The '07s - '09s do wine in 1st and 5th because of the way the gears are cut. They are the 'working' gears, the ones you use when pulling away, passing etc and were cut for strength. A good gear lube will take away most of the wine and just leave enough so you can tell what gear you are in. The wine is normal, not an issue although a lot of people thought it was a defect or problem.

 

I think the way this goes is the 09 gear ratio was changed so 6th gear was more usable at lower RPM'S, but had a whining noise in 5th gear. In 2010 the MoCo put a Helical cut 5th gear in to fix the whine. Mine did whine a little until I went to Redline Shockproof gear oil in the tranny.

 

Dealer probably used Syn3. I used to get Neutral Rollover noise before I switched to Torco gear oil at the 1k. I change my oil pretty often (every 3K), so I tend to stay away from synthetics.

 

Redline shockproof heavy is 100% synthetic, is red colored, and pours like blood.....THICK!

 

New Helical-Cut 5th Gear
For me, 5th has always "sounded" differently from the other gears. Talking to others I have come to the conclusion that this is normal for 5th (mine is a 09 w/6 speed). Interesting that it should sound different after the 1st service. Wonder if it could be attributed to the type (synthetic or not) of lubricant used?