My question is the same...but not yet answered:

Could be a money grab by ECS/Turner, but they look to add quite a bit of items in their diff servicing kits (https://www.ecstuning.com/b-assemble...3117525064kt2/). I have not yet tackled my diffs and transfer case, and their procedure that is linked from the kit is too universal to be helpful. Can anyone advise for a 2007 4.8i? If all this other stuff is not needed - I would just get appropriate fluid, magnetic plugs and go for a drain&fill. TIA.

I've done both diffs and transfer case. Very easy to do

Part Number Part Name
07-51-2-293-972 Synthetic Gear Oil Saf-Xo 832514
33-11-7-525-064 Drain Plug
83-22-2-409-710 Dtf 1 832514

Thanks CleanIsFAST!

:thumbup: I have a couple pictures in my journal on xbimmers: https://www.xbimmers.com/forums/show....php?t=1715451

I think post#7 for rear diff and post #10 for front diff, fuel filter, TC

More thanks for the link. I reviewed the whole journal and your system for catch-up maintenance is very similar to mine. Where I’m a little bit stuck is I seem to be getting under 10mpg on my 2007 4.8i after the first 200mi of ownership. Knowing nothing that might not be offensive to me...but my 6mo older 4.8is e53 gets 15-20mpg, no problem....and heavier, I think. My tires are topped up, fresh oil change, clean air filters. I went to search out the fuel filter yesterday and could not seem to find an external one. Lastly, I’ll do spark plugs/coils when I do these diffs, TC, brake, tranny, and coolant drain/refills over the next month...I’ll be even more concerned about the fuel economy if plugs don’t help. Any ideas?

Yeah under 10mpg seems really low. My father is original owner of his 2007 E70 4.8i and still has it with over a 100k. I don't think his was ever that low. Granted it is a V8 but like you said, the E53's weren't that bad. And I've had two E53 iS models as well. I have the 35d so my mpg is a lot higher. avg 26-30mpg on highway and 19-21 city.

Plugs should help a bit, may want to check the ignition coils as well.

Will do. I considered diesel but when this one came up for sale locally, I could not resist:

www.woodhouse.com/vehicles/370916

They wanted 25% over book, talked them down to 10% over book...pending a/c fix. They replaced the blower motor, then the a/c pressure switch, THEN the compressor, finally the junction box. That fixed it, but in the mean time they put a nail in tire and popped a rear airspring. 5 times they failed to make delivery!!!...had whole deal unwound, paid of loan with $45 in interest accrued. Then, after scouring the US and only finding only ONE truck with this beloved interior for sale (private seller in would not respond)...I nudged the wife to reconsider this one after $4200 worth of work had just been invested into it by dealer (full HVAC and airbag). I hope it’s a good get, but time will tell! I’ll report back after getting plugs/coils knocked out!

Nice find. Ultra rare ventilated seats as well. They sell that tow hitch trim piece separately if you wanted to refresh that.

Need to be careful about Valve Stem Seals on those. Similar to 4.8iS, I think it's the same motor (early gen 4.8i E70s). My father had to have his VSS replaced recently around 110k miles.

Could be running lean as well and dumping gas hence the low mpg.

Sorry to steering this thread of tracks!