968 Newbe Questions x 2

Bags · 10-09-2007, 09:16 AM

Hello everyone. I am a 911, 993, 997 owner but.. I found this very nice 92 968 for my son with 62K miles. It is red with the cashmere tan interior. It is in very good shape cosmetically and mechanically except!!!!!

1.) There is no lock out into reverse. The close proximity of 1st to reverse can be a problem especially for the less experienced (my son). I would hate for him to back into a little old lady at the light! Is there a simple fix for that?

2.) There is a distinct metal sound coming from the rear end. It increases in volume as you increase in speed. I would not say it is a grinding noise but it is definitely a metal rubbing sound. It does not appear to be coming from the CV, wheels, or brakes. I was wondering if anyone could shed some light on this subject for me. The closest Porsche dealer is over 100 miles away. My local mechanic said the noise was in the rear end but did not know what it was without taking it apart.

Thanks for the help....

968TomR · 10-09-2007, 11:44 AM

That is most likely the pinion bearing. The 968 had a number of pinion bearing failures and it is considered a known issue with the car. Search this forum and I am sure you will find quite a few threads about it.

Tom

callmethewander · callmethewander's Garage

^ yeah, that's not a rear end it's a transaxle, get up to about 50-60mph and shift into nuetral, does the sound go away, change, or stay thew same. if it stays the same i would suspect bearings or brakes.

callmethewander · callmethewander's Garage

also, would you like to adopt me?

flash968 · 10-09-2007, 04:09 PM

no, there is no lockout, but it is generally not an issue, as it takes quite a bit more effort to hit reverse

if it sounds like a 727 in the back (high pitched whine) it's the pinion - this is a common problem, but not the doom and gloom it has been made out to be - it affects about 5%-10% of the cars, and is not mileage related - it is a tolerance accumulation error and caused by too much preload from the robotic assembly

if it is more of a low growl, it's the axle bearing

if it's a metallic scraping, it's likely the parking brake retaining pin that has sheared

Bags · 10-09-2007, 07:52 PM

Thanks everyone for the great input. A couple mechanics I know agreed with your advice on the pinion bearing. Is is interesting that the owner of the car for the last 4 years states that the noise has been present for about 3.5 of those years and has not gotten worse. He drives the car about 1 wk/month and no track events. There has been no noticeable performance change. He was advised to wait until the noise got worse before he fixed it!!! (not exactly my approach) With that being said, how long can this go one before it falls apart???
Callmethewander: I'm preparing a room for you, just don't make my other 3 kids jealous!!!

callmethewander · callmethewander's Garage

haha, i have 5, maybe i'll take you up on that room, even tho i might be old enough to be your father.

Aufgeladen944 · 10-10-2007, 05:44 AM

I'm not too old, though! You feel like paying my tuition, too?

Damn, though nice pickup for a kid. Is he a good driver? Or is this like his first car? Watch him with it...I was a terrible driver when I was 17.

flash968 · 10-10-2007, 07:00 AM

how long is entirely dependent on how much preload is there - it varies from car to car, which is the root of the problem - it could go on forever, or it could grenade tomorrow

in case it isn't obvious, you don't want it to grenade - many VERY expensive parts get buggered in the process

p.s. - this would be the time to install lsd if you don't already have it

Bags · 10-10-2007, 04:10 PM

Flash 968: Good point on the grenading, I have been told it may be cheaper to find and replace the rear end with a used one (hopefully from a reliable honest source) that has a LSD in it that it is to open and repair the existing unit. I know this can vary from a labor standpoint and regioinally. However, being a bit mechanically minded the replacement sounds more doable than the repair. Am I thinking crazy here???

Aufgeladen 944: I wasn't really looking for the car, a friend gave me a call since his wife was upset that he has to many cars, a problem even I would like to have. My boys have been sharing a car for the last 2 years which is good. The oldest (18) is a good, safe driver. No tickets or accidents. In fact he had his first DE event last month in my 87 911 and did great. I know it is a sweet ride for a kid but he is the appreciative type and will respect what he has. He knows he is on his own for his next car..

Thanks again for the help

flash968 · 10-11-2007, 08:28 AM

all in, you're in for about 3 grand if you have a shop do the bearing and install a GT lsd - more if you go oem lsd

a good used unit is likely to cost you about 2k, but unless it has already been done, you have no idea when that pinion bearing might go, so you could end up right back where you started