Grinded Volvo Penta SX Outdrive Gears

[Ryob]

Really hoping someone can assist.

I purchased a 1998 Four Winns RX with a 4.3GL Motor and a Volvo Penta SX-M 1.79 Outdrive.

As i was using it last week , the upper gears grinded (I think water got into the seal).

I am looking everywhere for a reasonably priced Outdrive to no avail.

Do I need to get the EXACT same Outdrive or
is it possible to get a different gear ratio without much of a change to performance?

I want to get back on the lake ASAP at a reasonable price (the boat is only work 6K so I don’t wanna pay 3000 to fix.

Product number of Outdrive: 3868885

Attached is photo of gears behind shift gear box


Any suggestions ?

 

[criscolumbus]

Think of it the same as the rear end of your truck. You change it for a different ratio and it is like shifting gears. You could sorta compensate it with a different pitch prop but not all together the same.

 

[bruceb58]

You need the same ratio.

You likely ran it low on oil. Couldn't have been water since it would have been at the bottom of the drive.

Did you check the gear oil before you used it?

 

[Ryob]

I did not as I was assured everything was changed, learned my lesson the hard way.

I found someone about 65 miles away with the same drive - but a 1.97 ratio. Would this work, and what would my consequences be to go to the 1.97

it was ran with the 3.0 motor - mine is a 4.3. .

See photo attached:

 

[criscolumbus]

I did not as I was assured everything was changed, learned my lesson the hard way.

I found someone about 65 miles away with the same drive - but a 1.97 ratio. Would this work, and what would my consequences be to go to the 1.97

it was ran with the 3.0 motor - mine is a 4.3. .

See photo attached:

Originally your engine turns 1.79 turns for each revolutions of the prop with the suggested drive the engine will turn 1.97 revolutions for each turn of the prop. So, at the same engine RPM you will be going slower provided you use the same prop. Also, you could easily over-rev the engine and cause damage if you don't limit the engine speed manually.

 

[Bondo]

Ayuh,..... Welcome Aboard,...... You'd need a prop pitched in the High 20" range to tame that gear ratio,....
Not very practical, nor efficient,....

The 4.3l like the gear ratio in the 1,80s, 'n can be run in the 1.60s, yet still be in the range of easily available pitched props,.....

 

[Ryob]

I have a buddy that has a 1.60 Penta SX

Would that be better than the 1.97? I’m assuming it would give me some more torque off the line and then slow down at top end a bit.

 

[bruceb58]

Then you would need a super low pitch prop. Get the proper ratio.

 

[Ryob]

I have an SX-M Drive.

Can an someone tell me if an SX-C1 Drive will work

 

[Ryob]

1.66 Ratio

 

[Scott Danforth]

here is a used upper on fleabay for $700 https://www.ebay.com/i/142529126187?chn=ps

here is another (they are useing youtube to advertize) https://www.youtube.com/watch?v=cwZ0_AHUoJo

 

[Ryob]

I am having a 1.66 Gear Ratio outdrive installed tomorrow.

Any my suggestions on what pitch prop I should use?

 

[Bondo]

Ayuh,...... Start with the one that was on the boat to get some numbers, then decide what ya need,.....