Remanufactured vs Rebuilt Car Parts and What You Really Get

You need a new alternator, the parts site offers three versions at three prices, and the labels say "new," "remanufactured" and "rebuilt." Choosing wrong can mean doing the same job twice in six months, so it pays to know what remanufactured vs rebuilt car parts actually means before you click buy.

I have fitted all three types on customer cars and on my own, and the honest answer is that the label tells you less than the warranty, the brand and the part itself. Here is how to read those labels, which parts are safe to buy remanufactured, and where new is worth the extra money.

Remanufactured vs rebuilt car parts: the real difference

The two words get used loosely, but in the trade they are supposed to mean different things.

Remanufactured means the old unit, called the core, was fully stripped down, cleaned and inspected. Every wear item is replaced with new parts whether it looked worn or not. Critical dimensions are checked against the original specification, and the finished unit is tested to the same standard as a new one. For an alternator, that means new bearings, brushes, voltage regulator, rectifier and often a new pulley, followed by a load test on a bench.

Rebuilt usually means only the failed or obviously worn components were replaced. The rest of the unit stays as it was. A rebuilt alternator might get new brushes and a regulator but keep its original bearings with 120,000 miles on them.

Used or reconditioned can mean almost anything, from a cleaned and tested salvage part to something pulled from a scrapyard and sprayed with paint.

There is no universal legal definition that every seller follows, which is why the warranty is the most honest label on the box. A seller confident in a full remanufacture will put a long warranty behind it.

Parts that are usually fine to buy remanufactured

Some parts are built to be taken apart and rebuilt. Their housings rarely wear out; the parts inside do. These are good candidates for remanufactured units from a reputable brand.

• Alternators and starter motors. The most common remanufactured parts by far. A quality unit for a typical family car costs around 120 to 200 dollars against 300 to 500 for new OEM.
• Brake calipers. A remanufactured caliper gets new seals, a new or refinished piston and new bleed screw, usually for 30 to 70 dollars per side.
• Steering racks and power steering pumps. Expensive new, and remanufacturing replaces the seals that actually fail.
• Diesel injectors and turbochargers from specialist remanufacturers that flow-test or balance every unit.
• Transmissions and engines from established remanufacturers, where new is often unavailable or costs several thousand dollars more.

Most of these come with a core charge, a refundable deposit you get back when you return your old unit. We explain how to make sure you actually get that money in our guide to core charges on alternators and starters.

Parts where new is worth the money

Other parts are either cheap enough new that the saving is small, or wear in ways that remanufacturing cannot fully fix.

• Water pumps. New aftermarket pumps are cheap, and a failed remanufactured pump often takes the timing belt with it.
• Wheel bearings and hub assemblies. These are sealed wear parts. Buy new.
• Brake pads, discs and hoses. Always new.
• Sensors. Oxygen sensors, crank sensors and ABS sensors are rarely remanufactured well, and a bad one sends you chasing faults.
• Any part where the labor is huge. If fitting the part takes 6 hours of labor, a 60 dollar saving on the part is not worth the risk of doing the job twice.

A counter-take: "always buy new OEM" is bad advice

You will hear plenty of mechanics say that remanufactured parts are junk and you should always fit new OEM. I disagree, and the reason is where those new parts come from.

Many new OEM alternators and starters are made by the same large suppliers that run remanufacturing lines. Some carmakers even sell their own factory remanufactured units through dealer parts counters, with the same warranty as new. In those cases you are getting the same design, tested on the same kind of equipment, for a fraction of the price.

The real quality gap is between brands, not between new and remanufactured. A cheap new alternator from an unknown seller with a 90 day warranty is a bigger risk than a remanufactured one from a known brand with a lifetime warranty. We go further into how the OEM label can mislead in why genuine parts are not always what you think they are.

Where I do agree with the skeptics is cheap rebuilt parts. A 60 dollar rebuilt starter with a 90 day warranty and no brand name is only as good as one unknown person's bench skills. Spend the extra 40 dollars on a proper remanufactured unit.

How to check a remanufactured part when it arrives

Before you spend an afternoon fitting it, spend five minutes checking it.

1. Compare it with your old unit side by side. Mounting holes, plug shape, pulley size and the number of grooves must match exactly.
2. Spin it by hand. An alternator or pump should turn smoothly with no grinding or rough spots.
3. Look for a test tag or date stamp. Quality remanufacturers mark units as tested and dated.
4. Check the paint. Fresh paint over corroded threads or a cracked housing is a red flag. A clean, bead-blasted finish is a good sign.
5. Keep every bit of packaging. You will need the box to return your old core and to claim warranty if it fails.

If you are not sure the part is even the right one for your car, start with our guide on how to order car parts that actually fit and use your VIN, not just make and model.

Reading the warranty before you buy

The warranty tells you more than the description. Check three things. How long it runs, whether it covers labor or only the part, and if you must return the failed unit first. A "lifetime" warranty that requires you to pay shipping both ways and wait two weeks for a replacement is less useful than a 2 year warranty with an exchange over the counter at a local store.

Also keep your receipt with the car's paperwork. Lifetime warranties are usually tied to the original buyer, and you will not remember where you bought a starter motor four years from now.

Frequently asked questions

Is remanufactured better than rebuilt?

Usually, yes. A remanufactured part has all its wear components replaced and is tested to the original specification, while a rebuilt part may only have had the failed component swapped. The warranty length is the best quick indicator of which process was really used.

Are remanufactured parts as good as new?

From a reputable brand, a remanufactured alternator, starter or caliper often performs as well as new and comes with an equal or longer warranty. Quality varies more between brands than between new and remanufactured. Avoid unbranded units with very short warranties.

How long do remanufactured alternators last?

A good remanufactured alternator commonly lasts 5 to 8 years or around 80,000 to 150,000 miles, similar to a new one. Lifespan depends on driving conditions, electrical load and belt condition. Replace a worn belt and tensioner at the same time to protect the new unit.