.... The lower shift cable is a wear item that gets replaced regularly, somewhere around 5 year. ....
I'm sorry, but I am going to have to dispute this comment.
If nothing has failed that will cause a lower shift cable to have excess load on it or for it to have ingested water, (or it's been burnt by the exhaust due to a 'lack of water' overheat) there is no reason they wouldn't last 20 (or more) years. Mine is 11 years old, my friend's, whom I have maintained since I installed it in 1995, is still original. My previous V6, when the guy I sold it to, sold his boat was also still original and it was 21 years old at that time. I have another friend who has just bought a boat with a 2006 V6 and it also is still on the original cable.
There seems to be a plethora of mis-information regarding replacement times on a lot of Mercruiser items. I have in the past, noted the following...
Bellows. See far too many people saying this is an annual (or bi-annual) replacement item. On a VOLVOs yes, but on a Mercruiser NO. Bellows should easily last 10 years.
Gimbal bearing. Another one that too many people are pulling out a long way before they are due. The old, greaseable types, if greased at service time and the engine kept in alignment, would last many many years. 10 years minimum, 20 years not uncommon. That friend who's engine I installed in '95, still original. Same with my previous V6, and my current 11 year old V6 also, still original. The sealed, non-greaseable, I haven't replaced one yet. The only reason a gimbal bearing would fail is if the bellows leaked and the bearing was flooded, and at that point, I would be replacing the bearing, the unis and the bellows anyway..
Impellers. Here's where is does get tricky. The older MC-1 to Alpha impellers do need to be changed at least on a bi-annual (2 year) basis. If the boat is used less frequently (less than 50 hours a year), the impeller should be changed annually. However, the newer style, Alpha Gen II, are good for a minimum of 3 years/300 hours, as is the Merc High Performance gear oil. I'm not advocating this, but I have seen Gen II impellers that were 7 years old, come out still looking new. And this BS about 'blade set' is just that, BS. The impeller blades will get a 'set' in them about a month after being installed. They all do. And it will stay that way when you pull it out. Blade set is NOT an indicator that the impeller needs to be replaced. If it was, you'd be replacing your impeller every month! Age, burning, blade wear, cracking at the blade root or de-laminating from the hub are the indicators.
I hope this clears up any doubts.
WaterKrafter, Look at my videos for the link to the shift cable adjustment procedure in the 'My Videos' at the bottom of this post's signature..
Chris..........