Maxwell-8 4,277 #1 Posted February 18, 2021 I am fixing some WH trannys and so i will need to fill them back up with some fresh gear oil. The manual says to use GL5 but all the gl 5 around here has a high Sulphur content, which eats up copper and bronze. GL3 doesn't do that but it's a lower quality oil. What should I run? transmissions are from the 300 series Share this post Link to post Share on other sites
ebinmaine 67,628 #2 Posted February 18, 2021 I run the cheapest possible gear oil around 80 or 90 weight. 4 Share this post Link to post Share on other sites
Maxwell-8 4,277 #3 Posted February 18, 2021 2 minutes ago, ebinmaine said: I run the cheapest possible gear oil around 80 or 90 weight. gl3 80w140 whould be alright then. that is the cheapest here i believe. 1 Share this post Link to post Share on other sites
SylvanLakeWH 25,600 #4 Posted February 18, 2021 17 minutes ago, ebinmaine said: I run the cheapest possible gear oil around 80 or 90 weight. At the extreme speeds and temperatures these hot rods run, anything more is overkill... 6 1 Share this post Link to post Share on other sites
Pullstart 62,912 #5 Posted February 19, 2021 Some people have reported running engine oil for higher speed applications with no ill effects either. With that said, any oil is better than low oil in these 1 1 Share this post Link to post Share on other sites
