No magic oil will stop the 3-4 slider hub from cracking, the 4th gear from
breaking, the main ball bearing from pounding loose in the case, the Syncro
granny gear housing from cracking, the 1-2 shift lever from falling off the
pin, etc. The only gears that usually wear that matter are the ring and
pinion sets and I like to use an oil that will protect them the best. GL-5
for me and if I am increasing horsepower or tire size a heavier
viscosity-maybe.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Tom Carchrae
Sent: Wednesday, August 29, 2012 9:01 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Gear box oil - Redline MT90 or Swepco ?

I have to ask just how bad is it to use the much more commonly available SAE
80W-90 in there?  Or in other words, what is the benefit of these
harder-to-find oils?

Easier shifting, ok, got that.  Cooler temperatures?  Not clear if there is
any benefit from these alternatives - or is there?  Will they make the
transmission last another 200k?  Should I throw the giant jug of 80W-90 away
or use it to flush the transmission?

Mostly I'm interested in knowing why this is a big deal.  It certainly seems
important to some - I just want in on why.  Is it just you want the best of
the best, or is it really that the common oil is crap.  What do I get from
better oil?

Thanks for any illumination.

Tom