I JUST GOT MY FIRST PLYMOUTH, A 39 ROADKING 2 DR SDN. I CAN'T FIND A TRACE OF AN OIL FILTER, I'M GUESSING THAT IT WAS PLUGED OFF. I CHANGED THE OIL OF 3-1/2 OTS. BLACK OIL, NO SLUDGE OR METAL WERE FOUND IN THE BUCKET LEFT OVER NITE. I ADDED 5QTS. 10-40 AND THE GAGE JUMPED UP FROM 30-35LBS TO 40-45 LBS. I DRAINED ABOUT A QUART AFTER RUNNING FOR 45 MIN. AND IT WAS NEAR CLEAR! SURE, I NEED A FILTER BUT HOW SHOULD I GO ABOUT IT? OPEN 4 IDEAS, BUT WOULD LIKE TO STAY ORIGIONAL. THANKS............... KURT :'( :'(
I don't see it in the service manual, but generally in that era the filter was standard on the DeLuxe but did not come on the low end series. Low end being "Standard", "Business" or "RoadKing" depending on year. So there is a good chance that you car never had a filter.
If you install a filter, I'd just follow the pictures in the manual for the DeLuxe version setup. If you don't add a filter, just change the oil fairly often (every 1000 or so miles).
THANKS TODD, THATS WHAT I WAS THINKING ALSO. I WANT TO STAY ORIGIONAL, AND I GUESS THAT'S ABOUT THE EASIEST THING TO DO CONSIDERING I PAYED $9.89 FOR A GALLON OF VAVOLINE 10-40. IT'S LESS THAN THE COST OF JUST THE FILTER IN A LATE MODEL CAR. I SAW YOUR WEBSITE AND WAS MOST IMPRESSED SINCE I RESTORE OLD HOMES FOR A LIVING FOR THE PAST 30YRS. BACK IN THE DAY WHEN TEARING THEM DOWN WAS CHEEPER! I WISH THAT I HAD BEEN INTO CARS AT THAT TIME I LOVED TO LOOK BUT NEVER HAD THE AMBITION. MY RESTORATION SKILLS ARE COMING INTO PLAY WITH CARS NOW. THANKS AGAIN...........KURT :o
James T Lentzke, in his Standard Catalogue of Chrysler 1914-2000 (Iola, Wisconsin: Krause Publications, c.20000), page 415, says that an oil filter was an option on the 1939 Roadking. So, you could always add the option the original owner didn't order, and still be authentic.