Will be fun follow

 

I ended up using Lucas Synthetic 75w-90 and it’s been great. The main reason I was looking at synthetic rather than conventional is because I live somewhere that it’s cold 8 months of the year, and when it’s cold I can feel how sluggish my axles are as opposed to when it’s warm out. Plus with all the added weight from wheels and tires I wanted something that would hold up under extreme conditions. Lucas fits that bill perfectly. I went ahead and refilled the front one too even though they had just done it, and it’s a good thing I did because they didn’t fill it all the way. Opened up the vent and no oil came out. When I pulled the drain pin fluid did come out but it couldn’t have been more than a quart even though he has 2 quarts listed on the parts list from the when the diff was serviced. Not sure what he did with the second quart but it wasn’t in my diff. But now all is well and I’ll continue using Lucas and step the changes up to every 25k since it’s only $45 for three bottles.