I'm getting ready to service the differentials on my Girlfriend's 2008 Jeep Patriot. The gear oil is supposed to be changed every 60k miles, but at 115K I'm willing to bet it's never been changed before. The owners manual says it takes "Mopart Gear & Axle Lubricant SAE 80W-90 API GL 5 or equivalent nonsynthetic product." Which is strange. I was considering using Mobil 1 or another synthetic like Amsoil, because I don't want to have to service these every 60K, and I figured Synthetic was better.
Anyways, I ordered a gallon of Lucas conventional 80w-90 gear oil because it was the cheapest conventional I could order on Amazon (30$ per gallon), but now I'm having second thoughts. For one I saw Supertech gear oil for 14$ per gallon at walmart. Second, I did a quick search on the forum here, and it doesn't seem that Lucas products are held in high regard.
Is there a reason I shouldn't run Synthetic Gear oil in this differential? Should I cancel my order of Lucas Gear Oil for a different conventional? If you were doing the work what would you put in these differentials?
Anyways, I ordered a gallon of Lucas conventional 80w-90 gear oil because it was the cheapest conventional I could order on Amazon (30$ per gallon), but now I'm having second thoughts. For one I saw Supertech gear oil for 14$ per gallon at walmart. Second, I did a quick search on the forum here, and it doesn't seem that Lucas products are held in high regard.
Is there a reason I shouldn't run Synthetic Gear oil in this differential? Should I cancel my order of Lucas Gear Oil for a different conventional? If you were doing the work what would you put in these differentials?