getting ready to change impeller Outdrive on or off the boat??

[gwgautney]

I am getting ready to change the impeller on my MR outdrive. My question Is it easier to change it with the outdrive on the boat or off the boat. I have it off of the boat now waiting on my transom repair kit and gimbal bearing. Just wondering if I should wait until I do that and reinstall the outdrive then do impeller.

Thanks

 

[thumpar]

Re: getting ready to change impeller Outdrive on or off the boat??

I always did it off the boat. Seems like it would be a pain to get the halves together on the boat. You have to worry about the shift shaft, splines and water tube to all fit right.

 

[achris]

Re: getting ready to change impeller Outdrive on or off the boat??

I've done it both ways. Each has advantages and disadvantages... I would suggest for someone who hasn't done it before, on the bench might be easier.... Have a look at one of the videos in the stickies section.... o.... here's a link.... lots of tips on what to look for....

Alpha style water pump service

And a pressure test before you fill with oil would be a good idea..

Chris......

 

[ktbarrentine]

Re: getting ready to change impeller Outdrive on or off the boat??

+1 on doing it on the bench (since you already have it there anyway.... I'm kinda surprised its not apart already!). That way you can get a good birds-eye view of how things are going back together when you join the halves (look in through the exhaust cavity and watch the water tube go in the right place, and watch how the vertical shaft goes into it's seal in the upper half. Take it slow. Strongly recommend the pressure test as explained in the stickies (low pressure...about 7PSIG, and higher pressure, about 10-15 PSIG). Just gives peace pf mind. And follow your instruction book/drive manual for disassemby, reassembly and torquing....
Changing the gimbal bearing? Make sure you have an alignment tool and do the proper alignment checks after. (I always check alignment before the drive goes back on the boat). Best of luck!

 

[Eric 3.7LX Alpha 1]

Re: getting ready to change impeller Outdrive on or off the boat??

Definitely do it now, there's no reason to re-install the entire drive back then take the lower off.

If the seal at the bottom of the drive shaft housing (upper half) is worn.... the one that the lower shaft goes thru.... then you'd have to replace it upside down which might be a challenge.

Did you drain the drive already?

 

[camalot]

Re: getting ready to change impeller Outdrive on or off the boat??

If it's just an impeller change, I find it easier to just to remove the lower and leave the upper attracted to the boat. Last time I didn't drain the gear oil either, just put a vac pump on the upper vent plug and removed the lower.

Once removed I put a small plug into the oil transfer hole just for safe measure. Took 30 mins for the whole job!! and didn't lose any oil)

 

[ktbarrentine]

Re: getting ready to change impeller Outdrive on or off the boat??

My impeller change-out is timed to coincide with my other routine maintenance, such as greasing U-joints, inspecting bellows and gimbal, checking alignment, changing gear oil, doing pressure tests, etc. Would never consider leaving the upper half on unless the impeller job was emergent between normal inspection/maintenance periods.