2006 Mercury 9.9 Lower Rebuild

I drained the lower unit oil the other day because I heard a weird noise, and out came enough metal to fill a mouth full of cavities... :x

I can't seem to find a rebuilt, or used lower for this, so I figured I'd take the LU apart and see what was wrong. At this point, what could it hurt?

I removed the propeller shaft, and its associated assembly. So far it looks like I need a new reverse gear and pinion gear. The pinion is badly chewed up, and the reverse gear has one tooth pretty badly chipped. The forward gear looks good so far, but I can't fully inspect it.

I assume all the bearings will need replaced?

I removed the water pump housing, but I haven't figured out how to remove the pinion gear, thus freeing the drive shaft. The pinion looks like its pressed onto the driveshaft splines. I have a feeling I am going to need some sort of puller?

I've got the service manual on the way from eBay. Hopefully that sheds some light on my situation.

I wouldn't be entertaining this if the price of 15+ year old 9.9/15's weren't so stupidly expensive. My year and older 9.9's are going for $1000 - $1250 online!!! A local shop has the same 2006 9.9 "with only five hours" going for $2000?!?! In the event I can get this back together, I'll use it for a few months and pick up a 15 hp at a show.

Here are some pictures of the internals. Any pointers would be appreciated.

https://drive.google.com/folderview?id=15QWQ7ehVMsmw7yyTbbV8ilaxKYR-YIG8

2006 Mercury 9.9
Short Shaft, Non-Bigfoot
Model#1F10201FK
SN 0R068951

On the older Mercs, once you removed the prop shaft carrier then you had to loosen the nut on the bottom of the driveshaft. That would release the pinion gear and allow you to remove the drive shaft. Other than that, I'm not much help. The service manual should tell you what you need to know.

MrGiggles said:

On the older Mercs, once you removed the prop shaft carrier then you had to loosen the nut on the bottom of the driveshaft.

Click to expand...

I was looking for a nut, but I don't see one.

Chimpo said:

MrGiggles said:

On the older Mercs, once you removed the prop shaft carrier then you had to loosen the nut on the bottom of the driveshaft.

Click to expand...

Click to expand...

I was looking for a nut, but I don't see one. Check the link below for the view of the pinion nut.


https://drive.google.com/file/d/1ZLP8X_tSM6xjiVPiOc_IUm_n7EZNcHOf/view

So, I got a little rough with a drive shaft and the pinion gear fell right off. I'm guessing this it's not what a healthy pinion gear should look like? The reverse gear has a chipped spline as well.

Next task is to remove the prop shaft from the assembly so that I can pull the reverse gear. It's stuck on pretty good. I whacked it around with a hammer two days ago without much luck. I've got it soaking in PB blaster as we speak. I believe it's the thrust washer that's corroded on to the shaft giving me a hard time.

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I would suggest an OEM service manual and it appears everything you have removed so far is toast. If you bide your time eBay usually is a pretty good source for OEM manuals.

I realized I was in it deep so I did just that. I picked up a used service manual for about $26 on eBay.

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You should be good to go, just take your time and go by the steps outlined.