I knew this day for me would come sooner or later...
Anyone else have things they dread when it comes to their TR4?
For me this is one thing I've dreaded the most.
I happens from too much pressure building up in the rear differential housing. It would happen to me mostly in the winter months when the diff breather would ice over and the pressure had nowhere to go.
Pull off your diff breather on the rear axle, clean it really well, and then extend it up and into your full door where it will not be exposed to the elements as much with some 5/16ID hose and a few screw clamps.
I seriously need to extend the breather, because the possibility that some ice caused what ended up an extensive repair bill is too much for me. Mine happened last winter, and I noticed it in the spring. I don't want a breather to **** up what is basically now a fully serviced rear axle.
At least replacing the seal and oring is easy and can be done on your own. You can easily do it in two hours taking your time. Just make sure you have the right tools.
Seal puller from harbor freight for like 8 bucks, and a seal driver. Easy enough!