MERC 225 EFI lower unit poblem

[BW23]

I have a 97 Merc 225 EFI XXL with 207 hours. Aprox. 20 hours ago the engine began making a clank,clank,clank sound that I’ve been try to troubleshoot (mechanical or combustion) for quite some time now.<br /><br />Yesterday I finally removed the drain plug in the lower unit and the gear oil had very fine particles of shinny non-metallic metal mixed in with it. The gear oil did not have any water mixed in with it.<br /><br />With out knowing exactly what failed; can this lower unit gear case be re-built? Or should I plan to replace it with a re-manufactured one?<br /><br />Thoughts please.<br /><br />Thanks,<br />Dave

 

[hondon]

Re: MERC 225 EFI lower unit poblem

I"m not there looking at what you are seeing but I have yet to see nonmetalic metal in my career.Anyway, if your gearoil came out grey and full of whatever kind of flack , that gearcase deserves an internal inspection.Pull the propshaft bearing carrier and have a look.

 

[rodbolt]

Re: MERC 225 EFI lower unit poblem

hello<br /> did you check the propeller torque? a lot of the later motors had the Flo-torqe hubs that require maintence. if they get loose or cracked then they clank a bit in gear at idle speed.<br /> good luck and keep us posted

 

[BW23]

Re: MERC 225 EFI lower unit poblem

The gear lube looked like it had glitter in it.<br />The drain plug had the normal amount of filings/residue on the magnet.<br /><br />The gear case engages in fwd and rev. just fine.<br />The clank sound becomes apparent at 2000 RPM and up. <br />I replaced the water pump this past spring.<br />This is a 2 piece 30" shaft. The prop has been removed and re-installed since the sound became apparent.<br />I know there are many possibilities. I just don't know much about the lower gear case.<br />Thanks

 

[rodbolt]

Re: MERC 225 EFI lower unit poblem

hello<br /> wow<br /> at 2000 rpm its way past a loose prop hub or a driveshaft chatter caused by the shaft moving up and down when lighty loaded. sounds like its time for a unit teardown. the lower unit is cheaper to dissasmble then the power head. you may find a chipped gear. time to get out the wrenches or turn up the radio <br /> good luck and keep us posted

 

[BW23]

Re: MERC 225 EFI lower unit poblem

FWIW,<br /><br />At 3500 RPM's the clank is 300-400 times per minute. <br />Thanks,

 

[BW23]

Re: MERC 225 EFI lower unit poblem

^

 

[BW23]

Re: MERC 225 EFI lower unit poblem

I just got a reply back from another site.<br /><br />Seems the Clutch Dog might need adjusted via the shift cable.<br /><br />Anyone had a written procedure for this adjustment??<br /><br />Thanks,<br />Dave

 

[clanton]

Re: MERC 225 EFI lower unit poblem

The clutch dog should not make a clanking noisy in gear only in neutral, unless it is jumping in and out of gear. I would remove the bearing carrier for a look like hondon said. The adjustment was posted about 30 days ago. You center the slack in the shift linkage on the engine and center the slack in the shift cable, reinstall cable, engine and control in neutral

 

[kingsbiship]

Re: MERC 225 EFI lower unit poblem

I had a 1500 Merc That made a noise similar<br />to what your saying and it turned out to be piston slap in the bottom piston. Hope this isn't your prob!

 

[BW23]

Re: MERC 225 EFI lower unit poblem

Here is the latest.<br /><br />Motor ran fine but made a clank,clank sound out of the lower unit.<br /><br />Mechanic said pinion gear nut came off and then things becamed chewed up. His recommendation is a complete OEM MERC unit at 3700.00<br /><br />My question is...would the prop still turn if the nut came off ?? I would think the gear would then fall off.<br /><br />Boat is 3 hours away so I just can't swing by and check it out.<br /><br />Thoughts please,<br /><br />Dave