to heck with the hammer routine for that ring. Go down to your local good hardware store and buy a metal plumbers wrench for a 2-1/2 inch nut. Cut off the tips of the wrench so you have square ends. you will find that the wrench is a perfect fit to undo that ring (place it verticaly, it has a deep enough throat that it will clear all the wires and pipes). Use a pair of vise grips to hold the top of the wrench and turn it. Usually, those wrenchs are double ended. This allows you to put a cheater bar on the end and get good leverage.

I'd suggest using PB Blaster rather than WE-40. And I second the suggestion to give the stuff time to do its work. In terms of loosening the ring, I used a 1" X 1" stick of wood to rest on the knobs and struck the end of the wood with a hammer. No sparks, and a bit gentler on the ring. Try to wipe up as much crud as you can before you actually begin to take things out of the tank. Oh -- and get yourself a new ring.

Rob

As I sent out to someone else today, I just did mine last weekend. '89 240 sedan. THat 'crown nut' looked scary. But I did as you . scraped and claened around it vaccuumed all the dust and stones up and had at it. I did what Larry recommended, I WD-40'd it then ate dinner. After that the WD worked it's way in a bit. I tapped on different bumps on that crown to loosen it. If you just smack on one, it actually binds it a bit. So tap on as many of those bumps as you can reach. IT MAKES A DIFFERENCE. Same for putting it back together.

As I sent out to someone else today, I just did mine last weekend. '89 240 sedan. THat 'crown nut' looked scary. But I did as you . scraped and claened around it vaccuumed all the dust and stones up and had at it. I did what Larry recommended, I WD-40'd it then ate dinner.

/// You didn't say if it now runs. I often patch a repair to stall until a better time to work on it. (My own) If the sock is bad you are pumping potential trash to the main pump, but!, you have been doing that already. I would spray WD40 on the area and test the ring. Stop is the ring is not solid and able to turn. Leave it there and start loking for a good used complete tank. You can repair, and coat the second tank with the polyester tank saver. I am not familiar with all tanks and the fit to your 85. Some one else will know. If your wrecker yard has a cross reference you can see which years are exactly the same.

Remember you would not have even looked for the bad ground if the system was working. You would still be driving with no concern or indication of trouble if it hadn't stopped. Coin toss your call.

I believe in fixing it all when I start. I have some hints if you decide to remove and reinstall the tank.