Subaru Timing Belt Facts
- Subaru 2.5 DOHC and SOHC are interference engines
- Subaru timing belts are due for replacement at 105K
- Oil will shorten the life of your timing belt
- The water pump should be replaced with the timing belt
When replacing the timing belt on a Subaru 2.5L SOHC or DOHC motors there are a few common things to look for and I have some tips to help you get through the job even if you don’t have the factory tools. If you’re interested in buying factory tools Subaru uses Kent Moore for their specialty tool manufacturer. Otherwise keep reading for some quick and easy Subaru timing belt tips and tricks.
What to look for when replacing a Subaru timing belt
Subaru timing belt recommendation is at 105K but it’s not common to have to replace the timing belt before this mileage due to oil leaks from either the cam seal’s or front crankshaft seal. There are other spots to check such as the oil pump and the large piston access 12mm allen head bolts in front of the block also leak oil sometimes. Now as far as the rest of the components go I almost always recommend the water pump to be replaced due to mileage and there are a few timing belt idler pulleys you need to inspect for bearing noise. If any of these pulleys don’t spin smooth or make bearing noise when you spin them then replace them. There is a cogged idler pulley that bolts to the water pump and I always recommend this pulley with the water pump just because this is the first one to go out because of the load it has from the belt. The other pulleys are not under as much tension so they’re usually good for a while. Last you need to inspect the timing belt tensioner for bearing wear on the pulley and also inspect the hydraulic portion of the tensioner for leakage. If the hydraulic fluid were leaking from the tensioner I would replace it. I have re-used them this way before but unless your experienced with the tensioner these tensioners hold on the belt I wouldn’t gamble, this is an interference motor.
Now it’s time to get to the timing belt to inspect all these parts we know now to look for. First challenge, break free and remove the front crankshaft pulley. Now these bolts are very tight from the factory and require a lot of torque to break them loose. How are you going to hold the pulley from moving to break it free? You could use the special Kent Moore tool or just take a breaker bar and 22mm socket on end of crank bolt, wedge the breaker bar next to the battery and crank the motor over. I would remove the battery hold down and place something over the transmission cooler lines to protect them if they’re present. Take a look at this pic to get a better idea:
Now you have the covers off and your ready to start taking off the timing belt. Before you get ahead of yourself you need to break loose the cam gear bolts and this is done best with the timing belt still on. Get a couple clips and attach them to the belt/gear to prevent the belt from jumping when breaking free the bolts. Now reinstall the crank bolt and turn the motor till the timing marks align. Install a 22mm wrench to the crank bolt and wedge it up against the alternator pulley. You can now break free the cam gear bolts with a breaker bar or whatever.
Replacing Subaru Cam Seals
So, you need to change the cam seals, water pump, inspect the timing belt tensioner and idler pulleys for wear and replace as needed. Most of these parts are sel explanatory for replacing except for the cam seals. You’re probably wondering how to remove them. We’ll there are lots of different techniques yu could use and I’m not going into detail about that because there are just so many different ways you could get them out. I use an actual cam seal puller.
I used to use a pick too, but no matter how you decide on how to remove them just be careful not to scratch the camshaft because it can cause the seal to leak. Not too long ago I had a customer in with an oil leak that was just that, he scratched the camshaft while removing the cam seals so just be careful.
Subaru Timing Belt Tensioners
The last thing I will tip you on is how to compress the hydraulic tensioner for the timing belt. All you really need is a decent bench vise that opens far enough to fit the tensioner in it and slowly compress the tensioner careful not to force the piston; you will fell the tension release after a short wait with each turn of the bench vise. Once the tensioner is compressed all the way use a small long allen key and slide through the lock pinhole. The picture below shows a compressed tensioner using the factory lock pin, which if you buy a new one it comes this way so you wouldn’t have to worry about compressing the timing belt tensioner at all but they’re not cheap. As faar as replacing the tensioner just inspect for bearing noise from the pulley and leakage from the hydraulic cylinder, either of those and you should replace the timing belt tensioner. I have seen Subaru timing belt tensioners go bad and make noise like an engine knock.
That pretty much sums up all I have for now, if you like the article leave me a comment or ask a question. I’m always happy to answer them. Don’t forget to like my page too, thanks.