mtl968

Hello everyone, I have my beautiful 968 for 2 months now (107K miles) and was soooo happy but some clouds are becoming to blurr my happiness ! I'm hearing some metallic unusual noise from the back under, mostly at speeds over 50, when decelerating. I changed tranny fluid and there is no metal shredds what so ever, but noise still there. I googled a lot and it seems that transaxle pinion bearing failure is the usual suspect in this case...

Something else happened like 3 weeks ago, I was pushing the car a bit (but not too much) and got an awful sulfur smell - kind of natural gas - I read some place this also can mean my tranny is dying.

Another thing was some hard knocks coming from under the car when I was downshifting 4 to 3 (maybe 6000rpm in 3rd) I was really scared, maybe 5-6 fast and heavy knocks like something breaking under the car and hitting - I clutched to neutral and braked heavy and it stopped. I thought maybe some rev limit stopped the engine or so but I am pretty sure I wasn't in the red line. Or maybe the clutch is too used...
I was careful to brake before downshifting after then and it didn't happen anymore, but a few days ago I felt slight knocks again as I downshifted 3 to 2nd maybe 4000rpm which is pretty low !



Any of you have an idea what my problem would be and if these 3 symptoms are related ? I'm driving the car a few days a week but all have to be all smooth, I can now compare myself to those 65+ years olds that go out with beautiful Porsches and Ferraris all over Montreal for the F1 Grand Prix and run 40 km/h... I used to make fun of those people !

I was planning to do some mods to the car (nicer bigger wheels, exhaust,...) but I feel my budget is gonna go to transaxle and other maintenance...wellcome to the club you'll tell me ! I was expecting that but not thaaat fast.



Cheers,

Daniel

odurandina

http://members.rennlist.com/martin/index.htm


http://members.rennlist.com/martin/faqs.htm



Symptoms: Road speed related whine audible from 35-40 mph...


Test on straight road with smooth surface for minimum tyre noise. Close roof and windows, accelerate to 80-85 mph, lift off, if you hear noise resembling a jet plane slowing down on a runway - you have a problem ! Alternatively you can secure the rear of the car on stands, run the car in top gear and listen to the noise from the gearbox. If you haven't got LSD you can stop one or the other wheel to eliminate possible wheel bearing and CV joint noise.


for a hard-driven, early "68" you could be getting closer to tranny rebuild time or worse.


you may be looking at bad 2nd and 3rd gears. (common situation, and why i won't be downshifting my gearbox hard until rebuild time).

http://www.jhmotorsports.com/shop/ca...products_id=10


new gears will be (about $1,500), add to rebuld kit from the same guys ($1,100)


set it up for more top end: (add $700-$1,400 depending if you do 5th and 6th or just 6th gear)

http://www.jhmotorsports.com/shop/ca...products_id=45


unfortunately, not a do-it-yourself job for most mortals...

techartisan

"Tranny noises, smells and strange knocks...any ideas please ?"

quit staying in cheap motels.

John_AZ

odurandina
Slayer of Economic Optimism,

Thanks for the information and links.

John

mtl968

Thank you Odurandina. I tried the test and it's positive, the metallic sound is there even when I accelerate...
Btw, I didn't know the 968 tranny was the same as for Audi S4&RS4 B5...may give me more chances to find a nice one or to rebuild...
I guess I should count my pennies to see where I can get...used or rebuilt...
Have a nice one

Daniel

peanut

are you serious ?

Lets see....... you dropped the clutch in 3rd on 6000rpm and wondered if the banging noises from the trannsmission was important ?

mtl968

I don't get it peanut...if I'm doing let's say 4000rpm in 4th and I downshift it goes somewhere not far from 6000 in 3rd thats nice enough to pass some corners...if you say that's too much for a Porsche to handle well I would go straight back to my old E36 Bmw M3. Come on !

I_am_imprezed

if ur rev matching those downshifts its probably not too bad...on the tranny at least. but theres of course valve wear to consider. You shouldnt need 6k revs especially on the street to make it through a corner. 4k in our car is really the powerband anyways..