Jump to content

Server Lease Renewal/Software Licenses

Our yearly server lease, software licenses, as well as hardware operating costs, WERE due Dec 4th, 2022. Our current donations have fallen far short of the funds we need to renew. Please remember the RennTech.org community is Member supported so please consider a donation to help...  THANK YOU!

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

C4S front differential/viscous coupling

Recommended Posts

Just today, I noticed a strange noise coming from the front of my C4S. It sounded a little like a slipping belt - sort of a high pitched squealing. It only happnes under very specific circumstances, and it's intermittent. I've been able to replicate it a few times, but not consistently. The noise happens when I'm coasting down hill, in gear. I've only heard it in 3rd gear and 4th gear at this point. Giving the car gas when the noise is heard makes it stop entirely.

I'm beginning to wonder if the viscous coupling is "slipping", or if perhaps there's some other issue with the front differential. I had my differential fluid changed at the 90,000 mile service a few years ago, but it hasn't had any service or issues other than that.

Any thoughts? Does this sound like a differential or viscous coupling issue? I can already see dollar signs floating in front of my face...

I'll be taking the car to my mechanic to have it checked out, but I'd love to hear some opinions or hear about similar experiences and solutions.


Link to comment
Share on other sites

Maybe this is something else... I'm not sure. I've read several threads about the AOS making a squealing noise when failing. This noise does sound like it's coming from the front of the vehicle though, not the rear. I can't feel anything in the suspension or steering, I just hear the noise. It's strange...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.