You wouldn't believe how long it took to figure out the oil leak our 40 developed, BTW.
We knew it was the remote mounted oil filter.
Problem was, it wasn't just a loose fitting. Turns out that Trans-A-Dapt gave us a defective hose. It's leaking internally to the fitting. It was leaking so much by the time I got home that the only way to figure out it was the hose itself vs the threads was to start the truck with me crawled up under it at the time to watch exactly where the oil was coming from.
Hopefully will have new hoses on monday or tuesday...
And yes, a Diehard Platinum (or any AGM) that is bad may be absolutely scorching hot as an indicator that it's bad. Not real sure how it went bad, but fixed anyway.