Driveshaft beating/seal assembly on Merc 50

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PSG-1

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I have a 2007 2 stroke Merc 50 on my 16 foot Triton.

Since I use the boat a lot in mud and sand, I change my water pump at least once a year, whether it needs it or not.

When I had the lower unit off the motor today, I noted that the bearing/seal cone where the driveshaft goes into the gearcase, had some corrosion. I can look at it and tell that it is going to have to be replaced at some point.

I had the same problem on a 2005 25HP merc, but I got rid of the engine before I had to replace this part. So, I've never replaced one of these pieces before. Looking at a parts diagram, it looks like it's a simple press fit. Is there a way to remove it without having to take the driveshaft out or disassemble the gearcase? Or is it more involved?
 
Does it look like parts 69 and 70 in the link?

https://www.boats.net/parts/search/Merc2/Mercury/50%20%284%20CYL.%29/5531630%20%26%20Up/GEAR%20HOUSING%20%28PROPELLER%20SHAFT%29/parts.html

If it's like my old Johnson (get out of the gutter), the seals are in a bearing housing carrier and pressed in fairly tight. The carrier just slid out if I remember correctly and I used a pilot bearing remover tool attached to a sliding hammer which you can rent at an auto parts store to removal the seals in the carrier. After replacing my first one, I just decided to buy the tool from the store for the deposit price as it made the next seal removal a lot easier. I also used it on the seal for the drive shaft on the lower unit. One word of caution, WATCH YOUR FINGERS!!!!!!!!!!!!!!!!

Oops, I see you mentioned drive shaft, not prop shaft.
 
I had the year model wrong. It's a 2005 engine, the boat is a 2007.



Anyhow, it looks like parts #22 and part #23 in this diagram:

https://www.boats.net/parts/search/Merc/Mercury/2005/1050412DN/GEAR%20HOUSING%28DRIVESHAFT%29%281.83%3A1%20GEAR%20RATIO%29/parts.html

Part #23 is the critical component, as it is a seal. However, it is held in place by part #22, which appears to be a machined aluminum cone with a countersunk surface to hold the seal in place.

The bearing, or part #27, is not compromised at this point, and does not need to be replaced, as long as I replace the seal and the cone that holds it in place before they finally go bad. I'm sure to replace the bearing, disassembly of the housing would be necessary.

But it looks like part #22 can be pulled by using a set of vise grips and doing a little twisting and pulling, as it is only press fitted into place. Or it may be threaded, it's hard to tell by the diagram. But in either case, I would think it could be removed while leaving the driveshaft in place.
 
How odd, looks like there are back to back seals (#23 and #24) that have different part numbers and prices?

Be careful of the housing the seals sit in as the metal might be soft.
 

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