UPDATE: Diff leak/Fluids disaster 2011 tacoma 6600 miles
Kinda long but thorough.
So I went back under the truck to get a better look from yesterday. I brake cleaned the diff after I swapped the fluid. It wasnt leaking where the driveshaft goes in to the carrier assembly. The leak was where the carrier assembly joins the differential at the carrier seal.
There are 11 nuts that screw on around the perimeter of the carrier assembly to bolt it to the differential, with a gasket in between. I looked up the torque specs of these 11 nuts and found them to be 18 ft/lbs and I checked them to see if they were tight. ALL of them needed to be re-torqued back up to 18 and 1 nut right where the leak is happening wasn't even tight. Literally I could spin it off with my fingers. The one on the direct opposite side of the loose one was ALSO free spinning.
So out of 11 nuts 2 where free spinning and 11 had to be re-torqued. Just for shits I made them all 20 ft/lbs for a little piece of mind. I mean seriously Toyota? 6600 miles and the truck is coming apart? Once again I brake cleaned everything and took it for a ride. After 10 miles of "spirited" driving I came home and it looked dry still. So tomorrow morning ill check back and see whats good.
Also, not sure why the fluid came out so absolutely disgusting. I swapped them all after seeing the diff fluid. Every BMW M car I get in for the 1200mile break-in period service at the dealer we swap fluids in the trans, diff, and engine oil. ALL the fluids come out looking brand new like they went in and the drain plug has barely anything on it. The engine oil has a slight used color by not at all "dirty".
If Toyota says drive train fluid swap at 30K then why is it at 6600 the rear diff looked TERRIBLE black and the drain plug had flaked and A LOT of metallic fine paste metals. It was so gunky and sludge like. The 6spd trans fluid came out almost new looking and the magnet plug had enough metal flakes to cover the tip. Not bad honestly. The transfer case was excellent. I had my engine oil and filter changed at the dealer but I did it again anyways. It looked used but not disgusting I really could have kept it. Only thing I didnt do yet was the front diff. Ill let you guys know how that goes after autozone
restocks their Mobil 1 75w-90. I bought the last six. I had a bottle at home too.
After this synthetic fluid conversion, if you will. The truck seems a little happier I guess. I do say the shifting was a little improved. The feedback from the stick is much better. Engine still ticks gotta love that 4.0. No noticeable difference in the diff after fluid change.
So after all this hopefully I gain 1 or 2 MPG and at least I know its all clean now.