I have always taken the time to make certain all splines are going the correct way when I replace my impellers which takes a lot of time. Someone told me it doesnt matter and will self adjust once started. Is this correct? It would save a lot of time. Thanks,

I'd be inclined to have them all going in the correct direction... that is how I've replaced them..... you can always just throw them in... start up the engine.. remove the pump and see if they have aligned or torn off....

Doesn't matter. Not a bit.

I do usually smear them with liquid soap to make them go in easier and keep them running free so they don't get hot on that first dry prime.

Shouldn't matter.

I've just always used grease on the shaft and soap on the blades. Some petro-based lubes can affect the properties of the rubber, but whatever you put on it is gone after five minutes of running.

Use KY jelly!

Sure, soap will harden just like it does if you leave a blob on the countertop. Still is a lube, a pretty good one - I use bar soap on zippers all the time.

KY should work fine!

And without knowing for sure about incompatibilities between the rubber impeller and the grease, I'd much rather leave dried soap on them.

But if you don't plan to use it till May, then leave the old ones in till then. No reason to leave a new impeller all bent up in there like that (my Caterpillar manuals recommend REMOVING rubber impellers during extended layup - I don't do it, but can understand the logic there).

I always use a jar of vasoline. Alittle messy but works.
Always replace the plastic housing. I learned the hard way

Vaseline?

Be sure you KNOW what your impeller is made of.

Neoprene rubber has only a "B" rating against petrolatum, while Nitrile rubber has an "A".

It doesn't matter, though, if you plan to use the boat within a couple of days after installing the impeller. Where it matters is if you grease it up and then let it sit for a few months.

I was just kidding about the KY... that stuff dries up... there are rubber lubricants... try some glycol... (antifreeze)... it won't bother the rubber and won't dry up either.

Why not put them in right, I have found it to be easy with some soap and water.
I would replace after season start up, not season end.
Good Luck.
Bryan