75W -vs- 85W Gear Lube

[EugeneTheJeep]

I'm going to change my diff oil tomorrow and all I could find at the local autoparts stores were quarts of 85W gear lube and I know the libbys call for a 75W lube. Long story short is it a bad idea to use the 85W lube, could it damage anything and whats the real difference between 75 & 85W oil.
Thanks !!

 

[tgh117]

It won't hurt anything, its just a tad bit thicker, which could result in a loss of maybe a 1/8th of a mile per gallon of fuel or something, but wouldn't be much at all. You will be fine with that.