BF225 lower unit shaft change.

I have a BF 225 30” lower unit that has a bad bearing. I have a spare that has about 100 hours on it. However, the spare had a 25” shaft. I would like to take the 30” shaft out of my “bad” unit and put it in my good unit that currently has a 25” shaft. I have had lower units apart to replace seals so I understand the basics. My question is…. Anything major to changing out the shaft. Is it as simple as taking the output assembly out of the case, terming the nut on the bottom of the shaft, remove the gear, pull the shaft, then put everything back together? Does anything have to be re-shimmed?

Thanks in advance for any info.

Hi,
I see that you haven't gotten any replies yet so I thought I'd bump the post to keep it current.

I don't have any experience with the larger outboards so anything I offer is pure speculation. But, looking at a pdf manual, what you're thinking of doing seems feasible to me. The shims involved are to adjust for the bevel gear contact depth. So, if you all you swapped was the maunshaft, then the gear contact shouldn't change.

Again, just a guess. I don't know about any differences such as mainshaft diameters or shift shaft lengths. If you are working with the shop manual though, the gear case section looks to be in depth and seems to have all the info. That and some decent measuring tools might be all you need.

I think it would be well worth the $140 or so to have it for reference while doing this.

Good luck.

If you swap the driveshaft you have to check shimming of the pinion gear !