Volvo 290dp 2.30 lower on a volvo 280dp 1.95 upper?

[DRCrowe]

I recently picked up a Volvo 290dp 2.30 gear ratio outdrive that has only been used in fresh water and am considering putting the lower unit on my Volvo 280dp 1.95 gear ratio outdrive that has had many years in salt water. My question is, are the lowers the same on both units? is the differences in the gear rations in the upper gear box? I know I will have to re-shim the lower if this is even possible, I'm just not sure if it is?
Thanks! DC

 

[Scott Danforth]

I recently picked up a Volvo 290dp 2.30 gear ratio outdrive that has only been used in fresh water and am considering putting the lower unit on my Volvo 280dp 1.95 gear ratio outdrive that has had many years in salt water. My question is, are the lowers the same on both units? is the differences in the gear rations in the upper gear box? I know I will have to re-shim the lower if this is even possible, I'm just not sure if it is?
Thanks! DC

the gear ratio is determined by the gears in the bottom. same gear box used in the upper on the 270/280/290 regardless of 4 banger, V6, V8, DIESEL or big block

you may want to verify the 2.3:1 ratio. the available ratios were 1.78:1 (big block 740A and B) the 1.95:1 on the small blocks and the 2.30:1 on the V6's (very few existed)

 

[DRCrowe]

Thanks Scott! Yes, it is a 2.30:1. I bought a parts boats for that came with a V6 and that out drive. I really appreciate the education!
The boat I was hoping to put it on is a 28 Bayliner with a 1.95:1 and 350 V8.
Fortunately mine is still working fine.

 

[Scott Danforth]

pull yours apart and look at the gears. may not need anything except a re-seal and paint.

 

[DRCrowe]

That is what I was thinking too! I made the mistake of installing some off brand u-joint and exhaust bellows and they look horrible after 1 season so I will be pulling the drive anyway. I also installed crappy exhaust relief boots which have literaly disintegrated after one season. How important are these? I would rather not slide the engine back and pull the Y pipe if I didn't have too. Thanks!

 

[Scott Danforth]

That is what I was thinking too! I made the mistake of installing some off brand u-joint and exhaust bellows and they look horrible after 1 season so I will be pulling the drive anyway. I also installed crappy exhaust relief boots which have literaly disintegrated after one season. How important are these? I would rather not slide the engine back and pull the Y pipe if I didn't have too. Thanks!

wait until you have to pull the motor to address the idle relief flapper

 

[DRCrowe]

Thanks Scott! Sounds like a good plan!