So ive been reading mixed views on gear oil. im looking to change out the front and rear diff on my 17 4Runner with locking rear diff. now my main concern is to go synthetic or conventional gear oil. ive read that synthetic looses its viscosity at higher temps, and that conventional is an overall better choice for the ring and pinon. dont shoot the messenger just telling you what i have come across. just wanted to get some opinions on you guys think i should run in the 4R. i was originally looking to purchase 75w90 Valvoline Synpower which is on sale at Advance for $10/qt. thanks guys lmk what you think
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