Re: Synthetic 90 SAE

Posted by FirstEliminator On 2024/7/18 13:47:32

Starting with I've never had a Packard rear axle apart, but I do run a transmission shop that does a fair amount of axle work. As long as there isn't brass, a GL-5 75-140 syn would work well. The synthetic seems a bit more resilient to heat and breaking down over time. Plus, it has better cold weather properties which are a moot point with most, if not all Packards in our current era. The GL-5 spec has an additive in it that will attack brass or bronze over time. A GL-4 spec gear oil is safe for brass.

Mark
Berkshire Transmissions
North Adams, Massachusetts