Removing bearings?
02-28-2006, 05:00 PM
#1
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Removing bearings?
Hi all, I'm having trouble removing the bearings from my old 3.5 K&B outboard nitro engine. I tried putting the PTO assembly and the head in the oven at 350 for 10 mins but they still wouldn't come out. Are there bearing pullers or any such tools for small nitro engines?
Thanks
-Alex
Thanks
-Alex
03-01-2006, 09:05 AM
#2
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RE: Removing bearings?
Heating the case in the oven should do the trick. Normally the rear bearing will come out with the crankshaft and you'll have fits taking the bearing off the shaft. The front bearing is simply pushed out from the rear once the crank shaft is removed. Try the oven again:
Remove the crankshaft. You may have to tap the front end of the crankshaft to get it out. Use a hard WOOD block or you'll damage the crankshaft. If the rear bearing stays in the crankcase, heat only the crank case at 350F for 10 to 15 minutes. With the case still hot, hit the back face (mount face to the lower unit) on a wooden block. Inertia will help push the bearing out.
Now you can tap the front bearing out from the rear side with a wooden dowel.
To reinstall the new bearings, mount the rear bearing onto the crankshaft.
Heat the crankcase and install the front bearing.
Install the rear bearing/crankshaft assembly into the heated crankcase. Don't push the front bearing back out. The front bearing serves as an alignment tool to keep the crankshaft and rear bearing square with the rear bearing seat in the crankcase.
Push the crankshaft in to seat the rear bearing.
Now that every thing is hot, let it cool and oil everything well.
Remove the crankshaft. You may have to tap the front end of the crankshaft to get it out. Use a hard WOOD block or you'll damage the crankshaft. If the rear bearing stays in the crankcase, heat only the crank case at 350F for 10 to 15 minutes. With the case still hot, hit the back face (mount face to the lower unit) on a wooden block. Inertia will help push the bearing out.
Now you can tap the front bearing out from the rear side with a wooden dowel.
To reinstall the new bearings, mount the rear bearing onto the crankshaft.
Heat the crankcase and install the front bearing.
Install the rear bearing/crankshaft assembly into the heated crankcase. Don't push the front bearing back out. The front bearing serves as an alignment tool to keep the crankshaft and rear bearing square with the rear bearing seat in the crankcase.
Push the crankshaft in to seat the rear bearing.
Now that every thing is hot, let it cool and oil everything well.
03-01-2006, 06:36 PM
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RE: Removing bearings?
I've had problems removing the bearing from the crank. Heating didn't help out. A bearing splitter and puller had to be used to remove the bearing.
03-01-2006, 09:39 PM
#4
My Feedback: (1)
RE: Removing bearings?
It's typical that the rear bearing is very tight on the shaft. I've never encountered the bearing staying in the case on a K&B 3.5. I don't think the intention is to remove and reinstall the same bearing so destroying it in the removal process is not an issue.
03-01-2006, 10:48 PM
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RE: Removing bearings?
Alex, didn't totally read your post first time around. I got a splitter off ebay: [link=http://cgi.ebay.com/ebaymotors/BRAND-NEW-Bearing-splitter-MPP-tools_W0QQcmdZViewItemQQcategoryZ35625QQitemZ46177 15817QQrdZ1]Ebay Bearing Splitter[/link]. You might want to look for a small gear puller also.
