Yesterday I found the culprit for my leaky differential. Those cracks are definitely not supposed to be there! Getting the axle out of the diff was pretty easy as well as getting the new seal in. But putting everything back in took a bit of work but still didnt take too long. I put in the new Redline Gl-5 spec 75w-90 fluid and then moved onto swapping the gear oil in the transmission. Well the fill plug for that managed to stump me for well over an hour!
Some bright minded ugga dugga fiend must have driven the plug all the way into the hole because it was damn near impossible to get out. Those threads are not supposed to be that f’d up nor is it supposed to be so rounded. The fact that it was a square bolt (supposed to be that way for some god forsaken reason) made it that much harder to get a hold of the damn thing. But the real culprit was just threading it in all the way. That plug only needs to go in about 3/4 of the way to be secure. Not quite sure why but it was ALL the way in so my life was hell just getting it loose with vice grips. Eventually I got it out though and evacuated the nice brown gross old fluid in there. Redline GL-4 spec MT-90 swapped in and now the car shifts even nicer! I still have to put in turret fluid but this is already leagues better than where it started. I am sure once I really test it out with some heat in the trans, then it will shine even more. From what I read MT-90 is not really ideal for primarily street driven miatas because it needs heat to really work. But on track it should lead to much smoother shifting for sure.
Due to the struggles with the fill plug, I didnt get around to swapping on my other midpipe that I wanted to do nor get started on freeing my screwed up caliper. But at least I have made some progress! Next up will be fixing said caliper, replacing rotors, putting in the track pads, fuel pump replacement (need to order an OEM pump), and then radiator upgrade. The to-do list has actually gotten longer but that tends to be how those work anyways.
At least the plus side of that maintenance job taking so long was that the hike I did after got me a really nice sunset view instead of just being a grueling climb for a quick workout.