Remove entire drive to replace impeller? Or just drop lower unit?

[boozer1966]

Replacing impeller on 1984 Alpha One R. Have seen video of it being done by separating lower unit with upper still attached to boat. Have also seen and read it done by dropping entire drive first. Recent bellows/gimbal replacement, so I know what's up there. Any thoughts?

By the way, new boater here. Great site. Excellent source of info. Keep it coming.

 

[Don S]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

Since this is your first time, remove the drive. It will make the job easier, plus it will allow you to inspect the bellows, ujoints, gimbal bearing, check alignment, and GREASE the COUPLER SPLINES, which needs to be done yearly.

 

[Oshkosh1]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

Since this is your first time, remove the drive. It will make the job easier, plus it will allow you to inspect the bellows, ujoints, gimbal bearing, check alignment, and GREASE the COUPLER SPLINES, which needs to be done yearly.

Absolutely...

It's not the removal which you will find is much easier...but the reinstallation.

Make a roller drive stand...plenty of designs, or as I do...use a couple of "Workmate" benches. One to hold the entire drive upon removal then the other to hold the upper after you split it. After you've maintained/replaced/greased everything...re-attach the upper back onto the lower, lift the whole thing out and put it back on.

Just make sure you glue the ring gasket into the bellhousing, keep the shifter/shift shaft full "forward" and the prop shaft "locked" so it doesn't turn CCW while installing and torque everything evenly to spec (48lbs if I remember correctly).

Good luck!

 

[cr2k]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

You call really. I do it just the lower but I have been doing it for 18 years. Just watch the water tube do it in forward gear so you can turn the prop shaft a little (CCW) to line up the properly greased vertical drive splines. Watch the shift shaft too.

 

[boozer1966]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

Thanks Don. I just did a bellows/gimbal bearing job. So I have a pretty good idea of what's up there. If that's not an issue, still remove the whole drive?

 

[Don S]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

Thanks Don. I just did a bellows/gimbal bearing job. So I have a pretty good idea of what's up there. If that's not an issue, still remove the whole drive?

Until you are sure how everything goes together correctly at the same time, yes. Pull the drive.

 

[boozer1966]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

Many thanks! I'll let you know how it goes.

 

[ktbarrentine]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

JM2C.... I agree with pulling the drive. Much easier to join the halves on the bench (can see inside the front part of the drive while you do it. And then when you do your pressure test (you do that, don't you?), it is much easier to soap test and find any errant leaks, if necessary. +1 on all the standard lube and general inspection PMs, too. Like I said, though...JM2C. KTB

 

[Speed1v8]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

Just pull lower out its simple why drop whole thing make guy work more remove 6 bolts on lower unit pull down couple times bam it's off. Set it aside work on it simple. don't forget drain the oil first.

 

[Oshkosh1]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

why drop whole thing make guy work more

Removing the lower is NOT the issue(although I can remove the upper quicker)...re-installing it is.

I can use my cordless impact...zip off the 6 bell housing nuts, three trim ram nuts, give it a couple of pulls(I remove one of the forward and pull the stbd ram off), and have the entire unit off in 3 minutes.
THEN
I can remove the upper, work on the lower, grease the splines/u-joints, and set the upper back onto the lower with ease at waist level and at my bench...not kneeling on the floor, lining everything up by feel, all the while fighting gravity.

Hey...I've done it both ways, and find removing/installing the unit as a whole is much less of a task.

Different strokes...

 

[Grub54891]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

Ok Oshkosh, I hope you are not using that impact to re-install the drive! We had a tech doing that and we had to replace the gasket's on 6 different drive's, including the nut's. The gasket's were smashed right out causing leak's into the bellow's. This was after we told him not to do that! He is no longer with us........ There is a torque spec for that,our manual's say 50 ft lbs. even at that the nut's should be replaced as they do wear out so they will over torque and cause the same issue.
My 2 cent's.... Grub

 

[Oshkosh1]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

Ok Oshkosh, I hope you are not using that impact to re-install the drive!

Nope...1/2" dial torque wrench to 48lbs and new nuts last month.

 

[boozer1966]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

For what it's worth, I just dropped the lower half. Came off and went on without a problem.

Again, many thanks for all the input.

 

[ziggy]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

Any thoughts?

ya missed the pm.
alignment check, gimble brg. check, no u joint lub + no inspection for water in the bellows. no bellows inspection, no coupler lub. on and on. ya need to pull the drive. the pm is important on an i/o imho

 

[Speed1v8]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

He just wants to know about dropping the drive. next one could be about that lil tune up. Good job see not so hard

 

[ktbarrentine]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

Next one may be too late... but good job, and good luck anyway!

 

[boozer1966]

Re: Remove entire drive to replace impeller? Or just drop lower unit?

Like my first post said, I just did a bellows job with gimbal bearing replacement with ujoint inspection, greasing, etc. Just was curious about dropping the lower half for impeller replacement. Thanks for all the input.