<VV> Tranny and rear axle oil

[Vairtec Corp]

This thread is starting to wear me out.

It's easy, really.

What is needed for stick-shift Corvair transmissions is Service GL-4, 
with no mention of GL-5 on the label.  Even if the label includes GL-4, 
if it also includes GL-5 don't use it.

This is true for all manual-transmission Corvairs. Powerglide-equipped 
vehicles can use the newer GL-4/GL-5 products because the differential 
lube is not shared with the transmission.

Here in my New Jersey climate, SAE 80W-90 is the best readily-available 
viscosity.  But there are synthetic products available with a SAE 75W-90 
rating, and these synthetics are generally acceptable.  But 
non-synthetic products with a 75W-90 rating are too light for our Corvairs.

Also available is 85W-90, but this is considerably thicker when cold and 
is not recommended.

I am not a oil expert.  But Richard Widman is and I took this 
information from his writings on the topic.  See it here: 
http://www.widman.biz/uploads/Transaxle_oil.pdf

The key point is, use 80W-90, Service GL-4 that has no reference to GL-5 
on the label.

--Bob