Volvo penta drive

"hi guys , i got a question ,

"hi guys , i got a question , ive got a volvo aq 290 drive with a bad lower unit its a 1.61 setup . i have a good a good aq 275 and 280 spare drives from old boat which are both the 1.61 ratio. can i swap either of these lower units on to my 290 drive
thanks"

You should be able to get the

You should be able to get the 280 lower unit on. Just remember You have to re-shim the upper bearing of lower unit.

"Yes, either of those 1.61:1 o

"Yes, either of those 1.61:1 over-all ratio lower units will work. (Verify the ratio)

The shimming is critical, and not all that difficult to do. (it is a NEG preload, not POS)
Make sure that you carry the original race over with the lower unit. Best to not mix used bearing components!

Also, note that these drives pump oil up from the lower unit. Any metallic contamination in the lower will have made it's way to the upper.
Check the oil drain-back screen!
I'd strongly advice pulling the main drive gear and looking at, and/or replacing these two bearings.
Again, this requires a rolling torque pre-load change and re-shimming!

Good luck with it.

."