In your experience with this style tensioner RSPi, do you have to manually adjust the tension after you've unlocked it?

Or does the tensioner automatically set just enough tension on the serp belt after you've removed the locking bolt/pin?

 

This style of tensioner is quite common on almost everything these days is spring loaded and there isn't any way to adjust them. The spring is designed to apply the appropriate tension to the belt.
You don't have to use a lock (allen key) it's just easier than releasing all the tension and then taking up all the slack again when you're ready to put it back on. Most tensioners do not have a lock and you simply let the tensioner unwind to it's stop and then wind it up again when you put a belt back on.

On a Volvo stock tensioner they are serviceable !! In the manual they do recommend disassembly and lubrication of that spring mechanism every 30K.

NOTE: The auxiliary drive belt and automatic tensioner must be
removed from engine in order to properly lubricate.

Gdog, good catch. It looks like the alternator was never tested and we moved on to "can I replace it myself".

Rspi, thanks for the dimension

 

Thanks for the replies/tips.

Now, when I remove the tensioner can I disassemble/service/lube it myself or would it be better to get another? I'm at 120K with all accessories replaced.

 

I haven't taken mine apart but it looks easy enough to do. If you're not having any problems with it, I'd just grease it and reinstall it.