Dewalt MBF Motor Bearing Replacement

[jteneyck]

I finally received a set of bearings so I could put the motor back together.  Good luck if you ever have to send anything through the USPS hub in Indiana.  The first set of bearings arrived there and never left.  My local post office people traced it, sent emails to the IN facility, and even called me back after it was determined the package was lost and could not be found.  Very friendly and helpful, I must say, but the package nevertheless disappeared, and this was in November, not exactly the Christmas rush.  The bearing vendor refunded my money, so that was good, too.  I ordered more bearings from other vendors to avoid having to go through the IN facility and received them in another week or so.  

For those who might need to replace the bearings in a MBF, GWI, and probably other saws in this size range, the front bearing is 88504 and the rear one is a 88500.  Be aware, there is a short and a long 88500, the long one is the correct one, around 16.9 mm, IIRC.  

To start, I put the fan back on the motor arbor.  I tried to do it by freezing the arbor and heating the fan to 160F, but it wouldn't slide on, so I used a piece of aluminum tubing that fit onto the inner hub of the fan and whacked it a few times with a rubber mallet to seat it against the shoulder on the arbor.  



I installed the front bearing first, making sure I put the bearing retainer ring on the arbor first. This time, freezing the arbor and heating the bearing to 160F worked like a charm.  The bearing just dropped in place.  



I tried the same process with the rear bearing but it wouldn't go on, so I used a parallel jaw clamp to push it onto the arbor.  It took quite a lot of force to push it on.  With that done, I installed the shims and retaining clip against the front bearing.  



I put all of this back in the freezer and the front bell in the oven at 160 F.  As with the front bearing, the bell just dropped in place over the front bearing.  



I slid all of this through the motor stator and rear bell so that the rear bearing was centered over its recess in the rear bell and then whacked the front of the arbor a few times with a mallet to drive it in.  Everything looked good so I installed the four bolts to lock it all together.  Finally, I installed the ring on the end of the front bell, fishing the bearing retainer ring around until I could get the bolts to engage, then tightened them snuggly, backed them off, then snugged them again.  



The sound that caused me to replace the bearings is gone and the motor purrs now.  Now to get the motor reinstalled and get it all aligned.  My friend will be getting this just in time for Christmas.

[Tapper]

Too bad about the U.S. Postal Service. I'm expecting a package from them that is waaaay overdue and when I post the tracking # I keep getting the "status not available" response. I avoid the USPS like the plague when I can, opting at times to pay more for UPS or FedEx, but I digress.

Glad replacing the bearings solved the problem, and thanks for the photos. Good on ya John for gifting this to your friend - what a nice Christmas present!

Doug

[jteneyck]

Too bad about the U.S. Postal Service. I'm expecting a package from them that is waaaay overdue and when I post the tracking # I keep getting the "status not available" response. I avoid the USPS like the plague when I can, opting at times to pay more for UPS or FedEx, but I digress.

Glad replacing the bearings solved the problem, and thanks for the photos. Good on ya John for gifting this to your friend - what a nice Christmas present!

Doug

Go to your local PO and have them trace the package from the tracking number.  They'll be able to figure out where it is, or last was, and contact the appropriate location to see if it can be found.  Chances aren't good, but it's worth a shot.  

This is such a sweet saw it's going to be hard to give it up.  But I'm on the hunt for a Dewalt or maybe a Delta of 1-1/2 to 2 HP and with a long arm.  That would be my ultimate saw.  

John