Yamaha Lower Unit Bearing Housing

[Kbrink1980]

I am looking to change the two oil seals in the lower unit bearing housing on a 2002 LF225TXRA. Can I change the seals without removing the bearing housing? If I remove the bearing housing, will the bearing stay in the housing? If so, will the needles fall out, or are the needles caged? Thanks for all help.

[rodbolt17]

bearing housing has to be removed.
you will need both seals and the oring.
easy job.
needles are caged and will stay in place.

[Kbrink1980]

leak moved

Replaced the driveshaft seals today. Removed bearing housing. Cleaned surfaces. Replaced o ring and seals. Back together in an hour. Put 11 psi on the unit. All looking good, until about a minute into the drop test. Started losing pressure at the prop shaft seal. Are those two seals removable without removing the prop shaft bearing housing? Id really like to not have to remove that housing. Any insight would be greatly appreciated.

Thanks Rodbolt for the previous info.

[boats.net]

Prop shaft bearing housing needs to be removed to replace prop shaft seals, need to use vacumn tester to test gearcase seals.

[Kbrink1980]

Thank you boats.net moderator. I have also inquired locally with the same answer being given. Tonight the disassembly begins. Was hoping to not have to remove housing and press gear off and shaft out. But, on a positive (hopefully) note, i suppose i'll be able to see the condition of the gears and other components. The joys of buying used.

I'll update when finished and have performed the pressure and vacuum leakdown tests. I prefer to do both tests to ensure a reliable lower.

[rodbolt17]

no need to press any bearings.
however it does require some special tooling.

[Kbrink1980]

Almost together

To follow up, the lower is a counter rotator. Removed prop shaft bearing housing. Took a lot of slide hammer hitting. All looked good. Pressed forward gear off. Checked distance from tapered roller bearing to outside of housing. Checked prop shaft free play. .010". Pressed shaft and bearing out. Replaced seals. Reassembled shaft with original shims and thrust bearing/washer. Pressed on new tapered roller bearing. Tightened lock nut accordingly. Checked distance from tapered roller bearing to outside of carrier housing. Only .002" difference from original bearing. Pressed on forward gear with original shims. Now the question arises. When carrier housing was removed, forward gear felt tight with little side to side movement. Now, forward gear feels tight, with bearing sitting firmly in the race when the shaft is pushed in the forward direction. When the shaft is pulled outward, against the thrust bearing, the tapered roller bearing is not sitting firmly in the race, the forward gear can wabble a bit from side to side. I believe there is some wabble inherent to the design, but how much is allowable? Do i need to remove forward gear and remove .002" of shim? The forward gear does not contact the prop shaft when spun with this wabble. any help would be much appreciated.

[rodbolt17]

what service manual are you using?

[Kbrink1980]

Rodbolt, I'm using the Yamaha Service Manual for the LF225A. It has the part number LIT-18616-02-36 in the lower right hand corner.