replacing 450 oil pump

Post support questions about your JD350 and newer crawler here
Post Reply
User avatar
thomasgranat
40C crawler
40C crawler
Posts: 13
Joined: Wed Dec 20, 2017 7:25 pm

replacing 450 oil pump

Post by thomasgranat » Thu Sep 27, 2018 8:34 pm

does anybody know of a good source for a engine oil pump for a 450 straight? the pump casting # is t26320 and the engine block # is ar59065. the engine serial # is missing and I believe I have a later style block but the oil pump is the early type pickup according to my jd manual. been having all kinds of repair fun with this machine. the pump is definatly shot , it has teeth worn to a point and a housing clearance of about 1/32 of an inch. The drive gear bushing is also very loose lots of play. the gears also where very worn with galling on them .we tore it down due to very low oil pressure and lots of bearing metal in the filter. the crank and rod bearings show no discoloration from over heating so we are hoping the pump is the problem. the machine sat for 15 years and the previous owner stopped when he found coolant in the oil. I have since fixed this. the weird part is the oil pressure was at 40 lbs cold idle and after 2 hours run time with 10/30 and a oil change to 15/40 delo the pressure went to 25 cold idle any tips would be appreciated here . when we pulled the pan today it was actually pretty clean, some bronze from the rod pins and a few shavings of bearing material and a couple of steel slivers . anybody have thoughts on this?


thanks tom

User avatar
gregjo1948
350 crawler
350 crawler
Posts: 1000
Joined: Mon Aug 30, 2010 5:58 am
Location: Newark Valley,NY,USA

Re: replacing 450 oil pump

Post by gregjo1948 » Fri Sep 28, 2018 3:52 am

If you were getting antifreeze into the oil pan that might explain the colorful oil. I believe oil and antifreeze don't blend and when antifreeze gets between the bearings and crank, it won't be lubricating as it should and shaves the bearing surface. Eventually the bearing gets too loose and spins , binds, then seizes onto the crank. As the bearing gets looser, there's more clearance producing less oil pressure.
JD 350B diesel 6way blade, Case 580B Loader/backhoe, Farmall 504 high crop w/ flail boom mower, International 404 , International 284 diesel w/belly mower, 1972 Ford F600 dump truck, Galion 3-5 roller, Allis Chalmers D17, 1620 Ford

Post Reply

Who is online

Users browsing this forum: No registered users and 61 guests