Installing a Dan Cason oil pump pickup extender for a deep oil pan by Richard Cook
I have an M1S, but this should be about the same on most Changs.

One of the things I really wanted on my Chang was a deep pan for more oil to keep it cool. It was a real disappointment to verify that no extension had been made to the oil pump; this brilliant design could mean you blow up with a couple of quarts of cool oil still in your pan. Dan designed a beautifully crafted extension that allows you to pick up and circulate that extra oil, as well as moving the pickup to a more effective location and adding a screen that might actually screen something. This version requires removing the pan, cutting a lock wire, and removing the four bolts that hold the pump. Dan is currently designing a new version that may just require removing two bolts and seal with an O ring. Dan includes some basic directions, what to look for, and his number if you have a problem. He also includes replacement bolts.

You will need

  • A reasonable amount of mechanical skill.
  • A pan gasket or material to make one
  • A metric socket set, I like to use quarter inch on this stuff, and the pan bolts are easy with a nutdriver
  • Sidecutters
  • Allen wrenches, you may need to cut one shorter
  • Sealer
  • Red Loctite
  • Permatex
  • Cleaning fluid of some kind to clean up your pan and a parts brush is nice.
  • Jack up the bike and block it up.
  • Remove the oil pan bolts, on my bike these were 8 mm, but Changs tend to have a sense of humor about bolt sizes.
  • The pan may be glued on the first time and require a bit of force, don’t damage the edges, work a putty knife in slowly if you must. I had had mine off before so the gasket was glued to the pan side only, came right off and was reusable.
  • Locate and remove the cover with holes on the bottom of the oil pump, this is on the bulge that is on the non sidecar side of the bike.
  • You will see a safety wire between two bolts, remove this with your side cutters.
  • Remove the cover.
  • There are four bolts, two small ones hold the pump cover on, and two bolts hold the pump to the engine.
  • First take a straight edge and measure how far your oil pump cover sticks up over the edge of the surrounding casting. Mine did not. Changs may not have had the pump mount set uniformly during machining, lucky me, mine was down. This meant the extender would not clear the casting when fitted. Dan to the rescue, he made me a spacer and had it in the mail in a couple of days.
  • If you have the older Dan Cason extender version, next remove the four screws that hold the pump together and on the engine. Note that I have used a 10mm box open wrench held on by a nearby pan screw to keep my pump from dropping off the drive while I measure and work. The loose pump gear could also drop in the dirt if not retained. This job would be very easy with engine upside down, a bit tougher in the bike.
  • The oil pump may or may not have a fragile gasket. Mine broke when I remover the cover. After cleaning up I used a straight edge and a small feeler gauge to determine I did not need the gasket.
  • With the pump cover off you may note a few things. I had wear on the cover and I removed this by flattening it on a marble surface with 1000 grit sand paper. One person reported his Chang oil pump cover had the hole in the wrong spot and had to Dremel his. My hole was perfect, Dan has checked three pumps for hole location, but you know Changs. I did find my cover top was uneven so I did not trust it to seal to the nice spacer and extender. I double checked with a straightedge that the extender with pickup still cleared the pan. Chang pans might also be different brands and depths so it would be good to make sure before you bolt it up and cuss yourself, not that any of us would ever do that. I used a thin circle of Permatex around each hole in top, spacer, and extender. Keep the Permatex back far enough so it can’t get in the hole and block oil passages. I kept it back as far as possible to still seal the hole. Keep in mind Dan does not approve of Permatex here as sloppy work could get it into the pump.
  • I set the three parts up on the bench with the two large screws and the slightly difficult small screw already installed. If necessary you can use a rubber band to hold the bolts in and cut it later. The small oil pump cap allen screw just cleared to install. The thin layer of Permatex tends to hold the three parts themselves in alignment.
  • Make sure everything is clean and reinstall the cover and pickup, I used Red Locktite on the bolts, and if you are anal you can look up bolt size and torque it. I had to shorten one allen wrench to clear.
  • Reinstall the pan, you did check for clearance didn’t you? Hopefully here is not a half inch gap between pan and engine. I use a spot of silicone sealer on the side of each pan screw, a nut driver gets them just about right.
  • Fill with oil and test it, idle for a while to make sure you got it right before heading out on the highway.