75W90

75W140

80W90

85W140

SAE 90

                 This is the weight that max-gear has available.... What
is recommended here?

Mike S wrote:

> At 01:04 AM 3/12/2007, Geza Polony wrote...
>
>> when cold. He tells me to change the Redline to dino GL-4. Problem is,
>> GL-4
>> is hard to get. The Royal Purple site says their GL-5 won't damage
>> synchro
>> rings, and there are plenty who swear by Redline. I know this has been
>> a
>> subject of discussion in the past and have searched the archives, even
>> finding another reference to Ron in 2003 who was then giving thumbs up
>> to
>> GL-5.
>
>
> If you use a GL-5, it should also carry the MT-1 rating. The reason for
> this is that the easiest way to meet the high pressure lubrication
> requirements of GL-5 is to use a sulphur based compound (like
> molybdenum disulfide). Sulphur compounds eat yellow metals, like used
> in synchro rings. The GL-5 spec does not require a test for stability
> in the presence of copper and copper alloys.
>
> GL-4 is good because it requires a ASTM D-130 copper strip corrosion
> test.
>
> MT-1 (and MIL-PRF-2105E & SAE J2360) also require a D-130 test. If
> you're going to use a GL-5, it should also carry one of these ratings.
> Synthetics often carry these ratings, since they usually avoid the use
> of sulphurous HP lubricants.
>
> ASTM D-130 is designed to assess the relative degree of corrosivity of
> the sulphur compounds contained in a petroleum product. The test is
> carried out by immersing a polished copper strip in a given quantity of
> sample, heating at a temperature and for a time characteristic of the
> material and comparing the copper strip after it has been washed and
> dried with the ASTM Copper Strip Corrosion Standards.
>
>