I've always use Synchromesh from Autozone. There should be topics here on it.

 

I've heard of several people using Synchromesh but they only had 1 qt of Pennzoil at AutoZone. I use AZ b/c it's within a mile of my house. I'd have to drive 8-10 minutes further for O'Reilly.

 

Tell them to call the other Autozone's for more. They'll have them sent over in 1 day. I like to keep a small stock.

 

Go to the Hyundai dealer. Their Hyundai brand tranny oil is a semi-synthetic GL-4 and the shifts are very smooth.

If you want to know, I used GL-5 and Pennzoil Syncromesh(5w30) in my transmission when I first got it. It was very hard to shift and my gears grineded a lot. It was impossible to shift during cold winter days. IF I were you, I would go to Kia/Hyundai/Mitsubishi or any other dealers that have GL-4 gear oil. ....I guess using it for 3,000 miles ain't bad.