Logo
FULL SITE MENU

BF225A4 - Mid-Shaft Bushing Destroyed but No Damage to Mid-section?

W

wildebeest

Contributing Member
So... I replaced the mid-shaft bearings on both of my 2004 BF 225s. On one of the engines, the bearing was completely destroyed--I only found half of the brass portion. See photo below. I just brushed out all the corrosion in the mid-section where it goes so I could fit the new one in, greased it up, and it went it pretty easily--it did take a few taps on a socket to seat it in there. (The other engine seemed fine. The rubber was weird and deformed, but I replaced it anyway. It was a pain to get it in. It took me 30 minutes.)

I've heard that the bearing going bad can damage the mid-section. The mid-section inside looked fine to me when replacing, but what kind of damage should I be looking for to confirm no damage to the mid-section?


mid-shaft.jpg
 
My mid shaft bushing was almost as tore up as yours, I think its the corrosion that forms next to the rubber on the bushing that eats away the aluminum. If the bushing seized to the shaft and stared spinning it could eat away at the aluminum, its a head scratcher why Honda designed it the way they did.
 
Well, as long as it can be replaced, I would suggest to leave it in. It is my understanding that under heavy load, without the bushing in place, that shaft will flex more than is should, eventually putting excess wear on the roller bearings and pinion gear.

That bushing fails because it's not getting sufficient water to lubricate it. I believe that around the middle of 2007 Honda started installing a redesigned midsection to allowed more water to get on to that bushing, solving the problem.

In older 225's, when the bushing failed, the wobbling motion would eat through the forward part of the midsection, leaving a hole that was not easily seen unless the motor was tilted up and inspected. There were a lot of posts on the Internet about that, and folks were raising h*** with Honda about not initially covering it under warranty.
 
Chawk, Thanks. The exterior of the mid-section doesn't show any obvious damage--smooth paint over aluminum with no cracks or damage. I would imagine that if the the slot where the bushing goes on the interior looks fine, I should be okay since that is where the wear would start?
 
Yes, as long as the bushing fits in snuggly, it should be fine. You should check it every time you check/replace your water pump. Here is something I wrote up several years ago...

Very Good video on the procedure: https://www.youtube.com/watch?v=44ZaDzNck1I

Part Numbers
• Bushing = 40210-ZY3-610 – (Vertical shaft bearing)
• C ring = 9052-ZY3-000
• Flat washer = 9053-ZY3-610
• You’ll also need a pair of snap ring pliers.

Removal

Put engine in forward gear.
Remove the lower unit as if you are going to change the impeller on the water pump. Don’t forget the bolt under the trim tab.
Look up inside where you pulled out the drive shaft. There you will see the bushing held in place by a C clip, riding on a metal flat washer. Remove the C clip. Pull out the bushing.

The outside of the bushing is rubber with a metal bushing inside. That metal bushing rides on a raised section of the drive shaft.
To get the bushing out use a pilot bearing puller - Autozone part 27128 loaner tool

Clean out any corrosion and grease the bushing inside and outside liberally with marine grease. A two inch wide wire brush on a drill extension works well.

Installation

The cut-outs in the bushing go up toward the motor.
 
Can be ommited with no ill effects, have seen plenty of older motors without it. It was supposed to prevent shaft flex and possible water ingress as a result .
 
Back
Top