How many quarts of 75W-140 Amsoil do I need for a 04 Cobra with a 8.8 IRS? Do I need a bottle of friction modifier? If so can I use Motorcraft?
I was also unaware of this. Notably, Amsoil's Severe Gear product description states only "AMSOIL Severe Gear is compatible with most limited-slip differentials. If limited-slip differential chatter occurs, add AMSOIL Slip Lock® friction modifier additive," while their Slip Lock description states "AMSOIL Synthetic Gear Lubes do not require the use of this additive. However, not all differentials respond the same and if chatter is noticed, the addition of AMSOIL Slip Lock will eliminate it." It's also interesting that Amsoil's recommendations for my car include the addition of friction modifier.Let's get the debate going. Amsoil Severe Gere 75W-140 already comes with friction modifier in it, 9 times out of 10 you are fine with just the Gear Oil. If you experience chatter you can add some more, doesn't have to be the Amsoil stuff Motorcraft is fine. Start with half the bottle or tube and see if it goes away, if not the whole bottle should make it go away.
I was also unaware of this. Notably, Amsoil's Severe Gear product description states only "AMSOIL Severe Gear is compatible with most limited-slip differentials. If limited-slip differential chatter occurs, add AMSOIL Slip Lock® friction modifier additive," while their Slip Lock description states "AMSOIL Synthetic Gear Lubes do not require the use of this additive. However, not all differentials respond the same and if chatter is noticed, the addition of AMSOIL Slip Lock will eliminate it." It's also interesting that Amsoil's recommendations for my car include the addition of friction modifier.
I'm certainly not arguing with you, but can you point us to an authoritative source for your assertion that Severe Gear "comes with friction modifier in it?"
Interesting so will two quarts be enough then since it calls for 2.1?
I would not be willing to skimp on oil for the rear end. I know what you are thinking when you would need to buy three quarts and hardly even use the third quart.