Water Pump Service - Alignment Pins?

[akincer]

I'm getting ready to do change the water pump impeller on my Alpha 1 Gen2 drive. I've found a lot of good info on this board and have reviewed some videos on the procedure. It looks straight forward enough. Parts are on order. The one thing that is not clear is how important the alignment pins are. I see a number of references that show using the alignment pins. I also see articles and videos that don't use the pins. How many people have done impeller replacements without the pins and did you have bad results from that?

 

[akincer]

So, is everybody using the alignment pins when they impeller service?

 

[Bondo]

So, is everybody using the alignment pins when they impeller service?

Ayuh,.... On the Alpha, Gen.IIs,... Yes,...

 

[akincer]

Looks like I will be ordering the pins!

 

[achris]

I have heard quite a few people say they don't use the pins and don't have any problems. My only comment is that they haven't a clue what they are doing, and shouldn't be allowed within 50' of a marine engine! Apart from RTFM, just have a good look at the housing and you'll see why using the pins is NOT debatable. If you don't use them, that housing will NOT be in the right place. It will pump less water and run the very real risk of the drive shaft rubbing on the centre hole. That leads to a damaged housing, which lets air into the system and, more importantly, a drive-shaft with a groove in it, which will be the exact place it will shear off if the prop impacts!

 

[akincer]

achris,

I saw your youtube video on this topic. You provided a really good explanation and visual on exactly what can go wrong without the pins. Thanks that was very helpful! For anyone not using pins, it's worth your time to check out the video.

 

[MarkSee]

Alignment pins + newer style 1 piece faceplate/gasket = guaranteed success.....especially some of us non-mechanics who only need to do this once every couple of seasons and need all the assistance they can get.......:faint2:

I admit, I never had to mess with the 3 separate gaskets in the time I serviced my a1g2 and maybe with the pins it's cake, but should I ever work on one again, I will only be using the 1-piece.....regardless of the few extra dollars it costs.....

Mark

 

[sgtnoah]

I am a large equipment mechanic and am probably not qualified to give advice on marine matters... For what it's worth, I cut the heads off of two bolts and used them as alignment pins. Seemed to work well in a pinch.

-- Pete

 

[achris]

I am a large equipment mechanic and am probably not qualified to give advice on marine matters... For what it's worth, I cut the heads off of two bolts and used them as alignment pins. Seemed to work well in a pinch.

-- Pete

Doesn't work. The alignment pins are stepped. The thread is M6x1.0 but the main shaft of the pin is 7mm diameter.

 

[alldodge]

The thread is M6x1.0 but the main shaft of the pin is 7mm diameter.

Looks like here is the info for someone to make there own if they wish.

6mmx1 die 5.00 http://www.amazon.com/Metric-Right-Thread-1-0mm-Pitch/dp/B00841JDV4
7mm steel rod 26 inch long 5.70 http://www.globalindustrial.com/p/m...FW5E7rbMoBWrhDnP1FmR0aAqot8P8HAQ&gclsrc=aw.ds

Sierra alignment pins 31.99 http://www.iboats.com/Pump-Alignment-Tools-Sierra/dm/view_id.203948
Merc 33.56

Make one for your self, or several and sell