165 SternDrive Question

Muqwump

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I have a 1971 165 inline 6 with a 165 SternDrive and I had a problem with the outdrive not wanting to go into neutral. It was either in foward or reverse and it was very hard to get there. The easiest way was to shut it down and then switch it in to neutral. Since then, I have replaced all the cables, control box, lower shift cable, interupt switch and bellhousing. I am able to switch into foward and reverse but there is an intermitten knock comming from the lower gear housing. It sounds like the ramps are not making full contact when in foward or reverse but is engaging. With the engine off, i put it in full foward gear and spun the prop to listen to the contact. I did the same in full reverse. The ramps are hitting harder in foward gear more than reverse but feels like it is barely rolling over the ramps in either direction. I think i need to have the lower gear housing overhauled but it may be cheaper to just replace the lower part of the outdrive. If i need to replace the lower unit, what do i need to look for other than a 165 to 1 gear ratio? Will other lower units fit on this drive?

Thanks
 

Fishermark

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Re: 165 SternDrive Question

I would suggest a unit from Sterndrive Engineering. That's IF your lower is bad. If you decide to go that route, just tell them what you currently have and they can help you get the right unit.
 

Muqwump

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Re: 165 SternDrive Question

Thanks for the info FisherMark..
I contacted them and they wanted for me to take it apart and count the splines on the shaft. If it has 13 splines then they can help get a new lower gear case. If not, they can not help. Is there any other options like another type of alpha that would fit that i can get used or reconditioned cheaper rather than buying a new one? I see them on ebay all the time but not sure which one would fit my drive. If there are no other options but to find just a 1 drive to fit it, then i will consider buying a new aftermarket one if availible.
 

Fishermark

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Re: 165 SternDrive Question

Is there any other options like another type of alpha that would fit that i can get used or reconditioned cheaper rather than buying a new one?

Are there other options?

Sure!

But buying a used unit is a gamble at best - regardless of what a seller will tell you. :rolleyes:

And I don't believe there is any way you could buy a reconditioned unit (truly reconditioned / rebuilt) for less than you can buy a new aftermarket one.
 

Muqwump

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Re: 165 SternDrive Question

Good point... it is a gamble at best. I was thinking i could find some parts off another project boat that the investments have already been made but willing to part. I just need to have some type of direction on what can fit up to what i have already.
 

Fishermark

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Re: 165 SternDrive Question

To the best of my knowledge, an Alpha lower will fit a pre-alpha upper like yours. Your lower unit will have a pre-load pin on top of the drive shaft, while the alpha will not. But that's no biggie.

Having said that, I don't know about the "13 splines" issue. Maybe the real old ones have a different number.... Being a 71 I would GUESS you would be okay, but the only way is to pull off the lower and look.

Just so you know - the aftermarket unit is the same as an Alpha. (Not to be confused with a gen 2 which will not work for you).
 

Muqwump

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Re: 165 SternDrive Question

To the best of my knowledge, an Alpha lower will fit a pre-alpha upper like yours. Your lower unit will have a pre-load pin on top of the drive shaft, while the alpha will not. But that's no biggie.
You are right on the money.. mine does have that pre-load pin on top of the shaft as you described. Im not sure what that is for but i have seen some photos off others for sale that did not have it, so i have over looked those. When you say an Alpha lower will fit, what type are you refering to? I have been told many different things like any of them that are from 140-260 would work or even the Gen 1. Some of them have a vent hole where the split line is from the upper and lower and i believe it has something to do with the water pump but not for certain.
 

Muqwump

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Re: 165 SternDrive Question

.... Mine does not have that vent hole that goes toward the water pump.
 

Fishermark

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Re: 165 SternDrive Question

You are right on the money.. mine does have that pre-load pin on top of the shaft as you described. Im not sure what that is for but i have seen some photos off others for sale that did not have it, so i have over looked those.

As I understand it the pre-load pin was there to put a load on the gears to ensure the proper gear mesh... or something like that. Mercruiser redesigned the gear set so it no longer needed the pre load to get the right mesh. That may be a little over simplified... but that is basically the deal. Bottom line - you can use either one.

When you say an Alpha lower will fit, what type are you referring to?
Well... an Alpha is an Alpha. ;)

After the Alpha came out, they came out with a newer model called a Gen 2. Also known as an Alpha 1 Gen 2. (There is no "Gen 1" - you either have an Alpha 1 or an Alpha 1, Gen 2).

You cannot use the gen 2.

Here is a site that may help answer some questions:
http://www.mercstuff.com/drive_idalpha.htm
 

Muqwump

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Re: 165 SternDrive Question

Thanks for that link! That may also help others down the road as well as these drives fade out and have the same questions. My boat has been to three different service centers and my outdrive has been refered to as three different things so i get really confused. It has been refered to as a Early Model 1 drive, a 1 drive and a Pre-Alpha. Is there a difference between them? I have no idea what a Gen 1 was either that is why i am here. I believe Mercury or SternDrive Eng. refered to it as that. So just for clarification.... the only drive that wont fit is the GEN 2? And i will be looking for either a Pre-Alpha 165 or an Alpha 1. Correct??? Does the year model matter?
 

Fishermark

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Re: 165 SternDrive Question

The problem with the names is that many people use them interchangeably... and not always correctly. I just went through this with my dad's boat. Here's a link showing some history:
http://forums.iboats.com/showthread.php?t=230711&highlight=progress

There is a model 1... there is a type R... there is a pre alpha... etc. Most of the stuff before the alpha came out is referred to by most people - again, correctly or incorrectly - as "pre-alpha." I know from experience that some parts are interchangeable and some are not.

I also know from experience that most marine techs are not experienced with the differences. That's why you are probably better off replacing the lower unit (at the very least) with a newer model alpha or aftermarket Sterndrive Engineering unit.
 
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