I'm getting ready to change my IRS diff cover with the new Ford racing one, I just purchased the 75W140 royal purple gear oil with friction modifier, Does Anybody know how many courts the IRS needs And do I need to add additional friction modifier?
OK thanks I will be running the stock differential I'm just upgrading the dif cover so is the additional friction modifier needed?The friction modifier question depends on what kind of differential you will be running.
When filling with the FRPP cover, just continue to fill until it starts to come out of the fill hole. The capacity should be similar to stock.
Best of luck with it! It's a nice upgrade.
OK thanks I will be running the stock differential I'm just upgrading the dif cover so is the additional friction modifier needed?
OK thanks I will be running the stock differential I'm just upgrading the dif cover so is the additional friction modifier needed?
Okay thanksIt won't hurt to put more friction modifier in even if they claim to have it added. According to Ford manual fill is 1.23-1.37 L [2.6-2.9 pints] not including the friction modifier [4 oz]. The manual also says to fill until 0.25" below the fill plug.