[Vwdiesel] Oil recommendations?

[Roger Brown]

Shawn Wright wrote:
> I notice you're recommending the straight GL-4 lube, not the AGL or AGR which is
> GL2 - 5 rated, or the Series 2000 TGR which is also GL 2-5.
> When I went to replace the oil in my Vanagon trans (also calls for GL-4) I called
> Amsoil asking for the best oil for this application and they said the TGR was it. I was
> worried about the GL-5 rating, but they said they do not use Sulphur like most other
> GL-5 oils, so it is syncro safe. The shifting is fairly good, but not as good as the
> Redline MTL I had in it before. (I've since learned I should have used MT90 for the
> Vanagon). My main concern at the time was protecting the R&P in the Vanagon
> trans, which had failed with Redline MTL in it, although it was probably already nearly
> worn out before I added the MTL.
>
> How do you feel the AGT compares with Redline MTL? I'm going to need some for
> my Jetta soon...

I find a single grade GL-4 oil is the best for manual transmissions, that what is was designed for.  Anything higher than GL-4
is designed to be slipprier for use in helical (hypoid) gear applications.  Transmissions have straight and bevel cut gears, so
the EP additives are not needed (this is usually where the sulphur comes in that can attack the yellow metal parts).  The
slippriness is what makes the synchros work slower, since they slide over each other longer before matching speeds.  A GL-4 oil
has the proper friction coefficients to allow the synchros to spin up faster and less time spent sliding past each other is less
wear.

--
    Roger