squidflakes

Hello, I just bought a 2005 Legacy Wagon and had the rear differential blow out while on the freeway. Like, really blow out. Replacing it looks pretty straight forward but I had a couple of questions about diagnosing the cause after the fact and what, if anything, should be replaced. So first off, has anyone ever had a similar issue? Due to the way the housing cracked I'm guessing that the oil in the diff had never been changed and however many thousands of miles of thermal expansion and wear caused fatigue, which resulted in the gears coming unmeshed, banging around the inside of the housing, and peeling it like a banana. Second, if the CV axels teeth are still ok, can they be reused or should I just plan on replacing them? Third, is there anything to check in the transmission that might have been damaged? Finally, it looks like the CV axels are reasonably easy to get out, but how do you get them back in? Is there a tool for this or is it just tappa tappa tappa until its seated?

Ok, fun update! I probably over did it matching up the sensor wires to the DIY harness work-around but the sensor went in, the car started, the CEL for the sensor went away and I went for a nice drive cycle to try and get this thing to pass emissions. Then the rear diff blew out on the freeway!

I should have the new sensor and the Frankenextender back in today so we'll see if it actually works. And d'oh! Yeah, thank you @Infosecdad for the part diagrams!

Hey Silverton, I'd really appreciate that. I did manage to find the wiring diagrams for the 2005 but they leave a little bit to be desired. If I'm reading these right, it looks like the rear O2 sensor just uses 4 wires, with the two heater wires wrapped together and the signal and ground wires going to a bus or common connector with the other downstream O2 sensors. Putting that together with the parts list that KZJohnny provided it looks like there should be a mini harness and some breakout pigtails, but without that, the set-up I've got should work fine.

Thank you for linking that diagram, I really appreciate it! The sensor I got is the Denso, so should be good there.

Hello, I bought my kid a beat to hell 2005 Legacy Wagon but didn't notice until I had it in my driveway that it is the low emissions variant with the three cats and five O2 sensors. As we were starting it up to take it to get the state inspection done the MIL came on and it started throwing P0420 and P0143 for Bank 1 Sensor 3. On removing the old sensor I ran in to a couple of issues. The first was that the new cable wasn't nearly long enough to reach the connector. Second, the connector is the same six wire layout as the F/A sensors, but the replacement O2 sensor is a 4 wire. Third, I don't know if this is factory or someone at a shop making due, but about half way down there is some sort of 4 wire to 6 wire adapter which is crimped on to the old O2 sensor wires. Does any one know if there is an O2 sensor available with a long enough cable and the 6 pin pigtail? Is that P0143 code for low voltage because a wire is missing? I've attached some pictures for clarity. First is the 6 pin connector, with a scant 5 available pins. Second is the pigtail and the adapter on the other end of that wire. Third is the old O2 sensor and its side of the adapter. I can't imagine that kind of crimp job is from the factory.