4th Gen SOHC 2.5 Timing Belt Replacement - Pic intense

Ok, so, I took the time to document the timing belt / water pump / thermostat / accessory belt replacement, so if it'll help one person its worth to post. The car is an 2006 Legacy 2.5i, SOHC, MT with 104,533 miles, but I assume this should work for nearly any 2.5 SOHC from the late 90's on? I have more time than brains, so it took two weeks (!) of a couple hours per night more or less. Before this, my mechanical experience was just the basic maintenance stuff (oil, spark plugs, etc).

The pictures below are the highlights, all the pictures are here.

Preparation, parts list, tools
I got all my parts from Advance, online, two different orders, utilizing their coupon codes. I spent about $250 shipped to my door. Not too bad, but I know there are better parts around. Remember this is a 2.5i, I need it to commute not race.

1. Qty, P/N. Description
2. 1, 95307K1 Dayco Timing belt replacement kit
3. 1, 5050345, Dayco Power steering belt
4. 1, 5040333, Dayco A/C belt
5. 1, 160-2090, GMB Water Pump w/gasket
6. 1, 143-0710, Beck-Arnley thermostat
7. 1, TCS 46008, Camshaft seals (not used)
8. 1, TCS 46009, Crankshaft seal (not used)

Tools recommended in crazy order: 3/8" socket set with 10, 12, 14, 17, 21(?)mm sockets, extensions, metric wrenches, drain tub for coolant, LOTS OF RAGS, breaker bar (bigger the better), radio, strong back, jack, jack stands, snack bags, pen, paper, camera, shop light, flash light, gloves, pliers, another person every now and then, big ass torque wrench, small ass torque wrench, feeler guage, mirror, ST 49997710 (or equivalent)

I don't like to rush myself, so luckily I have another car I can drive to/from work. Thats another reason it took so long, driving a 280Z daily in the summer time is not a bad thing. Plan accordingly...maybe a long weekend?


Timing belt removal
Those vacation pics are so inspiring! I highly suggest you look at them first before attempting this, even print out the best pics and have them on hand while working.

Disconnect the battery. Jack up and support all four corners with jack stands. I put a stand under each pinch point, but I guess you could do the same under each frame rail.


Remove the under body covers (x2 one on each side). My coolant hadn't been changed since new, so I wanted to flush it anyway. Then I saw how much room I'd have to work with, so I just decided to remove the radiator. Wait for the engine/radiator to cool. Unplug the radiator fans (x2, one on each side). Open the radiator cap and the overflow tank, then drain the coolant via the drain plug on the radiator. Take a bath, curse, fight the urge to drink the sweet nectar, then take a picture of it.

Remove the coolant hoses at the bottom and top of the radiator. It's easier to remove the radiator with the inlet air box removed, so remove it.

Remove the over flow tank. Remove the radiator and all the disgusting things stuck in between the a/c condensor and radiator. It should look like this afterwards...


Remove the accessory belt covers. Loosen the tensioners and remove the belts. Remove the a/c tensioner.

Now comes the fun part, removing the crankshaft pulley. I've searched a bunch, and you'll find the same thing. The general consensus for removing the crank pulley is by the 'starter method'. Get a socket that fits, stick a breaker bar on there, make sure its against the ground or frame, then bump over the starter to break the crankshaft pulley bolt free. I really don't like that idea, no matter how many times it works for other people...I'd be the exception that breaks something awfully expensive.

I didn't have the ST 49997710, but I did have some scrap wood, bolts, washers, cordless drill, and a jigsaw. So I made my own ST, and let me tell you, it worked like a charm.


Next, remove the timing belt covers, I found that unplugging the oxygen sensors made it easier....don't forget to reconnect them at the end! With the covers off, you can see what you're up against.


With the cover off you'll need to line up the timing marks; one on the crank, and one on each of the cam gears at the top. I loosley put the crank pulley and bolt back on to turn the engine over until the marks lined up. Take a silver sharpie, or paint pen, and make marks on the belt.


Remove the belt guide, idler pulleys, then remove the belt. Remove the auto tensioner. Keep the belt, I suggest you use it later...



Water pump / thermostat

I ordered new camshaft and crankshaft seals based on someone's (I forget, sorry) recommendation, but I didn't use them. The vacation pics say to remove the camshaft gear to remove the water pump. However, this took another ST 18231AA010 or 499207100 tool to remove each, and I was all out of ideas to make one, so I gave up after I read this post...thanks Silverstar. I ended up not replacing the shaft seals.


Remove the tensioner bracket. Take care to not ruin any gasket material. Remove the water pump.


Remove the thermostat cover. Clean it up. Install the new thermostat in the new water pump. Double check and clean the new water pump. Install the thermostat cover. Install the new gasket material on the outside of the pump. Prepare to install the assembly.


Install the pump, check it moves freely. Reconnect the little coolant hose.


Timing Belt Installation

Compare the old belt (left) to the new one (right). My old belt looked good.


My Dayco kit came with a new auto tensioner and idler pulleys. Intall the tensioner bracket, along with the new auto tensioner. Don't remove the grenade pin yet.


Here is where I deviated from the vacation pics. I tried it their way first, but I just didn't have the strength to stretch the belt around the toothed idler near the water pump.


At this point I realized I shouldn't be messing with the new belt until I figured it out, so I used the old one. I found that installing the toothed idler near the water pump first, then installing the smoothe idler on the left side of the crank gear last really helped. You can put enough pressure on the belt and at the same time not worry about tooth engagement, just screwing it on.


Once you have that figured out, remove the old belt and install the new one. Check the new timing marks line up just the same as the old. Once you think you're good, remove the grenade pin. I wanted to check engine rotation to make sure nothing was binding. Remove the battery and the spark plugs so its easier to turn over.


Install the crank belt guard, make sure there is clearance clarence with a feeler gauge. Clean and reinstall the timing belt covers.

Next is the crank pulley reinstall. Clean and oil the bolt and pulley. Get your big torque wrench, ST tool, and a degree wheel (forget the name). Tighten the bolt and check the degree angle of tightening. Vacation pics says 65 to 75 degrees, I got about 60 after the second try. So...like an idiot...my breaker bar made the extra 10 degrees or so, we'll see how long that lasts. Don't try that at home, do it the right way.



Belts and Accessories Installation

Install the a/c tensioner, and the new belt. Tension the belt, you can get close by looking at the clean part of the tensioner screw. Same thing for the power steering belt.


Reinstall the belt covers. At this point in time I installed new spark plugs, then reinstalled the battery. Honey badger doesn't care though, you can do what you want.

Clean the radiator as best you can, an air compressor helps at lot, then install it. Same thing for the over flow tank. Reconnect the radiator fan connectors. Don't forget to reconnect the oxygen sensors if you unplugged them.


Reinstall the air box. I clean it all up and installed a new air filter.

Reinstall the radiator hoses, upper and lower, and tighten the drain screw. Stand back, breathe, and grab some new coolant. Fill the radiator slowly then fill the over flow tank. Start it up and rev a couple times, then shut down. Open the radiator and fill it up again. Wash, rinse, repeat. Also, tapping the hoses will release some air bubbles.

Warm it up completely and wait until the fans turn on then off. Shut down and let cool. Once cool, top off the radiator. Wash, rinse, repeat. Done.

Lesson learned

Keep all bolts and notes in a snack bag, number them in order of removal. Keep all parts removed in one area if possible instead of setting them all over the place.

Its nice to have an OBD code reader. A friend told me about a $20 bluetooth one on eBay, and it works great. You can download the Torque app for free to check and clear codes. Its awesome. Thats how I knew my oxygen sensors were unpugged once I started it for the first time.


Hope that helps someone. Have fun.

Hats off to you. Great DIY post!

Thanks for the kind words. I posted this then I realized there's a Walkthrough section, maybe I should have posted it there? Can someone move this for me?

Yes. Contact a Mod. SBT or Tide can do this for you.

Nice walk-through. Very thorough and well-detailed.

Moved to Walk-through and edited title to ensure everyone knows that this is 4th-gen related.

Hi all, I am new to this forum and wasn't sure where to post this...
My question is...
Is there any special procedure for the tensioner like leaving it set vertically for a period of time before installing it or "priming it" by rotating the engine by the crank sprocket before starting the car? (I read the FSM and couldn't find anything like this)
I ask because after installing all new OEM parts my tensioner did not expand when the pin was pulled although the belt felt tight. In fact, when the car was started the tensioner began to knock against the tensioner bracket. Is this simply a bad tensioner?
Any help is appreciated and thanks!
FYI it's a 2005 Legacy n/a SOHC

Originally Posted by pb&j

Is there any special procedure for the tensioner like leaving it set vertically for a period of time before installing it or "priming it" by rotating the engine by the crank sprocket before starting the car? (I read the FSM and couldn't find anything like this)
I ask because after installing all new OEM parts my tensioner did not expand when the pin was pulled although the belt felt tight. In fact, when the car was started the tensioner began to knock against the tensioner bracket. Is this simply a bad tensioner?

I installed a new non-OEM tensioner, and it didn't expand like I imagined it would when i pulled out the pin (similar to what you described), maybe the new belt was tight enough already? What's interesting is the old tensioner took me by surprise and expanded quickly while removing the old belt. Once installed, I did crank over the engine by hand many many cycles to prove to myself it would work. Thats not to say I knew what I was looking for, just that there were no tight spots nor mechanical interference noises.

Maybe someone else can tell their experiences? I don't know enough to say it is right or wrong.

I have done timing belt jobs on several different types of cars (not new to timing belts) and I thought the belt was tight enough on this without the tensioner plunger expanding much, if any. But the tensioner was knocking against the bracket and that sort of sounds like piston slap... annoying... plus there's the damage to the parts to think about.
Just trying to figure out what is going on. I compared all the old pulleys to the new ones and they are all 60 mm in diameter as expected so I don't have any pulley that is wrong. Also, the toothed pulley has the correct number of teeth. Tensioner is identical to the old one. Belt is correct Subaru part number and correct length.
I have a new tensioner on its way to me... Hopefully this will fix it.

...and new the tensioner is a fail. Time to try a new belt... since I find it hard to believe that I would get 2 brand new tensioners that are dead.

Yup I just installed my dayco kit and surprise surprise. 30 miles down the road the belt skips. Checked where it skipped and the only logical answer is the brand new tensioner. my passenger side cam is about 4 teeth off from top dead center. Sounds very bad. Going to have to set it back to top dead center and see if I bent any valves....... My advice is buy an OEM tensioner

i wonder if ill have this issue with the gates timing kit. i bought it from fred beans, and subaru even lists it as being a "performance" upgrade to their own kit.

^ gates timing kit worked fine. drove about 85 miles on it so far and no issues with the tensioner.

Also used your guide and the vacation pics and it was pretty simple. friend and i spent about 6.5 hours on it, probably about 30-45 minutes of that was making a st10wood aswell, and another 1 running back and forth to the store.

^Good to know, I bought the Gates timing kit and water pump as well.

How do you make sure the crank pulley is correctly indexed when reinstalling? I don't see a keyway which is the typical method?

It does have a keyway, only one way it will go on.