Hi Scotty I have I been watching your videos on YouTube I really enjoy the content. I wanted to ask you a question and what are your thoughts on the matter. I recently opened up my rear differential on my 2000 f150 so I could change a wheel bearing and seal. what I wanted to know was do I need to add friction additive if the oil I used for the rear diff says it has it in it. the oil was royal purple gear oil. what are your thoughts on the matter?
2000 f150 single cab short box xlt sport 5.4 v8
If the gear oil you're using meets Ford's specifications there would be no need for additives.
The Haynes Manual I have just says SAE 75-90 GL5 gear lube plus add 4 ounces of friction modifier to 8.8 and 9.75 inch rear ends. The side of the royal purple gear lube bottle says SAE 75-90 GL5 with friction modifier in it already. So idk do i trust this stuff or should i add to it, or do I bring it it back find a gear lube with nothing in it and add the 4 ounces of friction modifier I need.
The Haynes manual might or might not be correct. What does your Ford factory owner or service manual say to use?
The Haynes manual might or might not be correct. What does your Ford factory owner or service manual say to use?
Bingo. Find out which axle option you have. Take the purple people eater back.
Pages 249 to 251: https://www.ford.com/support/vehicle/f150/2000/owner-manuals/
