23 Reo 230 #1 Posted June 22 I am having trouble finding a black Onan 122-0800 oil filter for my 520H. I bought a Fleetguard LF3339 and it is too long. The black Onan filter is 4" long but the Fleetguard is longer. Is there a trick to installing the Fleetguard? Is there a substitute filter that is the same size as the black Onan 122-0800? Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,585 #2 Posted June 22 See if this link works and check filter number 51762 https://www.wixfilters.com/en-us/filter-finder.html Works for me 1 Share this post Link to post Share on other sites
lynnmor 7,936 #3 Posted June 22 Many green Onan 122-0800 boxes contain a white Fleetguard LF3339 since both companies are owned by Cummins. I have been using the Fleetguard on 1991, 1996 and 1997 520H's for years, you just need to find the angle and they go right in. You might want to check if your engine moved from loose mounting bolts. 1 Share this post Link to post Share on other sites
Lee1977 7,295 #4 Posted June 23 (edited) ''''''''' I have been using NAPA Gold 1348 on both my Onan and Vanguards. They are around 3 1/4" tall. Edited June 23 by Lee1977 1 Share this post Link to post Share on other sites
lynnmor 7,936 #5 Posted June 23 (edited) 7 hours ago, Lee1977 said: ''''''''' I have been using NAPA Gold 1348 on both my Onan and Vanguards. They are around 3 1/4" tall. I wonder how the gasket fits around the flutes on that short filter. Do they fit the same now that they are made in China? Edited June 23 by lynnmor 1 Share this post Link to post Share on other sites
Lee1977 7,295 #6 Posted June 23 2 hours ago, lynnmor said: I wonder how the gasket fits around the flutes on that short filter. Do they fit the same now that they are made in China? I found out that NAPA Gold filters are no longer made by Wix . I buy from Fleet Filter and mine are 3 or 4 years old as I bought a box of 12. Don't know who is making NAPA filters now. Fleet Filter went to Wix 51348. I had the cover off my Onan last fall to clean the fends and blew the gasket off twice after that, Had to clamp it between front and side cover to keep it on. It wasn't blowing off before I cleaned it. 1 Share this post Link to post Share on other sites
kpinnc 14,899 #7 Posted June 26 On 6/23/2025 at 1:16 AM, Lee1977 said: ''''''''' I have been using NAPA Gold 1348 on both my Onan and Vanguards. I was gonna ask you about using them on Vanguards. Thank you! Share this post Link to post Share on other sites