'72 45HP Chrysler impeller change

[kauboy]

Hey guys, been a while since I visited since my last boat got water damaged and is inoperable ATM...

Well, my father said I can use his flat-bottom if I can get it running.
As the title states, it's a 1972 Chrysler 45HP Model#: 457HD.

Not knowing how long it's been since any maintenance has been done, I started with the basics. I know it runs, just want it to run right, ya know?
I ordered a carb kit for it and took care of that.
The next thing is the impeller.
I couldn't find a whole kit for the impeller through iBoats, so I just got the impeller itself.
$23 :-0

For my questions:
Should I even attempt this without a new gasket for the housing?
Is it possible to use a gasket maker for this?

Also, will Frank's instructions on impeller changes apply pretty closely to mine?
His was for 3 and 4 cylinder engines, and mine's only a 2.

Finally, do I need to worry about the shift linkage at all with this year model?

Thanks guys.
I appreciate any help you can give.

 

[Frank Acampora]

Re: '72 45HP Chrysler impeller change

The 45 is actually simpler to change than bigger engines: Only 4 bolts on the leg and six small ones on the rear shrouds--You need to remove the starboard side to access the shift linkage.

Been a long time so I don't remember exactly, but if you can not find a gasket, it is simple to make with an exacto knife and child's hole punch. The only things that may give you a problem are the water pump screws. They may be corroded and may also be slotted heads. A difficult combination

The shift rods have a lot of bends in them so there is some compliance. Thus, you do need to be accurate when reattaching them. The jouning hex coupler is opposite threaded on either end like a turnbuckleso turning one way will shorten the shift linkage and turning the other way will lengthen it.

 

[kauboy]

Re: '72 45HP Chrysler impeller change

Thanks for the response Frank.

Sorry I didn't get back in time, but I could have saved you the typing, haha.

A mechanic buddy and I set our minds to it and started working on it.
We dropped the lower unit just enough to notice the shift linkage at the bottom.
But, we could only tighten or loosen the two jam hex nuts.
So we figured that couldn't be the right spot.
We tucked the whole thing back up and got on the phone with my aunt's dad (the former owner).
This man knows his motors!
He had never done this work on that particular engine, but gave us the little jewel of info we were needing.
The same info you gave.
That housing cover needed to come off to take apart the linkage.

Once we got that, it was pretty much cake from there.
We dropped the unit, loosened the water pump bolts, which were hex heads and in pretty good condition.
That's when we ran into a problem. At the top of the driveshaft was a rubber boot, and a metal ring. The boot just slipped off, no sweat, but we couldn't figure out how that ring came off. Not being sure, we didn't force anything.
We were still able to lift the housing and check the impeller, which was actually in really good condition. No cracks or damage of any kind. It wasn't brittle at all. The fins were just bent, like always.
We cleaned everything we could and also found that the gasket was metal, so we cleaned it up really well and just reseated everything.
I do think I'll have to change the shaft seal under that gasket soon. It looked a little ragged.
There was no indication of gear oil coming through, so I figure it should survive the one trip we have planned.
I may still check and change the oil before this trip. Not a big job at all.
I assume it uses the same "premium" oil as most lowers, right?

So we just closed it all up, fought a bit with the linkage to work it back in, and had everything done in about 2 hours. Not bad for amateurs, lol.


The only question I still have on it would be concerning that ring on the driveshaft.
The impeller will no doubt need replacing eventually, but we won't be able to get it off with that ring in place.

Any suggestions?

Thanks again!

 

[kauboy]

Re: '72 45HP Chrysler impeller change

Does anybody know what to do with the ring at the top of the driveshaft?
I can't changed the water pump without removing it.

Also, is the gear oil the same as most lower units?