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57rookie · 03-27-2018, 01:23 PM

So went shopping today and I can't find 85/90 GL4 - not available in my area....
Closest thing I can find is 80/90 that is GL4/5 compatible but I don't want to use anything with a GL5 on the label after reading the above info about bronze syncros.....
I did find a GM spec Penzoil for older manual trannies - it was 80W90 BUT it was GL3 spec- would this work???
Never thought looking for a GL4 spec gear oil would be so difficult....

03-27-2018, 01:23 PM	#9
57rookie Registered User Join Date: Jul 2011 Location: Calgary, Alberta Posts: 153	Re: What gear oil for 4 spd manual So went shopping today and I can't find 85/90 GL4 - not available in my area.... Closest thing I can find is 80/90 that is GL4/5 compatible but I don't want to use anything with a GL5 on the label after reading the above info about bronze syncros..... I did find a GM spec Penzoil for older manual trannies - it was 80W90 BUT it was GL3 spec- would this work??? Never thought looking for a GL4 spec gear oil would be so difficult....