Rich16 44 #1 Posted February 12, 2022 Help! - I've got a '96 (maybe '97) 520h p220G I'm trying to get up and running for work. The prior owner stripped the oil filter threads and oil was caked everywhere & filter wouldn't seal - only 500 hrs and otherwise runs well. Engine is off and cleaned - don't see any other problems. I have a replacement Oil Filter Bracket I'd gotten off eBay for parts long ago that looks nearly identical but the porting holes are somewhat different - does it matter? The parts piece uses the 45 degree brass angle with a white pressure sensor from an obvious older model engine. The one I'm replacing with screwed up threads (newer model) has larger port holes coming from the filter compartment - it also uses the black pressure sensor without the 45 degree brass angle. I've been looking for this type exact replacement for a year or so now and really want to get this back running - will it hurt the engine using the older style bracket and can I still use the black pressure sensor despite the holes being different? Everything else looks identical - thanks! Share this post Link to post Share on other sites
Rich16 44 #2 Posted February 12, 2022 Here's some pix to show the difference - the bracket will mount fine but there are definite changes to the port design internally. Share this post Link to post Share on other sites
lynnmor 7,813 #3 Posted February 12, 2022 This has come up before, but I don’t know if the old style was used. Onan changed for a reason, I would hold out for the proper part. 2 Share this post Link to post Share on other sites
Rich16 44 #4 Posted February 13, 2022 Many thanks again Lynnmor - any idea where the best place to find one is? I've tried A-Z, Joe's, and nothing on eBay - anyplace I'm not thinking of? Figured this is going to be difficult to find as it seems it was used on maybe only a couple years later engines. Share this post Link to post Share on other sites
lynnmor 7,813 #5 Posted February 13, 2022 Check with http://boomersonanparts.com/ Perhaps you could open the holes, but if memory serves me correctly there are other differences. 1 Share this post Link to post Share on other sites
Handy Don 14,055 #6 Posted February 13, 2022 The more I look at those images, the clearer the difference in the ports becomes. Any chance of resurrecting the damaged threads? 1 Share this post Link to post Share on other sites
Rich16 44 #7 Posted February 13, 2022 (edited) Hi Guys - there's definitely a design difference between the units - the newer cross-theaded one has a larger area in the casting where the (larger) port enters the filter compartment. Doesn't show up in the pix but there's a larger conical 'bulge' where the port is and a much smaller one on the older unit. Sadly the threads are boogered beyond repair with some broken off completely. There really isn't any room to drill larger without serious damage and possible penetration thru the wall. Seems someone decided a higher oil volume was needed though it's really odd - I can't find anything to suggest this change in the official manuals. I've put a want in the classifieds and will check your link Lynnmor - many thanks. Very weird! Edited February 13, 2022 by Rich16 1 Share this post Link to post Share on other sites
Rich16 44 #8 Posted February 17, 2022 Removed the crud from the side of the Oil Filter unit and lo and hehold! A part number stamped on the side (not inside adjacent the filter threads like other units I've seen and on the spare one I have). The number on the side is: 170-4428, Rev B, Onan 2 - make any sense? Share this post Link to post Share on other sites
lynnmor 7,813 #9 Posted February 17, 2022 @onanparts.com says that all are interchangeable. Not sure but I believe that all of my Onans have the part number inside. 1 Share this post Link to post Share on other sites
Rich16 44 #10 Posted February 17, 2022 Thanks for sussing that out for me Lynnmor - all the oil filter adapters for these I've seen have the number inside the filter compartment - this one is outside & I finally figured it out speaking with Boomer. The number was caked in oil but, once removed, was clearly on the outside of the bracket housing. Don't know yet if Boomer has the exact part but I'll probably just use the one I have and move on. Your help is always appreciated. 1 Share this post Link to post Share on other sites
Rich16 44 #11 Posted February 17, 2022 Lynnmor - Boomer has a new one in the box and we had a nice chat - he'll be my go-to guy for parts from now on. Great heads-up and many thanks again. 1 Share this post Link to post Share on other sites
lynnmor 7,813 #12 Posted February 17, 2022 1 hour ago, Rich16 said: Lynnmor - Boomer has a new one in the box and we had a nice chat - he'll be my go-to guy for parts from now on. Great heads-up and many thanks again. Boomer is a good guy, whenever you call him get comfortable in a nice chair, he will provide good information in great detail. 1 Share this post Link to post Share on other sites
