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HELP! Mark 58e Driveshaft Removal

J

jay.krause01

New member
A friend gave me a 1958 Mercury Mark 58e, very cool looking engine by the way. It supposedly sat for 3 years before he gave it to me, and it sat for another year before I got it running, which was way longer than needed. All I had to do was repair the distributor and it fired up like it hadn't been sitting more than a week.

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The problem is the water pump wasn't working. I pulled the lower unit and the cap for the impeller. The groove for the pin that holds the impeller around the driveshaft is chewed up. There's a small chunk of the driveshaft missing.

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I have everything disassembled as far as I can get it, but I can't get the driveshaft out. I'm hoping to mill a new groove on the other side of the driveshaft to keep the impeller in place. I would much rather mill a grove for a woodruff key rather than a small pin, but I don't know if there is an impeller that will fit. I have the the screw removed from the bottom of the driveshaft that holds the pinion gear on, but I cant get the darn thing to slide up and out. I've tried using a slide hammer to pull it out, but I'm afraid I'm going to brake something if I get any more aggressive. It does freely turn, but it feels and sounds like there's a bearing that needs replaced. All the gearing and shifter components look amazing. Hard to believe this thing is 63 years old. There is also a type of cup that the impeller sits in. It looks like it may unthread from the lower unit housing, but there's a set pin holding that in that I also can't seem to remove.

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If anyone has any idea how to continue this adventure please educate me, I am at a complete loss at this point.
 
Remove screw / nut from bottom of driveshaft.----Then put driveshaft in a hefty vise.----Use a block of wood and hefty hammer and bump gearcase away from the vise.
 
First soak the area around the waterpump cartridge with a penetrating oil for a few days, clean the area around the threads then put the driveshaft horizontally into a vise and tap on the housing gently with a mallet or hammer protected with wood. The key will come out with the cartridge. You can use heat to help loosen it but not too hot. There's a possibility that the bearing might be damaged even if not - replacements are available. I wouldn't cut a woodruff key slot just a flat for a pin; check the seal surface on the driveshaft for grooving if it is grooved a SpeediSleeve can fix it.
M58-impeller.jpg
 
racerone said:
Remove screw / nut from bottom of driveshaft.----Then put driveshaft in a hefty vise.----Use a block of wood and hefty hammer and bump gearcase away from the vise.
Click to expand...

I do have the screw out of the driveshaft. I have basically been doing this the other way around. I have had the gearcase in a vice and was using a slide hammer on the driveshaft. I did switch it up since I can get a little more muscle on a small sledge over a slide hammer. Still no luck.

Quicksilver said:
First soak the area around the waterpump cartridge with a penetrating oil for a few days, clean the area around the threads then put the driveshaft horizontally into a vise and tap on the housing gently with a mallet or hammer protected with wood. The key will come out with the cartridge. You can use heat to help loosen it but not too hot. There's a possibility that the bearing might be damaged even if not - replacements are available. I wouldn't cut a woodruff key slot just a flat for a pin; check the seal surface on the driveshaft for grooving if it is grooved a SpeediSleeve can fix it.
View attachment 26903
Click to expand...

First, great exploded parts view. The only one I have been able to find is barely legible.
I have soaked it in the past though I did soak it again last night. Like I told racerone, I did try switching it around and hitting the case with a small sledge, using a block of wood of course. No movement at all. I did however think that the impeller cartridge threaded in. It makes more sense that it doesn't. Though I still can't seem to get it to budge. I'm putting a good bit of force on this thing, which I am very worried about. I really don't want to crack the housing.

It dawned on me today that I've had this engine for 2 years not 1. It's been apart in my garage for the last year and a half while I have been messing with it off and on. Mostly trying to remove this driveshaft. Trying not to get discouraged.

Thanks for the tips but this thing is still solid.
 
Pour boiling hot water on the bearing / pump cartridge area while using the slide hammer.----Anybody / shop in your area with hydraulic jacks ?----The kind with a hole down the middle.----My local fix it shop has them.
 
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This may require a lot more penetrating oil and higher heat or put grease around the shaft area and use a Dremel type Moto-tool to cut a new groove, then wipe away the grease.
 
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I gave it another go today. Still no luck. This thing solid. I'm beating on it so hard I'm afraid I'm going to crack the aluminum housing. I guess I was hoping there was another retainer screw or clip I was missing. I'm honestly surprised that it is stuck like this. I know it's old, but it's in amazing shape, fired right up, and everything seems to move with ease. I do like the idea of soaking it in diesel fuel for a couple of days. I guess I'll just keep at it.
 
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