First year with T when I make a sharp turn. The rear end makes a growling noise going straight is ok
Jack up your rear axle and see how much movement you can get by pushing the rear wheels in and out. Could be the begining of the babbit thrust washers failing. Report back with what you find.
Mine did same thing two years ago. It was the thrust washers, there were none. Had to install the bronze ones.
The first pictures show a symptom that can happen when the old babbitt thrust washers go. The axle shifts inward and the brake is destroyed by the turning hub nuts and bolts.
The last two pictures show the chunky silvery oil made by disintegrated thrust washers, and the remains of those washers.
When you take the plug out of the rear end and stick your finger in, and it comes out with chunky oil on it, that tells you exactly what's going on. If it comes out with clean oil, that tells you it might be OK. The growling noise suggests otherwise. The only way to know for sure is to open it up and look inside.
I suppose that there is another possibility...
There is that fiber disk that sits in between the axles in the gear housing. If it's worn or missing all together, then the axles can slide in and out around turns, and then the axle gears can grind against the spider gears. I'm just theorizing here, and I don't know how pronounced the symptoms would be.
In the end, babbitt thrust washers are always a likely suspect (and are almost always the problem) when it comes to almost any differential problem! I'm picky about this kind of stuff, so I always err on the safe side and take the differential apart. Last time, it took me just under an hour to remove one and open it up, and that was working by myself!
I've had the pleasure of disassembling several Model T axles. Not one had a fiber disk in it when it was taken apart. My opinion, the fiber washers don't last long.
I started using a brass washer in place of the fiber disk. I think it might be there next time someone takes the differential apart.