Most car parts behave as a unit but consist of smaller parts inside. When these internal parts fail, the unit often requires replacement. If you do this yourself, you can save a lot of money, but you can save even more money if you diagnose which internal parts failed and change those rather than the whole unit.
Some examples include the following:
- Most Toyota control arms: they are giant pieces of metal with a big bushing at the back and a small bushing surrounding a stick of metal which bolts to the subframe at the front. The rear bushing usually goes bad over time. Although the control arm acts as a unit, it is technically made up of 4 parts. If you can change the wear items, you can save a lot of money.
- Alternators: they usually consist of a casing that comes in two halves, an outer coil, an inner coil/rotor, a shaft that spins, two bearings, and some electrical stuff. Common failures are the bearings and the brushes, which are part of the electrical stuff.
- Power steering pumps: they have several little fins inside that are spun by a shaft (on another shaft). There is a bearing and quite a number of seals, as well as a few rotating bits. Power steering pump failure is usually the result of low fluid causing the internal spinning parts to grind, leaking seals, or a worn bearing.
- Axles (FWD): they consist of an inner and outer universal joint, a shaft, a boot that seals in grease on each side, one protrusion that connects to the transmission, and another that passes through the hub. Common failures are the boots, which get old and crack, spilling grease out and letting dirt in, and the universal joints after long usage.
- Power steering racks (non-electric): they consist of several seals, bearings, a few guides, a pinion, and a large shaft. Outer tie rods attach to each end of the shaft. Common failures are the seals. In fact, I think that’s pretty much the only thing that ever goes wrong with these, unless you’re really unlucky. If you count the tie rods, those do wear over time.
So, you can change your control arms and save money. Or your alternator, or your power steering pump, or your axles, or your power steering rack. You can save a lot of money doing this. But, as I’ve mentioned, the cause of failure in these units is typically due to a few very specific internal parts, usually items that simply wear out with age, such as seals, boots, and bearings. If you can take these units apart and change those, you can usually preserve their life much longer for a fraction of the price. But there’s a catch: you have to be able to get those units open, and you have to be able to change the appropriate parts without destroying the unit.
Now, I can tell you from experience…changing the unit is far easier than changing the internal parts, which is often referred to as “rebuilding”. Most Haynes and Chiltons manually do not walk you through the rebuilding process. Almost every part I’ve attempted to rebuild, I’ve managed to destroy the first time around. Fortunately, I usually had the foresight to know there was a good chance this would happen, and bought junkyard parts for the attempt. Goodness, am I happy I’ve done that.
First car. Power steering pump. I used a socket along the center of the bearing to hammer it back in. It crushed the thin metal casing onto the ball bearings inside, rendering them ineffective. Thank goodness I bought that one for $13 at the junkyard.
Knuckle assembly. Wanted to learn how to press wheel bearings out. Bent the knuckle in my shop press because I forgot there was a snap ring that holds the bearing in place. Dumbass move, but a lesson worth $20.
Axle. Was incapable of removing the shaft from the outer universal joint. Smacked it with a 5-pound hammer many times to no avail. The axle was already destroyed on the outside, so the only downside was not being able to swap a better part in.
Alternator. Recently bought a junkyard one online to see how hard it would be to pull apart. Turns out it is stupid difficult to do, at least for my car. Somehow pressed the outer coil out on one side that shouldn’t have been. The shaft simply refuses to come out of the bearing, and in the process I managed to shatter part of the metal casing trying to use a puller. And the back piece simply isn’t designed to be removed. I’m still wondering why the shaft won’t release, as the official shop manually says nothing about that being press-fit.
The moral of the story is, rebuilding is way more challenging than replacing. But the lure of rebuilding is that you can save more money. The problem is that it requires more skill, and often specialized tools. I was able to pull my old power steering rack apart, but I could afford to be careless because I knew I was going to throw it away afterward. Putting that back together properly would have been a huge challenge. So yes, the $130 OE rebuild kit seems like a sweet deal compared to the $650 price tag for the OE rack, but don’t think for a second it’s going to be fun.
This is why people who rebuild transmissions specialize in rebuilding transmissions. You can charge a lot of money for it because it’s such a critical part that can’t cheaply be replaced. There really aren’t any shops that specialize in rebuilding alternators, power steering pumps, axles, etc, because there is so little money to be made in this. The only people who do this are the companies that specifically sell remanufactured parts. It takes time to replace a part, but it takes even longer to rebuild that part once it’s out of the car, and when you have to charge a customer time to rebuild the part, that eats into the savings they expected for having the part rebuilt in the first place!
The best savings to be had for rebuilding parts is to do it yourself. However, you have to ask yourself whether the extra time it takes to rebuild something is worth the savings. That power steering rack example seems like a pretty sweet deal, unless you get into it and find that the other, non-replaceable parts are worn out or damaged. The sad truth is, it usually often works out that replacing the unit as a whole saves an awful lot of hassle. It’s tempting to chose the rebuild route, but if you screw up, you end up spending more in the long run, and that’s no fun.
I’m kind of bummed about the alternator. It seemed like a perfectly fine alternator, and I kind of wish I had bought an absolute shit unit so I could tear it apart, rather than tear apart something that looked like you could slap it in and it would run for the next 5-10 years just fine. But it was still about as cheap as it gets online, and there’s no guarantee it actually worked. Just because it looks pretty doesn’t mean it runs, but I have no reason to suspect I need a new alternator either, I just wanted to learn. But mind you, it occurs to me that even better than being able to rebuild parts is the ability to properly diagnose them when they are bad. The most expensive thing you can do to your car is throw parts at it trying to fix an issue. The worst way to throw money out is to replace your alternator thinking that’s the problem, only to spend several hundred dollars and find out that didn’t fix anything.
But you know, part of me is just not content to leave it at that. There’s something really cool about being able to pull something apart and understand how it all works, fix the issue, and properly put things back together. It did happen with the powersteering pump: that was a successful rebuild, and all it cost was like $30-40 in seals and the $13 for the junkyard unit. I really love learning this stuff, and it won’t be the last time I buy some junkyard parts to pull apart. But learning costs money. That alternator was almost $70, so I understand there is a weird catch-22: you learn to save money, but it costs money to learn. So at this point I think I’m firmly in “I want to learn anyway” territory. It’s sure cheaper than college classes, so that’s my justification. There are probably some things I can realistically rebuild and other things I can’t, but I’d at least like to try my hand at it and find my limitations.
(Side note: wrenching a part from a junkyard yourself is a lot cheaper than buying online, but I think my car is one of the most popular vehicles in history, and whenever one of these arrives in the junkyard, it is picked clean within several days. So yeah, I could try to drive 40 minutes north just to realize there is no way in hell I can find the part that I want, or I can pay extra for the labor somebody did to pull it themselves, list it on eBay, and pay the shipping for something that weights 30 pounds. Honestly, there is a good chance that you come out ahead just ordering it on eBay, even if it costs a little more. But that depends on how common your car is and how likely it will be picked over by the time you make it to the junkyard)