I think I have found a way to do just that with the accessory belt tensioners on 850s or V70s (perhaps others too?) at a fraction of the cost of replacing whole tensioners or pulleys.
If the bearing in the pulley is the only part that is failing in your tensioner then why not just replace it for around $10?
With these steps below and some simple tools you can do just that. It took me half an hour to swap it out.
Tools required:
1) Steel or wood jaw vice
2) Point punch
3) 3/64, 13/64 and 19/64 high speed steel drill bits
4) Cold chisel
5) 3 Blind rivets 6.4 size as per photo (in steel not aluminium) and a pop rivet gun
6) some plumbing fittings, 1 inch water or gas cap end (perhaps a 20mm socket)
7) T40 torx bit
Step 1: Buy a 6203LH NTN brand or equivalent bearing
Step 2: Remove your tensioner (as this raises much heated discussion on the merits of coins, shaved down plumbing fittings and the like I won't go there
)Follow the steps below:
Re-assembly is a reversal of the above points with attention to ensuring there are no burrs on the facing belt surface. If so use a flat file and sandpaper to remove
Also once you insert the new bearing and re-assemble the two halves with the three holes lined up place the pulley b/w some wood blocks and belt it back together softly, then rivet the halves together, making sure it is pulled in tight by the rivets.
- Loosen the torx bolt with a T40 bit
- Centre punch back of the three rivets
- First drill a 3/64 hole in the punch mark
- Then progressively drill out the rivets with 13/64 and then 19/64 bits, then punch the rivets out
- Using a cold chisel work your way around until it separates
- Squeeze the bearing out with a vice (I used a plumbing cap & a large bearing on the other side)
- Your bearing is removed
- Use steel rivets for peace of mind