02' C4S diff issue

A grinding noise appeared on MY 03' C4S. It seems to grind the most under accelaration. The Porsche stealership had a look at the car and said its a Differential issue? a couple of questions: -Is this a common issue? -Can the Diff be changed? (Porsche only has the whole gearbox as a part) Any input here is appreciated. Cheers

Quotes source post: 11105233

Since I have an AWD 996 Turbo some time ago I asked the techs about problems with this system. Not too many problems I was told. Once past the infant stage they tend to last and last. When I asked if they ever had to repair one the told me they replaced a front diff or two under warranty. I asked what symptom justified the replacement and was told the unit made noise. Generally items like diffs, trannies, engines are not rebuilt at the dealership but simply replaced with new/remanufactured. This is to reduce the odds of the rebuilt unit coming back. I'm not sure if the front diff can be rebuilt by a shop that specializes in transmissions/diffs. There's the know-how and then there are the parts. You'll have to call around or do a web search and see what you can find. It may be worth the extra cost to ship the unit someplace if there is no one in your area that can do the work. 'course you have to get a quote for this rebuild (plus any shipping - and insurance!) and compare this to the cost of a new/replacement unit. The unit could be sourced from a Porsche oriented salvage yard, too.

Thanks. any other input from anyone?

You can make it two wheel drive by removing the driveshaft, diff and a couple of other bits. if its the front diff. https://rennlist.com/forums/996-foru...96-to-rwd.html

Gentlemen, Its NOT the front diff. Ive converted 993tt's etc to 2wd 10-12 years ago. Please Im not a Porsche newbe. I asked TWO very spesific questions. I do not need info about that I can ship it to other places or that the Porsche quote might be more expensive etc.... Ive been on this forum since 2004......... 2 questions: Is the rear diff a common failure? Can it be changed? (Of course it can... but is it availiable?) Hope this helps....

answers.. I have not heard of any rear 4S differentials failing since I've been on this forum. I'm sure you can find someone in your part of the world that can rebuild your diff. In the states you would likely send it off to Guard Transmission. As far as availability goes, where have you looked? Any Porsche dismantler nearby?

Quotes source post: 11105681

Oh, you've been on this forum since 2004? Oh, well excuse us, we didn't realize that obviously meant you're an expert on these cars and that you obviously must have converted 993s to RWD before... You did not ask two very specific questions. If you had, every person who answered your initial question would not have immediately assumed you were asking about the front diff and not the rear. ^^^ THOSE are two specific questions. The rear diff on the C4S (and most other 996s) is an open rear diff. The likelihood of one going bad is pretty slim, I've never heard of anyone killing one (granted, I haven't been on this forum since 2004, so I'm no master of the internet). More likely, you have a bad bearing in the transmission, which will basically require a rebuild to fix. It's not super common, but as far as failure modes go on the transmissions in these cars, it's one of the most common.

Sorry, I somehow got the idea you were talking about the front diff. I have nothing to offer other than based on my research before and after I bought my Boxster and my Turbo (and a Cayman somewhere in there too) rear diff issues are rare. But of course if your car has developed a diff issue... For changing it if the basic housing is ok the innards can be replaced. IIRC an aftermarket LSD can even be fitted. Guard Transmission LLC IIRC is the name of at least one company that seems to receive good word of mouth. See here: http://www.guardtransmissionllc.com/...differentials/

Nope, the front diff is not a part of the gearbox.. The reardiff is (thought it was obvious which diff I meant since I mentioned the gearbox) Im as puzzled as you guys are since I dont have there car at home here so I have to take the word from the stealership for granted at the moment. Hence my question if it is a common fault.