SternDrive Gear ratios
 

I have a 1991 Mecury Alpha one Gen I sterndrive with a 1.98-1 gear ratio. It
is mounted to a 3L 4 cyc engine but the sterndrive ceased this summer and I
have found another one but it has a 1.47 ratio. Can this sterndrive be
mounted onto the same engine. What about a later year model like a 1995
alpha one gen one would that fit? Lastly what does the upper unit gear ratio
relate to? Torque...engine speed?

Lots of questions

SternDrive Gear ratios
 

You could use it, as in it will fit, but your present prop would be WAY
wrong and you would have some problems propping it.
The ratio in the outdrive affects the prop rpm.
All the Gen 1's will fit, but save yourself some problems and buy the
correct ratio. And no, it's not worth it (unless drive was free along with
the parts) to change ratios. BTW, you need quite a few special Merc tools to
do it, so get the do it yourself idea out of your mind.


wrote in message
t...
I have a 1991 Mecury Alpha one Gen I sterndrive with a 1.98-1 gear ratio.
It
is mounted to a 3L 4 cyc engine but the sterndrive ceased this summer and
I
have found another one but it has a 1.47 ratio. Can this sterndrive be
mounted onto the same engine. What about a later year model like a 1995
alpha one gen one would that fit? Lastly what does the upper unit gear
ratio
relate to? Torque...engine speed?

Lots of questions

SternDrive Gear ratios
 

That 1.47:1 is a V-8 drive ratio. You will lug your 3.0 without a
ridiculously low pitched prop, which if you used it, would not be as
economical or effective at the hull speeds you want to operate your boat at.
Get the right ratio. Check with Doug Russel's www.dougrussell.com for
competitive pricing. Also check with your local ships store to look at the
Sierra replacement drives.

Rob
*
*
*

wrote in message
t...
I have a 1991 Mecury Alpha one Gen I sterndrive with a 1.98-1 gear ratio.
It
is mounted to a 3L 4 cyc engine but the sterndrive ceased this summer and
I
have found another one but it has a 1.47 ratio. Can this sterndrive be
mounted onto the same engine. What about a later year model like a 1995
alpha one gen one would that fit? Lastly what does the upper unit gear
ratio
relate to? Torque...engine speed?

Lots of questions

SternDrive Gear ratios
 

Why did it quit? Sometimes there are cheap reasons for that, like stripped
out coupler.

wrote in message
t...
I have a 1991 Mecury Alpha one Gen I sterndrive with a 1.98-1 gear ratio.
It
is mounted to a 3L 4 cyc engine but the sterndrive ceased this summer and
I
have found another one but it has a 1.47 ratio. Can this sterndrive be
mounted onto the same engine. What about a later year model like a 1995
alpha one gen one would that fit? Lastly what does the upper unit gear
ratio
relate to? Torque...engine speed?

Lots of questions

SternDrive Gear ratios
 

The upper gear set ceased in the housing due to lack of oil. I have removed
it and am looking into the possibility of replacing the gears set but others
that have posted here say its a bad idea. It look rather straight foward to
me. The gear set run about 600


"Lawrence James" wrote in message
link.net...
Why did it quit? Sometimes there are cheap reasons for that, like
stripped
out coupler.

wrote in message
t...
I have a 1991 Mecury Alpha one Gen I sterndrive with a 1.98-1 gear
ratio.
It
is mounted to a 3L 4 cyc engine but the sterndrive ceased this summer
and
I
have found another one but it has a 1.47 ratio. Can this sterndrive be
mounted onto the same engine. What about a later year model like a 1995
alpha one gen one would that fit? Lastly what does the upper unit gear
ratio
relate to? Torque...engine speed?

Lots of questions

SternDrive Gear ratios
 

You need to replace all the bearings and seals in the gear housing. You most
likely will need a new yoke. You need to find out where the gear oil leaked
out. You need to reseal the gear housing. You need to take apart the
propshaft housing and clean and inspect everything. You might as well reseal
it as well. You need to carefully set backlashes and preloads while
reassembling. You need to borrow or rent special tools. You need a genuine
Mercruiser service manual. The good news is if you follow the directions in
the manual you will have done a fine job. Anyone with a fair mechanical
aptitude can do this job with the right tools.
wrote in message
t...
The upper gear set ceased in the housing due to lack of oil. I have
removed
it and am looking into the possibility of replacing the gears set but
others
that have posted here say its a bad idea. It look rather straight foward
to
me. The gear set run about 600


"Lawrence James" wrote in message
link.net...
Why did it quit? Sometimes there are cheap reasons for that, like
stripped
out coupler.

wrote in message
t...
I have a 1991 Mecury Alpha one Gen I sterndrive with a 1.98-1 gear
ratio.
It
is mounted to a 3L 4 cyc engine but the sterndrive ceased this summer
and
I
have found another one but it has a 1.47 ratio. Can this sterndrive be
mounted onto the same engine. What about a later year model like a
1995
alpha one gen one would that fit? Lastly what does the upper unit gear
ratio
relate to? Torque...engine speed?

Lots of questions