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Synthetic vs. Non-Synthetic for Differentials

2K views 3 replies 4 participants last post by  VolvoDoc 
#1 ·
So my assumption has always been synthetic trumps non-synthetic for all oils. However I've run across a few things that make me question this for the differentials.

Specifically I believe ECGS recommends non-synthetic diff oil for all of their regeared differentials. Also my new RockJock from Currie has a tag that recommends 85W-140 non-synthetic.

So what's the deal? Why are some manufacturers recommending non-synthetic for their diffs? I'm not an expert on oil by any means, but I assume there must be a good reason for this?
 
#2 ·
It all depends on materials used in the gear boxes like seals and gaskets and metals. Then the different quality and additive packages on each type and weight of oil. Be safe and use only recommended weight and type of oil to prevent unwanted and possibly expensive repairs.
 
#4 ·
Synthetic is conventional oil just with added detergents and friction modifiers. They wont cause a leak and you can switch back and forth all you want. Google it and you'll find all the info regarding what I said.
 
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