It has been brought to my attention that the automatic tensioner for the auxiliary drive belt must be
greased every 30,000 miles (45,000 km) or if an abnormal
noise is heard from the tensioner.
The auxiliary drive belt and automatic tensioner must be
removed from engine in order to properly lubricate.

The above lifted from the 850 Volvo maintenance information pdf. No, I have never greased the tensioner. I am not sure what weight grease should be used, I am sure Volvo would let me purchase it for a small donation. Then, again, the failure rate for the tensioner roller bearing is quite low.

The timing belt tensioner roller bearing is also supposed to be greased when changing the timing belt. Heck, I just change out the roller every 70K miles.


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Keeping it running is better than buying new

Can those tensioner bearings be greased? I’m thinking in terms of an early V70, where the roller looks to be a sealed unit and is simply replaced as Klaus suggests.

Disassemble and repack with grease, similar to a wheel bearing?

It looks like there are 4 grease 'holes', the bearings cannot be removed and 'packed'.

Sounds like an exercise in futility to me. Once the bearings make noise, they are pretty shot. I just change them out when I feel it is time, at least at the 120K mark.

Beware of the special clip which can only go on one way. A poor design.
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Keeping it running is better than buying new

If you have a newer aux belt, get a wear gauge from the Gates site.

There you will see that newer serpentine belts do not crack like older belts but wear out like tire treads and will slip especially when wet.