Wednesday, September 21, 2011

Keeping the Old Forester Going: DIY Belt Replacement

Earlier this year, I started doing a lot of the maintenance on my car myself--more out of a sense of, "if you want it done right, you've got to do it yourself," than necessarily to save a few dollars, though the latter is nice, too, given the typical mechanic charges more than double what I make per hour.  One of the first tasks I tackled was flushing the power steering system, which solved a multitude of problems--but eight months later the steering started acting up again, this time with an audible squeak I hoped was only the pump drive belt and not the pump itself going bad.

Drive belt cover removed to show the power steering
 & alternator belt (left) and air conditioner belt (right)
I've got nearly 90,000 miles on my 2004 Forester XT, and though I've been pretty good with the upkeep, it's nonetheless eight years old.  The steering system had really started to squeak when I first started the car, and the steering wheel had started vibrating again along with the car idling a bit rough at times like it had before I flushed the fluid (don't get me started on how Jiffy Lube had put the wrong fluid in--yeah, I know Dexron III is labeled as transmission fluid and not steering fluid, but that's what Subaru designed the car to take and that's what should be used!).  Replacing the pump would set me back around $150-$400 in parts, depending on whether I went with the OEM or an aftermarket pump, so I figured I'd first try replacing the belt and flushing the fluid again.

I don't believe drive belts are supposed to look quite like this...
The existing drive belt definitely needed to be replaced: as you can see in the photo above, it had split along the length of the belt into three sections, and was starting to fray along one of the strands as well.  I'm actually a bit surprised my battery held a charge, given the same belt drives the alternator and obviously  wasn't working very well, as it was slipping and squeaking a good bit.  The fact the belt is hidden away beneath a cover is no reason I shouldn't have caught this sooner (nor an excuse Jiffy Lube shouldn't have noticed it during one of their services).

Getting the right replacement belt was harder than the replacement itself.  My understanding from much consultation with the Internet tubes is that the generic aftermarket belts from auto parts stores don't quite fit right compared to the OEM ones, and unlike most parts debates across Subaru forums, almost everyone agrees on that point.  I drive right past a Subaru dealership on the way to work, so figured I'd stop in and that their service department would have something like that in stock, but alas, they "were at the warehouse," already closed for the day--and come Monday, the same tech greeted me with the same line he'd given me a few days before: "Oh, I've got some bad news on those belts... they're at the warehouse."  Yep, closed for the day again, too.

The delay pushed back the repair until after I got back from a trip to Vegas with my sister (that's a long story involving a skinny ginger git from Harry Potter and worthy of its own blog post).  Facing a commute to the office with a seriously-deteriorated belt, I decided to tackle the job before going into work.

Under the hood with the belt cover still in place
For the 2004 Forester XT, the accessory drive belts are located beneath a plastic safety cover (pictured above, foreground).  This comes off with the removal of two bolts--have a ratchet with metric sizes on hand, and you'll have no problems getting it off and out of the way.

Bolts which need to be loosened to remove the power steering & alternator drive belt (red circles)
Even split and as worn as my belt was, it had plenty of tension and wasn't about to slip right off.  I could have cut it--the existing belt wasn't exactly in great shape anyway--but given the new belt installation requires getting things loosened up, there's no avoiding releasing the belt tension.  There are three bolts for the power steering and alternator drive belt (which are mirrored for the air conditioner compressor drive belt); I've circled them in red in the photo above.  The two leftmost bolts are called out in the service manual and serve to tension the belts--to adjust, first loosen the bottom bolt a few turns, as it locks the entire assembly in place, then turn the top bolt to move the alternator up or down and thus increase or decrease the belt tension accordingly.

Before you get too far and wonder why the belt doesn't seem to be getting any looser, here's something my service manual neglected to include: notice the third bolt (center right, above)?  You have to loosen it as well so that the alternator can pivot as you adjust the long bolt on the left; a half turn or two is all it should take.  I had to really lower the alternator to be able to get the old belt out and the new one in, running that long bolt nearly all the way out.

While you've got the power steering and alternator belt out of the way, you should go ahead and replace the air conditioner belt, too, as belts tend to show similar wear, and you can't get to the a/c belt without first removing the power steering one.  The tensioner is similar to the one for the power steering and is located just to the left of the air conditioner compressor (the thing with the big pulley on the right of the image above).

Once the new belts are in place, just reverse the process you used to loosen the components and relieve the belt tension in the first place.  The belts should be tightened until they displace about a quarter of an inch under firm pressure, something you can measure by putting a straightedge between the pulleys and then pushing the belt down with one finger while measuring the distance it moves down with a small ruler (easier said than done).  Don't forget to tighten the bolt which allowed the alternator and compressor to pivot down.

I did the change-out in about 10 minutes before going to work one morning, so it should be easy for anyone to accomplish.  No special tools are required--just a socket wrench--and the parts aren't particularly expensive (both belts together set me back around $25 from a local Subaru dealership).  Replacing the belts eliminated my car's squeak, smoothed out the steering system, and should be good for another 90,000 miles or so.