Quote:
Originally posted by hoover
This Amsoil seems great stuff, but I'm hearing stories of synthetic not too good for brass/bronze bearings in g/box. Others say no problem. Anyone got the true facts?
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Yes indeed, I have the answer for sure.
First of all, it's the GL rating that has to do with "yellow metals" in the gearbox. Normal "dino" gear lubes get much hotter than synthetic, and therefore they must take care to keep the sulphur in the oil from reacting with the yellow metal and causing corrosion. This was apparently done with special blends and additives.
Synthetic gear lube runs so much cooler that this is generally not a problem in the first place.
You will note, Amsoil Series 2000 75W90 has a "GL" rating that includes the Porsche requirement, and exceeds the Porsche requirement. You will also note, if you look far enough into the Mobil-1 gear lube, that it does not meet the Porsche requirement, however, since it is a cool running synthetic it is "probably" ok to use, but Amsoil clearly has the advantage with their gear lube. I have not compared Amsoil to Red Line, which I understand has a good product but the Series 2000 is one heck of a good product, and you have absolutely NO WORRY about anything in a Porsche transaxle if you're using that product. I was amazed at the difference it made in my high milage 1984 944, made it quiet and also shift much better.
Check this link for Amsoil. You will see it's rated from GL2 through GL5. Compare any other gear lube to this spec, if it's better, it must be one heck of a fantastic product.
http://www.amsoil.com/products/tgr.html
If you take this advice, then you may also want to take the advice I offer about K&N air filters, which apparently only on this forum, seem to have some fans. They're junk, offer no improvement in milage or power, and admit way too much microscopic silica, thereby accelerating the wear between rings and cylinder walls. If you don't take the advice on K&N, then you may not want to take the advice I offer on the gear lube either, because I may not have a clue about what I'm talking about. lol
regards, P