lundi 5 avril 2010

02 YZ250 - Changing front wheel bearing

After engine has been modified, I've been doing a general checkup on the bike and found out that the front wheel was wobbling left to right (1mm) but it was anoying. I've decided to remove the wheel using the following steps :

Removing the wheel
- Remove plastic brake cover (10mm bolts if I remember correctly)
- Remove the nut that holds the wheel shaft between the forks
- Loosen the nuts that retain the forks to the shaft (4 bolts, 2 on each side)

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Remove the shaft by carefully hitting on the threaded side (I used a box that was the appropriate dimension to remove the shaft). Careful not to messup the outside and inside threads, they are both valuable.

Removing collars
Remove collars and remember which one goes on what side. The one with a curved end should go on the front disk side.

Removing the oil seal
Using a screwdriver, pry the oil seal out of the wheel. To avoir prying using the wheel's rim, I've dropped a box on it's side and used it as a leverage point. It should pop out right away. You should change the oil seal but I've decided to keep it cause it didn't seem to be damaged.

Removing the bearings
I did not have access to a puller and wanted to change the bearing pretty quickly. Here are the steps :
- find a long flathead screwdriver
- Using your finger, move the bearing to remove so it's unaligned with the center spacer
- From the opposite side of the wheel, aim for the bearing with the flathead and hit with a rubber hammer to get it out.
- 6-7 good hits will get it out of there
- Repeat for remaining bearing

Installing the bearings
- At the dealer, I've decided to take the NKN version of the bearings. They were actually cheaper than OEM and they were sealed (See in the picture the difference between the old and new bearings)
- Add lithium soap grease as described in the service manual (you'll see the blue grease in the picture)
- Insert bearing in the wheel, place a 28mm box over the new bearing and tap with rubber hammer. The bearing should sit pretty easily. Make sure you don't hit on the inner race of the bearing, it will damage the bearing.



Reinstall oil seals
Push oil seals and add lithium soap grease on the lip

Reinstall collars
Pretty straightforward if you remembered where they were at removal

Reinstall the wheel shaft (it is suggested in the manual to grease the shaft). Here, it was greased using the lithium soap grease seen in blue.

1 commentaire:

  1. This is how a proper bearing maintenance should be made. And you showed it nicely too. Very detailed. Nicely done.

    tilt pad bearings

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