2003 MerCruiser 4.3MPI Alpha I Gen II with an awful noise, need help identifying.

Scott06

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Is the shifter and drive in forward ? There is also a push to disconnect for the speedo tube under there below bellows

when you broke the seal the drive oil resivoir from engine compartment will start leaking unless you pull it back enough to get the popper valve in the lube hose to close

i think some guys where the gimbalbearing is rusted to the drive shaft have use trim cylinder and a block of wood between the transom and top of drive to push the drive off... but make sure it is full in fwd otherwise you’ll break the shift mechanism
 

120mmAPFSDS

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Got the drive off. We had to use the trim hydraulics to pop it off and it went so much smoother than any other method we tried. After getting it off, it was very clear that the drive has not been serviced in a while and there is evidence of marring on the exterior of the ujoints. We cranked the engine without the drive and it sounded perfectly fine so our problem must be in the drive, no? My next question is what are the next steps? Any pointers in what to do with the drive or how to service it are appreciated. You guys have been correct thus far, so much appreciated. Requests for additional information or pictures/video will be answered.
 

Bondo

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and there is evidence of marring on the exterior of the ujoints.

Ayuh,....... That's 1/2 of the noise,..... the other 1/2 is whatever they were hittin',.....
 

120mmAPFSDS

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I've been watching videos on the various nuances of working on this stuff, and it seems important to note that the gimbal bearing came out with the drive, and did not stay within when the drive was removed. It's stuck on the shaft, but rotates and has a little play in it. Could have been the cause of the difficulty removing the drive. There's also metal shavings present in the area around the u-joints. The bellows and bell housing seem alright. I think the noise may have been coming from the gimbal bearing and not the u-joints, as the u-joints don't really have too much scuffing on them.
 
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Bondo

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and it seems important to note that the gimbal bearing came out with the drive,

Ayuh,..... That's a serious problem, the bearin' needs changin',.....

It's usually caused by water, where it shouldn't be,.....

I haven't seen that particular t-stat housin,.....

I'm guessin' the forward right-hand hose in yer picture comes from the transom, under the motor, through the p/s cooler, behind that alternator, up to the t-stat housin',......
If so,..... That's where ya plumb in in-comin' water from yer garden hose,.....
 

120mmAPFSDS

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Got the hose in just past the water distributor housing, and it seems to work. Engine sounds just fine. Funnily enough, the alternator decided it was prime time to roast itself so now we've got that to replace before anything else. Hand-spinning the outdrive results in a noise that probably shouldn't be happening so I guess we know where the issue is. We're not sure whether or not it's worth trying to fix the darn thing...
 

alldodge

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We're not sure whether or not it's worth trying to fix the darn thing...

That is a rough one to try and help from a distance. Drain the gear lube and see what you find

Your cooling system is called a single point drain. Connecting the hose at the distribution housing is good.
 

Bt Doctur

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get a hose from a washing machine, cit it in half, stick the end into the water inlet hole on the transom "B"
gimbal-housing.jpg
 

120mmAPFSDS

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Bought a new outdrive, new bellows kit, and new alternator. We're gonna get this sucker running. You guys know good resources and tips on doing such a thing? We'll need all the help and knowledge we can get.
 

120mmAPFSDS

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We've run the engine on a hose and it sounded fine. Now we're looking to get the bell housing off to replace the bellows and most things within the bell housing. Are there any tricks to doing that?
 

Bt Doctur

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being a gen ii type remove the trim senders, use the tool to remove the hinge pins. pull the ring from inside the bell, carefully raise the housing and cut the oil hose about in the middle, remove the water hose clamp and hose, slip bellow out of its groove and slide back the housing. If your replacing the shift cable at this time get a control cable solid core . Remove your shift cable core, insert the control core from inside the boat to use as a guide until it comes out the back of the shift boot. remove old cable core leaving the solid core in its place
 

120mmAPFSDS

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Cutting the oil hose sounds like a bad idea. The bellows kit doesn't include a replacement. What's the deal with that?
 

Bt Doctur

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99% of the time you break the plastic oil fitting requiring the removal of the steering cylinder to remove the E clip to remove the old broken fitting
a brass nipple to rejoin it
 

kulle

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did you guys ever figure out what the burst of smoke was? funny I was winterizing my '93 4.3L and spraying fogging oil in carb when i recalled a little pop/smoke smoke before the engine starved out( as it was supposed to according to manual). havent fired it back up since, but when i removed my bell housing I found a water shutter valve lodged in the exhaust bellows. Any chance that could have been what you experienced, a shutter breaking or was lodged or blocking exhaust , they are rubber and would smell and smoke? just a thought from a rookie
 

120mmAPFSDS

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did you guys ever figure out what the burst of smoke was?

I think we just went with the narrative that the gimbal bearing getting lodged on the shaft it sits around is what caused ours. Other than that we're still clueless
 
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