Best Transmission oil

I am changing the oil in the transmission and want to know if one brand or weight is better than another. Thanks.

Chuck,
This may help you decide.
http://www.aircooled.net/gnrlsite/resource/articles/synthoil.htm

In two of my VW based cars:
I am running Mobil synthetic in one of my VW Transaxles and after reading the article from aircooled.net, I just put Amzoil in my other VW transaxle.
I can't really say I noticed any difference in perfomance, or temp. however, I have no specs. for comparison, as I don't have any monotoring devices installed.
Greg B

https://www.speedsterowners.com/knowledge/article.asp?id=197

Great information, I have it down to 2 brands, but is there a difference in the weight of the oils, or is it just gear lube.

It's called hypoid gear oil. With regards to weight stick with the specifications as per the VW Service Manual (I believe 75W) complying with GL-3 (I believe at this time products complying with up to GL-5 are being offered; of course those comply with all previous standards). The general consensus in this instance is that synthetic gear oil is better; as opposed to the subject of motor oil for the air cooled engine in which there is a huge debate over synthetic vs. dino.

Can you mix synthetic oil with what's left of the regular oil in the tranny after it is drained?

Chuck; if you remove both drain plugs under the transaxle you should be able to drain most of it. It won't be a problem if some synthetic gets mixed with the regular gear oil but as I said, if you take out both drain plugs you'll be fine.