Sealed Swing Arm Bearing Question

[Jeff in W.C.]

I reinstalled the swing arm and preloaded the bearings. The up-down motion was smooth with no notchiness; however, there seemed to be a minute amount of side-to-side play, which reminded me that the rear seemed a little loose a few times since I brought it out of storage. As such, I think it's best to replace the bearings since thing are apart. FYI, there's no play in the final drive (I had it rebuilt about 10k miles ago), so I'm sure that's not the issue. Thanks for everyone's help.

[barryh]

I reinstalled the swing arm and preloaded the bearings. The up-down motion was smooth with no notchiness; however, there seemed to be a minute amount of side-to-side play, which reminded me that the rear seemed a little loose a few times since I brought it out of storage. As such, I think it's best to replace the bearings since thing are apart. FYI, there's no play in the final drive (I had it rebuilt about 10k miles ago), so I'm sure that's not the issue. Thanks for everyone's help.

If you pre-loaded the bearings and they are correctly seated, there can't be any side to side play that's due to the bearings themselves. It must be something else. They really are taper roller aren't they ?

[Rob Frankham]

I reinstalled the swing arm and preloaded the bearings. The up-down motion was smooth with no notchiness; however, there seemed to be a minute amount of side-to-side play, which reminded me that the rear seemed a little loose a few times since I brought it out of storage. As such, I think it's best to replace the bearings since thing are apart. FYI, there's no play in the final drive (I had it rebuilt about 10k miles ago), so I'm sure that's not the issue. Thanks for everyone's help.

If you pre-loaded the bearings and they are correctly seated, there can't be any side to side play that's due to the bearings themselves. It must be something else. They really are taper roller aren't they ?

+1...

If there is any side to side movement and it doesn't change depending on radial position of the swing arm (i.e. how far the swing arm is lifted), then the bearings aren't properly adjusted. The next question is "are the threads for the pivot pins clean so that they turn freely in the frame thread. Any resistance will affect the setting of the pre-load. It may be necessary to take the pins right out and clean up the threads.

If the side to side movement varies over the travel of the swing arm then, yes, the bearings are damaged and will have to be replaced.

Rob

[RPGR90s]

maybe post a video of the play you are describing.

[Jeff in W.C.]

If the side to side movement varies over the travel of the swing arm then, yes, the bearings are damaged and will have to be replaced.

Rob

The side-to-side movement I felt was subtle and not over the complete travel of the swing arm. (RPGR90s, a video would not show any side-to-side movement.) I checked side to side movement while moving the swing arm up and down. Perhaps they are fine, or maybe just a little out of spec. I've decided to change them because things are completely disassembled and there's really no addition labor-just the cost of the bearings. There's a tech day coming up this Saturday, and I plan to replace them at the tech day. A local guru will be there with this tools and his advice. I don't think I can go wrong here.

This coupled with the fact that the rear end felt a little loose a few times over the 6-12 month time frame before I took things apart. I think it's time and money well spent to rule out the bearings.

[jackonz]

Interesting, as a mechanic and maintenance engineer and reading all of this it sounds like the pivot pins have not been tightened correctly at installation, if it were me I would be using the unsealed bearings and greasing them with a grease gun on a regular basis

[Jeff in W.C.]

Long story short, it ended up being a good decision to replace the bearings. They were brinelled.