heart sank.......

Enthuzed1 · 06-11-2005, 11:25 PM

hey everyone, lets see, where to start......

i was at a stoplight, and i don't know what the hell was going through my head, but i was shifting through all gears to see how much play i had, and i was in second gear when for some reason i let go of the clutch (i thought i was in neutral) when the light turned green.....so obviously i stalled......well, turned the car back on and i notice this clicking sound coming from the rear of the car, in the transmission area....as i shifted up the gears the noise was more prominent and the car shaked.....so i bring it to the garage and check everything out...nothing's loose, and i replace the gear oil for the hell of it.......i just changed gear oil 500 miles ago, and the stuff i drain is dirty

so i do all this and start the car up again and take it for a spin.....
well, the noise and shaking was still there, and gets worse as the rpms go higher......i decide to go down the street, and i shift to second gear

i hear and feel a loud crack from the back and it feels like my rear end keeps going over a large speedbump......whenever i moved it was like something was banging the underside of my car....even in neutral, it was the same thing.....I could shift into gear fine, but that violent thud was always there....so i had to very very slowly crawl back to the house, my heart breaking more each time i heard and felt whatever was going on under there..........
i haven't taken a look under the car yet, but my dad said it might be the differential shaft (or the torque tube in our case)
i would greatly appreciate any help to find out what's going on, so i can get ready to use up all the money i don't have..........thanks guys

iwaskilled · 06-12-2005, 12:08 AM

If it does it in every gear then you probably broke a tooth on your ring or pinion gears depending on how frequent the thumping noise is, if it is fast thumping at low speeds then its the pinion. this can be visually verified by pulling the side of the differential housing off, you will have to remove one of the axles to do this.

SoCal Driver · SoCal Driver's Garage

If it is the ring and pinion then you have been doing burn outs and hard shifting to spin the tires.

Now you get to pay for it.

Might also be a broken CV joint or axle.

Or both.

Enthuzed1 · 06-12-2005, 04:27 PM

oh don't worry, im well aware of what burnouts and hard shifting can do

well, i guess i'll pull out the cv axles to start and hopefully it's just that......the boots on the cv joint boots are still in tact but can they still get damaged? either way, i'll look around and i guess this would be a good excuse to get a new tranny, torque tube and clutch right? ok i'll get back to you guys.....

mike944 · 06-12-2005, 04:39 PM

Yes, the CV's can be damaged, even if the boots are still intact, but not the kind of damage you describe. The problem is likely the ring & pinion. At this point, just pick up a used transmission. The broken ring gear pieces have had a chance to get around the transmission internals, and have probably damaged a good portion of the gears. It would be much cheaper to just replace the transmission.

If the problem were your CV joints, with the effects you describe, your CV's would probably be completely separated, maybe a sheared bolt flange.

88BlueTSiQuest · 06-12-2005, 06:53 PM

Wouldn't a snapped CV shaft render the car immobile, unless it had an LSD rear end?

One busted CV shaft would have the same effect as having 1 tire on ice, the one tire would spin but the car wouldn't move. So, the output shaft for the snapped CV would spin while the one good drive wheel wouldn't operate.

iwaskilled · 06-14-2005, 08:45 PM

I actually have a used ring and pinion set from my old transaxle, if you nee one...

TSNAPCRACKLEPOP · TSNAPCRACKLEPOP's Garage

i am hoping it is your cv joints. mine never made a sound till i pulled out of the tollgate at the end of the kansas turnpike after a trip to denver, and back. the noise was so gut wrenching that my heart also sank (thought i screwed up on my engine reassembly the previous week), but the car would still go, so i drove it about 50 more miles, then rebuilt them....yes, took them apart, cleaned them, greased them, reassembled in different configuration,reversed the stress, and still driving it now, about 3k miles later. no sound, and no heat.

tifosiman · tifosiman's Garage

Ring and pinion.

A used set is worthless, because it would cost more than a used transmission to install them and get them shimmed properly.

Start looking for another good used trans, so that when this one goes, you will have a replacement. Go easy on it in the meantime, especially on 1st gear launches. If you launch hard when the gaps are lined up (where the missing tooth is), you will shear more in a rapid fashion and create some nice metal granola bits.

FYI, burnouts and hard-shifting are not the only culprits for r&p failure. There are other issues that contribute as well, including driving while having a bad clutch center, and lack of maintanence (r&p should be checked and re-shimmed at specified intervals).

fast924S · fast924S's Garage

Sounds like you blew the ring and pinion, I have blown up 3 on my 87 924S trannies, Its gonna cost alot to rebuild (brand new ring and pinion approx $700 $1500 labor and full tranny rebuild), your better of getting a used tranny for like $500

josephsc · 06-15-2005, 09:15 PM

What you described is exactly what it felt like when I grenaded my tranny. If you pour out the gear oil again and find metal shavings -- that's a pretty good indication. You can open up the tranny case to find out for sure. If that is the case, I'd also recommend going with a used replacement tranny.

Porsche-O-Phile · Porsche-O-Phile's Garage

Replace the transmission.