I used royal purple gear oil, don't have to add limited slip additive since it's already in it. I purchased gear oil and had firestone install front and rear for 75 bucks or do it yourself.

I didn't notice any difference in coasting when I lifted and added wheels. But when I did my differential gear change, it was crazy how much faster and further I coasted. Almost got into a couple accidents cause of it.

 

Well I just did the front and rear diff... Holy **** that pas a PITA.... Ford dropped the ball there should have been drain plugs on both... Transmission fluid change is next... Have only driven like 2 miles since changing the fluids but I definelty notice an improvement!

 

Hmm.. Looks like I need to change my diff fluid pretty quick. I was planning on it last summer but never got around to it. I didn't think you would feel the difference. Good to know.

I did just change my fuel filter and my truck feels much better after that. The amount of brown crap that was coming out the old filter was crazy. I'll be changing my fuel filter more often now.

 

Yeah I did the fuel filter and plugs about 3 weeks ago and it helped and then the diff fluid I did yesterday was definitely noticeable. Next I'm thinking about doing the coil packs... Just haven't decided yet