I have a problem with my 2008 GT 5-speed. When I make tight turns I get a "moan" from the backend. I still have about 5K left of my warrantee so I took it in. They jacked it up added some friction modifier to the rear diff. Now the noise is gone (for now). So my question is this--Is this a fix or did they just put a band-aid on a bigger problem? I hope I didn't leave anything out. Thanks!

 

well i did a search on the subject and found some info, but if anyone has anything to add please feel free!

 

I had the same noise on my 05 GT and I just added the bottle of friction modifier myself. It should be a permanent fix. The friction modifier wouldn't be necessary if the friction discs in the diff weren't so tight fitting. In some cases adding the friction modifier isn't enough to quiet the diff. In these cases, Ford installs thinner/weaker friction discs, which I was happy to avoid. Suprisingly, the diff in my 08 Shelby GT has never made any noise.

 

Hopefully your search results mentioned adding a bottle of XL3 friction modifier from Ford. You can get a bottle for a few bucks at your Ford dealer, and if you can get under the car (safely) you can add it yourself in just a few minutes. Problem fixed.

 

Thanks for the input guys. The tech at ford put the FM in the case and I haven't had a peep. Seems to have fixed it!