Chain Case Bearing Seal Question

[prostock700]

I have a 1999 sx 600 and was wondering why the chain case bearings have the seal in the bearing? would'nt it be better to remove the seal and let the bearing run in the chain case oil?

 

[98srx6]

This has long been debated here. Some say run the seal on the inside, some say run it on the outside. If you do a search on it, your likely to find alot of reading material on the subject.

 

[TJ500]

run the seal on the chaincase oil side and have it removed on the tunnel side.. this is how Yamaha does it.....

 

[change_up]

If you've ever seen what metal shavings will do to an open bearing, you would know which way to put the bearings in!! lol. I would run my seal to the chaincase side and the open side to the tunnel. The seal still lets oil seep into the bearing and keeps the metal debris out. A good way to test this theory is to put a small bit of oil on the seal in a bench vise, and take a drill and spin the inner race of the bearing, you will see the oil being sucked into the bearing through the seal.

 

[Ding]

Yes, take a close look at your oil when you drain the chaincase. Rub a little bit between your fingers. You do not want that oil in your bearings as it will simply grind them up causing premature failure. It is important to use the right style bearing seal so that the seepage of oil occurs like change_up indicated above. There are many different types of bearing seals and bearing seal materials. Just use the right numbers for the bearings and you will be good.

 

[bluemonster1]

I am changing my bearings today on the chaincase.Yamaha bearings were installed sealed side of bearing to the inside of chain case and open side of bearing to the tunnel side.Now my new bearings are sealed both sides.You are then telling me to open up the one side and place it towards outside(tunnel side) .Change_up is this ok or should I leave the new bearings with both seals on?

 

[change_up]

Personally I would leave them both on. Then you are keeping the oil in the bearing and also helping to keep snow dust out of the bearing as well as the metal debris from the other side. Like I said if it were ME doing it I would leave both seals on there, but i've been wrong before.

 

[bluemonster1]

Thanks man!!

 

[TJ500]

if you are changing bearings you should be changing shaft seals too on the drive and jackshaft.... $3 each! with new shaft seals, dirt won't get in from the back side and then you can remove tunnels seals on bearings just as Yamaha has engineered it to be....

tj