I was reading a bottle of that Lucas Oil Additive. You know the stuff they have in that little demo at NAPA with the plastic gears so you can see how it makes your motor oil sticky? Anyway the bottle claimed it could be used undiluted in diffs and manual trannys. Has anyone tried this?

 

The reason I ask is I bought my '84 GL with a manual transaxle about 20,000 miles ago and I figure it is time I changed out the diff and transaxle fluids. What would you recommend as the best fluid for these applications?

I would just put in some redline gear oil, that lucas stuff is damn good but a synthetic gear oil would be my rec.

 

If you want to play around buy the lucas made for motor oil, I almost swear by it!