Driveshaft bearing installation on Tower of Power

[merc1250bayliner]

I am wondering how difficult should it be to install a bearing and driveshaft race into the hole in the gearcase? My original gearcase failed because of corrosion so I somehow managed to find a never been used case. Well tragically I cracked the brand new case while driving the bearing race into the hole. So as frustrated as I am I was able to locate yet another case. How difficult should this bearing and race be to install? Thinking that it could be the wrong bearing I tried it on my original case and it goes in without excessive force. Could the new case of had a casting flaw? Maybe I should of ground down the bearing so it didn't go in so hard? Too bad I didn't have some sort of specs so I could use a dial indicator to double check what the bore of the hole should be. I just don't want to destroy another case. These things are not easy to find.

Also, some of my confusion with this bearing is that in the Selloc (yes I know) manual it shows the bearing being put in with the race first. But I have seen it otherwise online where you use a shim, then spacer, then bearing, then race.

[wolfgangb]

In most cases, the driveshaft bearings sitting above the pinion (if needle/cylindrical roller type) are tapered and must be installed with the lettering on the bearing case facing up. Needles/rollers must be in, as they transfer the force which is exerted by the puller mandrel, into the bearing casing. Even if it is the correct bearing (onus is on you to make sure), it is good practice to freeze the bearing and heat the gearbox casing. Put Mercury Extreme Pressure Grease on outside of the bearing casing or into the bore to help it into the bore and avoid scoring of the bore surface.
If bearing is tapered roller type (typically Timken), shim goes in first, then race, only then loose bearing cage with rollers. Stick driveshaft thru bearing from top, position pinion on splines, install washer and nut (Loctite only after backlash has been correctly set), torque to spec.

[W2F a V-King]

If you don't have the tools to set up gear lash and contact pattern, you will be $$ ahead to take it to someone who does, and knows how to set it up properly.

It's not just a matter of pulling the components and putting them in a new housing, or another used housing. Those shims are used to set backlash and contact position/depth.

It has to be right or it's a time bomb to failure.

[Dave S]

Or ya could PM Dave S. and he will send you a 20 inch case for shipping.........

[Dave S]

I have had cases that I used Jap bearings and had problems..... ya shouda not cracked a case.....Will look at my stock for you....just I move slowly.....