I brought up this subject as I was about to go through my 365 transaxle and started to look into recommended oils. I'm a big fan of Redline and almost use it exclusively in my race cars and vintage cars like most of the people on this site, especially in our Elans as it does make a difference. But on my vintage Porsches, the community believes that the Swepco 210 is the oil of choice. And it is a synthetic hypoid oil. Needless to say, with the limited use that these cars now have to undergo, I think the Redline would be fine, and the points everybody makes does sound reasonable. But a few things are still sticking in my head:
1) Redline warns that the MTL and MT90 oils are not to be used with hypoid gears.
2) A non marque gearbox only forum indicates that while it was ok in the past to use Redline MTL and MT90 in transaxles, it is no longer recommended as they removed the zinc from the formulation and it was found to cause damage to the ring gear and pinion. I have to assume the zinc allowed the gears to swipe easier.
3) Redline recommends the use of their 75W90NS which is a Hypoid oil for the Renault Transaxle and not the MTL or MT90.
4) Factory specs is for a Hypoid oil.
So now with this said, I fully understand and agree that the Renault transaxle has less of a swipe across the gears. But it still does have some. And again, with the miles put on these cars it most likely does not matter, maybe. But since the Porsche community has been using the Swepco 210 product in their transaxles for ages, and the fact that it is a hypoid oil, I think the safer bet would be to just use the Swepco product or the Redline 75W90NS, especially with the change in formulation with the Redline MT products. But as of this point, I think I will be using the Swepco product as it is in my vintage 911's and later Porsches. Just saying. Thanks Allan