Subaru Wheel Bearing Replacment

I recently changed both front wheel bearings on my 2004 Subaru Forester. Aside from needing some specialty tools, the process is pretty straight forward. The three tools you’ll absolutely need are a hydraulic press, a bearing separator, and a set of bearing drivers (links to all the tool I mention are provided at the bottom).

YouTuber mikeatyouttube does a good job documenting the basic procedure. In fact, I relied heavily on on his video as a reference while doing the job myself.

Though it’s not so easy as it looks on YouTube. The bearing change out was the easy part to tackle, removing the steering knuckle and dealing with a defective bearing that made the job more difficult.

Removing the Knuckle:
I began by starting the driver’s side, long before I had the idea to record and document the process. On this side the halfshaft was frozen in the spindle, and no amount of pounding changed that. I ultimately used a three jaw gear puller to force the spindle out (don’t bother with two jaw pullers, they tend to just twist out and are nearly useless). In short, if you think you need a sledge hammer, reach for a gear puller instead.

Along the same lines ball joints can also be just as difficult to deal with. I had long been told to be weary of pickleforks as they can damage the the boot on a ball joint. So I opted for a Harbor Freight ball joint separator instead. Now, this worked… sort of. The fork on this tool is just a bit too narrow to fit around the ball joint, so I had to file it out with a metal rasp. Not much though, less than an eighth of an inch on each side was enough.

One more thing to watch out for is the top bolt that joins the knuckle to the strut. It looks just like a regular bolt when all put together. But it is cammed and adjusts camber. If you don’t mark it with something like a paint marker, you won’t know the proper orientation when it comes time for reassembly. I missed this detail and needed to take my car in for a front end alignment.

Defective Wheel Bearing:
Ok, so I’m cheap. I bought Duralast bearings. Given my experience, I wouldn’t go that rout again. One side went together fine. The other, however, persistently had play in it. The play in the bearing was only slight, maybe a millimeter at most. But when extended out by the diameter of the wheel, it became noticeable enough to be alarming. And this was after torquing down the axle-nut. The video below illustrates this play.

Against better judgment I tried the “press harder” approach. I ended up just pressing out all five wheel studs at the same time. It was at that moment when I decided the bearing must surely be defective. Sure enough, I bought a National brand bearing and it went back together tight with absolutely no play to speak of.

All in all, I’m probably out the same amount of cash as if I had just taken it into the shop. But I believe the experience is worth it, plus next time I need to press a bearing, I’m already set up to do it.

As an extra bonus here’s a video about how to get wheel suds back in without using a press:

Special Tools:
* Central Machinery 20 ton H-Frame Shop Press –

* Pittsburgh 3/4 in. Ball Joint Separator –

* Pittsburgh Large Bearing Separator –

* Pittsburgh 8 in. Three-Jaw Gear Puller –

* Pittsburgh 10 Piece Bearing Race and Seal Driver Set –

New How To Video

While in school I worked as a tutor for a few years. Since graduating last spring, this has been my first year without tutoring anyone. So after getting antsy, I’ve decided to try and make some YouTube videos about engineering. In my first video I talk about voltage dividers, and to derive a transfer function for one.

The Fiero Project


Some years ago my grandfather gave me an old Pontiac Fiero that had been sitting dormant for nearly twenty years. No precautions were taken to store or preserve it; it just sat outside in the elements with an undiagnosed engine problem keeping it from being moved. Once it was towed to my parents place, it sat in a garage for some years as I wondered where to begin with such a project. There where many obvious problems, and a lot needing fixing, from weathered and faded paint,and a broken windshield, to ancient gasoline in the tank, and the unknown engine problem. As I neared the end of earning a bachelors degree in Mechanical Engineering, I began to take the project much more seriously. Last summer I jumped right in and started by cleaning out the fuel system.

Starting with the basics, I turned over the engine by hand to make sure nothing was seized up. Next, I changed the fuel filter, as well as the oil and battery, which predictably did almost nothing; the engine turned over just fine but wouldn’t start. So, I jacked the whole car up and dropped the gas tank; which, by the way, was atrocious on the inside. After disposing of what was surely no longer gasoline, I hosed it out with a gallon of industrial degreaser . Followed by a good soaking with muriatic acid. I also tried using phosphoric acid, since the tank flash rusted shortly after the first cleaning. In my opinion it’s not really worth the fuss, the tank still flash rusted, and I don’t really like playing with strong chemicals. Now that it was clean I painted it and replaced the fuel pump ,and assorted rubber parts that had turned to goo.

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Before and after pictures of the inside of the gas tank.


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Before and after pictures of the fuel sender.



The finished fuel tank and fuel sender.


Now surely, I though, I should get something out of the engine; and I did. What I got was what sounded like an extremely rough idle before eventually stalling. Now I was getting somewhere. Following the advice of a friend I picked up a cheap compression tester, and tested the cylinders one by one. The fourth cylinder I tested had no compression. Next step: Engine Surgery. I popped off the valve cover, and voila! A jammed valve and a snapped pushrod. From what I can gather it seems an excess amount of carbon propped the valve in an open position. Then, with no force acting on the rocker arm to keep the pushrod seated it moved out of place, the rod jammed against it, buckled, and snapped in two.

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What I found under the valve cover (left), and the broken pushrod (right).

At this point I was pretty enthused, I finally had an excuse to rebuild a sizable part of an engine.  So I pulled off the cylinder head, and tore it down until it was bare. Then I packed it all up and cleaned everything in a chemical wash basin after hours at work. I honed all the valves, and replaced the one that had jammed. I took some time while everything was apart to paint the pushrod and valve covers fire-engine red with some spray on engine enamel.


By the time I got the head reattached, my dodge blew and intake manifold gasket, and since nothing can ever be easy on a Chrysler product, I spent the rest of what was left that summer dealing with repairs on my truck. Ultimately, I ended up getting it running well enough to trade in toward my Forester with 40,000 more miles and ten times the reliability. And so now I eagerly await this coming summer when I can finish reassembling the engine and test out the Fiero.