I was searching around and I haven't found a specific answer. I'm trying to change the timing belt on my NA 2.5, SOHC. This picture apears to be the tensioner:

tensioner picture link (http://www.jeeptech.com/ForSale/050109/DCP_0835.JPG)

How does that thing work? Do I just remove the bolt on the bolt on the opposite side from the blue pulley?

Picture of everything else (http://www.jeeptech.com/ForSale/050109/DCP_0836.JPG)

I'd highly suggest that before you proceed further with this job, you should get a copy of the factory manual. That way you will have all the info you need to do this service.
You can get the manual from Subaru's tech site, here-
http://techinfo.subaru.com/html/index.jsp
Sign up for the $20/72-hour subscription and get whatever parts of the manual you need, or the whole thing.

First off, I second Mulder's suggestion.

Yes that is the T-Belt tensioner. It is a hydraulic type and needs to be compressed upon putting the new belt in.

There are two ways that I do this.

1. As the factory recommends (I think, I haven't looked at the service manuals for a long time.):

First remove the belts and what ever pulley you need to remove to ge the belt off

Remove the tensioner like you said off the engine and put it in a press, I used an upright 20 ton.

Slowly compress with the tensioner piston pointing up in small increments, don't go too fast or you'll blow it. And you'll see pin holes in the lip housing in relation to the piston.

Once you have compressed the tensioner to a point where the holes line up, put in a grenade pin thru it (or a paper clip of yielding size). Make sure you don't stick the pin too far in as it will interfere with putting it back on from the engine side.

Bolt it back in and when you are done with putting the new belt, linign up the marks, etc, and the pulleys back it, pull the grenade pin and check that the tensioner is working adequately.

Double check all timing marks, and all bolts tight.


2. And the other way that I fancy :) It might be confusing, so bear with me:

With everything still together, grab a large prybar and use the leverage from the water pump "pulley" to pry against it and the tensioner pulley gentily. You will see the tensioner compress and then stick the pin in it.

The belt will be loose. Remove the belt and proceed with what you are doing, etc. You won't have to take off the pulleys. After getting all the belts lined up, just lift the belt above the orange pulley, the farthest one down. Double check the marks and pull the pin.

Voila, you just saved a few minutes of work without removing the tensioner or pulleys and all that out-of-car compression. :)

SOHC's are pretty easy to work with.

-paK +4

I hope your water pump does'nt fail prematurely pak. That's probably not real good advise.

I hope your water pump does'nt fail prematurely pak. That's probably not real good advise.

It doesn't sound good, but it does kind of sound like something I'd try anyway.

This is a really easy job. I did mine on my 01rs not to long ago and I am more or less a novice of things. I followed the service manual instructions more or less. Remove the crank pulley, remove the plastic cover over the timing belt. Remove the tensioner pulley and remove the bottom left idle pulley. I recommend just compressing the tensioner in a vice and then sticking a paperclip or a small allen wrench through the whole to keep it compressed. Also something to note is that the service manual says that the notch count on the belt should be approx 40.5 and 44 if I recall correctly.....well this is wrong. If you get a new belt and count the notches it is more like 47.5 and 44. Just a heads up if for some reason you are using an old belt that has the alignment marks on it rubbed off.
To reassemble it first put on the tensioner pulley still compressed by your pin of choice. Then line up the two outside pulleys and the crank with the appropriate marks on the engine. Place the new timing belt on making sure everything is lined up. Once everything is lined up I recommend bolting on the cover over the crank to hold the belt in place on the crank for you. Now is the fun part of getting the belt on the two outside pulleys. Once that is done put the idle pulley back on and then pull the pin out of the tensioner. Place the plastic cover back on over the belt. Then the crankpulley goes back on. Put the car in 5th and have someone step on the brake pedal when you go to torque it. Put all your belts beck on and you are done. Hope this somehow helps. And yes you remove the top right bolt on the tensioner pulley bracket thing to remove it

I hope your water pump does'nt fail prematurely pak. That's probably not real good advise.

It hasn't yet. Nor has it on another car I worked on. :)

I figured the amount of axial stress caused by the belt itself far exeeds my press strength. I don't need to emphazise any excessive force when doing this.

-paK +1

Get the Haynes manual for the 1998 Legacy. It covers 98% of what is on your vehicle. It even explains the timing belt swap.