<VV> Finding manual transmission oil locally?

Bryan Blackwell bryan at skiblack.com
Sun Jun 30 09:43:20 EDT 2019

Corvairs share the lubricant between the trans and diff.  You *cannot* use ATF, and you *should not* use GL5.  I'd suggest finding a place that carries GL4, pretty sure Amsoil has one that meets the specs, or just order the stuff, there are quite a few vendors who carry Amsoil products.


> On Jun 30, 2019, at 8:00 AM, Hugo Miller via VirtualVairs <virtualvairs at corvair.org> wrote:
> As a general rule, synchromesh transmissions run best on ATF. What you want to avoid is hypoid oil, as this will allow the synchro cones to slip & slide without biting. I have known commercial ZF transmissions become almost underiveable when filled with hypoid oil.
> The problem is that in the good old days, we had hypoid gear oils and we had EP (extreme pressure) gear oils. So you had EP 90, which was good for synchro transmissions, and Hypoid 90, which was not. The two were quite different.
> But today, through the magic of modern chemistry, we see EP/hypoid oils, which serve both functions. I would avoid these and use ATF or EP 90 if you can find it.
> I'm not up to speed with the GL numbers - Google will tell you more than I can. Just steer clear of anything with 'hypoid' on the label.
> On 2019-06-30 12:11, John Gull via VirtualVairs wrote:
>> Well not having any luck finding 75w90 gl4 gear oil for my 65 4speed
>> tranny! I can find gl5 oil but according to Richard Widman website it
>> is not recommended to use. Any suggestions where to find locally will
>> be helpful. Thanks John Gull in Asheville NC

More information about the VirtualVairs mailing list