Size of 5 Spd trans filler hex opening?

[canada karl]

Anyone know the size of the side mounted filler hex head openining on the 5 spd? What is the recommended oil for same if you don't go with synthetic? CK

[Tomslide]

17mm. I can't make a non synthetic gear oil suggestion because I don't suggest it. It's only a few dollars more every 15k miles. You have an e12. Buy synthetic gear oil. Redline MTL seems to be the best in my experience.

[Mike W.]

Recommended non synthetic is an 80WT GL4 gear oil. Alternatively motor oil, I've used straight 50 or 60 in the past. The common 90WT or 75-90 gear oil is a GL5, which is a much stickier oil designed for hypoid drives and leads to poor cold shifting as it's so sticky the synchros don't work right.

I have had 2 different G265 trannys get noisy while using MTL so I no longer recommend it. Now it's always possible it was just due to 200K+ miles, but I use other oils now.

[canada karl]

n/m