Dear Mike,
I am not as familiar with the Onan powered cars as I would like to be so here goes...
I used my handy dandy WIX Filter manual for this information. You are absolutely correct about series of numbers not matching number to number. You do better finding a catalog such as the one WIX has to locate odd stuff.
The Onan B48G uses Wix oil filter 51374. Two Fram filters are listed in the cross reference for this Wix number. They are PH3816 and PH2951(the 2951 lists the 51374 as an alternate number).
WIX Technical information element dimensions HT. 3.538, OD 3.013, ID 3/4"-16 threads with attached gasket. This filter is a paper lube filter designed for Full flow (no by-pass). The book indicates the bypass valve (if present) should be set 7-9 lb. The filter information indicates it either has or requires an anti-drain back valve. AC Delco crosses as PF-54. Ford crosses as 81SM-6714-A2A. Chrysler crosses as Mopar L-525. NAPA crosses as 1374 and for the most part mirrors WIX part numbers. I would say find one of these filters and see if it fits what you need
M19SOORKB@Prodigy.Net wrote:
> What is the correct Fram oil filter part number to use in the B48G Onan engine? The Fram catalog says the 3600 filter is correct for this engine, but that filter is TOO LONG! I need a shorter Fram filter! Does anyone know what is the CORRECT Fram oil filter part number for this engine? My automotive dept. expert says that one cannot assume (for example) that any other Fram filter in the 3600 series, e.g., 3614 (which is the correct length) is correct for the application, saying the spin-on threads could be different, no bypass valve may be present, etc. Help, please!
>
> Mike Paul
> Oshkosh, WI