Durability of automatic transmission boxes versus durability of manual transmission boxes? Their lifetimes?

Auto transmission uses fluid to generate torque. That puts a little less strain on the components that are actually touching. And each gear has it's own "clutch"

Manual ones goes directly to physical contact. and there's one big clutch.

So the auto will outlast the manuals everytime. But when it finally comes time to rebuild it (remember, the clutches are in each gear) it's usually a $1000 to more.

The manual will burn the clutch faster*. but it's $200 and an hour in the shop to replace.

.* keep in mind this is all affected by several factors. so for one case you can have a manual lasting 150k miles and an auto lasting 50k miles... but it's two different cases that can't be compared easily. All that i said here is based on the most common designs and ignoring driving conditions/drivers.

Manual transmission BOXES last much longer than automatics. The clutches, however, vary with the driver. If the driver is good, then the manual is just as good as the automatic. If not, then the automatic's clutches will last longer.

This is true because there is at least one clutch for each gear in an automatic, and you can't replace them without rebuilding the entire transmission. You also can't normally operate the transmission if even one of them is unserviceable...they will cause the others to fail. Cost of rebuilding is $1000-$2500.

The manual has one large clutch. Replacing it requires temporarily removing the entire transmission. But good manual transmission drivers commonly have clutches that run over 100,000 miles (or even many hundreds of thousands). Cost of replacing a clutch is $450-$600. The clutch itself only costs $100-$150. The rest is labor.

The way to make an auto transmission last longer is to keep the fluid cooler. For most systems this involves a separate transmission cooler unit, possibly a cooling fan, and one of various types of transmission temperature sensor and gauge.

Yes. It is more expensive to maintain an automatic because it will eventually require fluid and filter changes which may not be within the capability of a Do-It-Yourself-er. The automatic will also be less fuel efficient in otherwise identical vehicles, by the very nature of the automatic's fluid coupling with the engine through the torque converter versus the manual transmission's physical coupling through the clutch.

You should note that Automatic transmission fluid change may not be required for the first 100K miles in some models. Materials in models that can be changed by a DIY-er usually cost $30-60 for fluid and about $20 for filter and gasket. For a shop to do it usually costs from $100-$300 (or even more) depending on the transmission.

But it is rare for an automatic to go much beyond 150K miles or so without a rebuild...because of the accumulated effects of heat on clutch material, soft parts, and normal wear on springs that most manuals don't have. The way to extend that time is by controlling transmission temperature.

So your friend is right, if we are talking about a driver who does not drive in a way that burns out clutches, and if he is going to keep the vehicle for a long time. Otherwise...it depends on how many clutches he burns out.

Or you might be right, if we are talking about stop-and-go traffic in an auto with a great transmission cooling system, or if you only intend to keep the vehicle for 30K or so miles as most people do.

I had a revelation after the manual transmission in my '97 Ford was replaced three times under warranty: Quality is more important than any inherent design advantage of automatic vs manual. As I see it, manufacturers make a lot of automatic transmissions and they put a lot of effort into making them reliable and durable. They don't sell many manuals in the US, so they don't put the development effort into them.

As a result, I got a series of bad transmissions until they finally put a stop ship on them, and a couple months later I finally got one that lasted over 100k miles. But even though this one has been "trouble free", it is still somewhat balky and sometimes doesn't want to go into gear on the first try, especially as it gets older. It's really embarrassing when you roar away from the light in first and then can't find second.

I see a similar thing with crank windows. Most cars have power windows nowadays, and if you find one that does have manual windows (like my Ford), they're cheaply made and don't wind as smoothly as they used to.

I've never worn out an automatic transmission, or a manual for that matter.

I'd say it depends on the car:

A 2003-2007 Honda Accord manual transmission replacement (i4 or V6), is going to run about 8-10 hours labor + parts.
You're looking at about a $2,000 U.S. expense. I know - ridiculous and frankly surprising but that's the consensus.

Then again, an Accord with an automatic transmission needs to have the timing belt & water pump replaced ~ every 100,000 miles. That surely would cost ~ $800-900 U.S. (My car has a timing chain - life of the vehicle)

Or, I get lucky and my clutch lasts for as long as I decide to keep the car. That's the ideal scenario. I'm not sure I'd get a manual trans. again - knowing the potential large cost, but we'll see.

It entirely depends on the car and the transmission in question and how they are used.

Some transmissions are insanely strong and some are delicate and some are just poorly designed or manufactured from the start. The reasons why are not always obvious. Transmissions are enormously complex in design and manufacture, and there are many ways in which they can fail.

At first glance, it depends how well the transmission is matched to the engine and the use of the vehicle. A car with a weak transmission and a powerful engine will have reliability problems. A car used for towing that isn't equipped with the means to resist the heat will have reliability problems.

However, a car with a high quality, well matched transmission can become unreliable if you change the power or the intended usage.

I have had a manual transmission last over 177,000 mi with the original clutch. Much has to do with driver ability. Semi trucks can go 500,000 miles and more on the same clutch with proper habits. The weak points on today's manuals are the master and slave cylinders. Slave cylinders which deactivates the clutch used to be mounted to the outside of the tranny and used a fork to push the throwout bearing. Now they are mounted over the input shaft which means you have to unbolt the tranny to replace as in the case with Ford. Master and slave cylinders have seals that can leak over time. With that said, there are still far less parts to maintain in a standard.

I bought a 1991 Nissan 240SX new with a 5 speed manual. I drove the car for 150K miles on the original clutch and it it was still fine when I sold the car. Many people do not know how to properly shift, and have never heard of double-clutching on downshifts. Aside from all the known arguments that manuals get better fuel economy, are more responsive, more fun to drive, faster, can be push started, offer better control in snow, and are less expensive to purchase and maintain- here's another. With so few people capable of driving a stick, it is an effective anti-theft device these days. While regular sedan type cars with manuals are less valuable on resale, this can be in your favor when buying. Furthermore, this ignores the fact that with collector cars, the manual is always worth more- a lot more in fact!

This question seems to assume that there is one kind of automatic gearbox. This is not true. There are at least five automatic gearbox types:

1. Conventional torque converter automatic
2. Robotized manual
3. Dual-clutch gearbox
4. Continuously variable transmission (CVT)
5. Hybrid electric CVT-like transmission

The problem with (1) is mainly that it wastes fuel, but newer models have improved on that. If (5) was not available, this would be my fallback choice, but unfortunately, at least in Europe, many manufacturers are using (3) and (4) a lot instead of (1).

Of the gearbox types, (2) is quite poor. Manual gearboxes are not usually designed to be used as robotized gearboxes. I wouldn't choose (2). Toyota used to use (2) after it switched to (4) (and (5), of course; Toyota has many hybrid models).

(3), on the other hand, is better than (2) when it works. Unfortunately, at least Volkswagen has had major troubles with their DSG dual-clutch gearbox.

Some people dislike (4) and (5) due to the fact that when accelerating, engine RPM is not linearly proportional to wheel RPM. Of these, (4) may cost a lot to replace if it breaks, and it is fairly recent development, meaning it may not be as durable as the variants that have withstood the test of time.

My solution? I choose (5). The hybrid electric CVT-like transmission is far simpler than any other manual or automatic transmission. It has the benefit of automatic transmission (no clutch to replace), without the drawbacks (fuel consumption), yet its replacement cost if something breaks is lower than that of any other manual or automatic. Also, it is so simple that it's extraordinarily rare that it would break.

So, my summary is that when comparing automatics and manuals, one needs to specify the exact type of automatic transmission considered. The answer is going to vary based on the automatic transmission type.