How the #@%! do you get this bearing off??

[Grumpy Bear]

While I have the powerhead on my 74 Merc 500 50hp cracked open, I thought I would replace the seals and bearings in the upper and lower end caps of the crankshaft. I got the lower cap off just fine, but I'll be a son of a gun if I can figure out how to get the bearing out of the thing (see pics). So, I have 3 questions:

(1) Is there some special tool I need to get this off? (I'd hate to buy a tool to use once, but hey...)

(2) When I reinstall, I assume the bearing needs to be installed in the end cap before putting it back on the crank? I've seen other engines where the bearing is installed on the crank (after heating it) then the end cap just slides over it, but I don't think this one is installed or removed that way. Advice?

(3) I assume I'll need to use Merc's specific flywheel puller to get to the top bearing?

Thanks in advance for your help!

Kevin

 

[Chinewalker]

Put the cap, loosely, in a vice, bearing side down. Heat up the outside of the cap with a propane torch, working around the perimeter. Bearing should fall out due to aluminum expanding more than the steel of the bearing. Heat up the case again when reassembling and (cool) bearing should slip back in. Take care not to cook new seals with torch and work with thick gloves. Nothing worse than forgetting for a moment and picking up a hot part!!

 

[Grumpy Bear]

Thank you for the advice! I would presume, then, that the whole thing should be re-heated when reinstalling on the crank? Or, I wonder if I should heat the bearings, seat them on the crank, let them cool, then heat the housing and slip it on the crank and over the bearings?

 

[Chinewalker]

No, do NOT heat the bearings. They are steel, as is the crankshaft, so there is no advantage to heating one or the other. They should be a slip fit, or light press at worst. Only heat the aluminum casting of the bearing housing, install that bearing, then install the assembly onto the crankshaft.

 

[Grumpy Bear]

No, do NOT heat the bearings. They are steel, as is the crankshaft, so there is no advantage to heating one or the other. They should be a slip fit, or light press at worst. Only heat the aluminum casting of the bearing housing, install that bearing, then install the assembly onto the crankshaft.

Got it. Thank you. I kind of figured that since it came off fairly easily.

 

[merc850]

Don't forget to oil the seal lips when installing so they don't run dry at startup.

 

[Grumpy Bear]

Don't forget to oil the seal lips when installing so they don't run dry at startup.

Thanks for that reminder!