Reliability, or the lack of it in the systems we use.

redplumber

To begin, this is somewhat of a rant about the quality of parts we use, but also a request for general advice

My story starts about 4 years ago when we decided it was time to invest in a new steam heating system to replace the aging system. We got a few estimates and ultimately chose to replace the system with an identical system: Peerless 211A-08-S-I (1470000 BTU input).

The installation went well, everything was new, and they said even some near boiler piping was "fixed". All good.

Almost immediately (within a few weeks), we had a small problem: the boiler would fill with water. It would fill up way above the top of the sight glass. I would have to drain many gallons of water from the system to see the top of the water level and to restore heat again to the property.

The installer gave me a laundry list of reasons why this could happen, but considering that nothing really changed other than the boiler, I told him it must be something with the boiler. He came out to look at it, but ultimately said it's nothing they did.

By chance, the boiler displayed the problem right in front of me! It started filling with water. We then focused on the water feeder pump. The installer said that it's not the first time he's had problems with this pump.

At a later time, the boiler did it again! This time, it did it longer: it wouldn't stop feeding water into the boiler. I looked around, trying to figure out what was happening. I started tapping the feeder pump thinking something was stuck. By chance, I tapped the end of the McDonnell & Miller No. 67 Low water cut-off which immediately shut off the water feeder pump. Bingo!

When the installer came next, he still insisted that it must be the feeder pump, even though I told him what caused the feeder pump to stop. I believe he sent out someone to "look at it" twice with no success. When a third gentleman at his company came out, I explained to him exactly what I did. He went to his truck and replaced the mcdonnell miller switch 309100.

This fixed the problem for the season, but not completely. It filled with water once or twice, but it was mostly resolved compared to how bad it was at the beginning. The next heating season (last winter), the issue kept cropping up again. Maybe 2-3 times a month. Not horrible, but definitely a problem.

This year I decided that I must fix this myself (mostly because the installer said that it's not his problem). I went to mcdonnellmiller.com and pulled up the service parts catalog. I located what I thought was the part that failed and searched online. When I saw how expensive they are, I was a little shocked. How can a part so simple, yet so expensive, fail so horribly?

Luckily, I had all of the parts from the old system in storage. I disassembled the old McDonnell & Miller No. 67 Low water cut-off, removed the part, and compared it to the new one installed on the system. Here is a picture (newly manufactured one is on the left):



The only difference I notice is that the old one (that we had no issues with for MANY years) appears to not have any markings of "CHINA". I installed the old switch and haven't had any issues so far this heating season. None.

I have another recent experience (in 2021) where 2 of 4 richmond water heaters (made by rheem) had failed gas valves. One of these had to have the gas valve replaced once and then the whole heater had to be replaced on the second failure because they ran out of the gas valves (that are failing faster than they can manufacture them).

This leads me to the following conclusion:

- Whenever replacing anything, save your old equipment
- Just because something is commercial and expensive, it doesn't mean that the parts within it aren't cheaply made

and this leads me to the following question:

How do you choose quality manufacturers (or controls, systems, units, parts, etc.)?

EBEBRATT-Ed

@redplumber

You can'r. It's all junk.

Someday this country will maybe figure out that we need to stop buying from China and other countries where quality control means nothing.

But people want everything cheap and complain about prices already so they do their shopping at Wal Mart

We are our own worst enemy's

Jamie Hall

As kind of a general rule, you can have quality and reliability or low price, but not both at once (note that you can have high price and poor quality both at once, however). Why? Both the labour to construct the device or machine and the materials to construct it with cost money.

And the plain fact of the matter is that the modern consumer wants low price and glitz above all else. If the manufacturer wants to sell to that market, they have to cut the cost of manufacture (glitz is cheap; any fool can throw a few chips and an LCD screen on something, raise the price a couple of hundred, and laugh all the way to the bank). There are only two ways to do that: move your manufacturing to somewhere where you get value for money (granted, not much of either one, but you meet the price point) or invest in robots -- which only works if your production runs are very large.

pecmsg

Please post several pic of the near boiler piping. Try and get 1 shot with everything in it.

delcrossv

So i see the problem has spread from major appliances to heating equipment. I guess it's endemic.
It's pressure from the bottom on price. Use cheap suppliers and stay in business another day. Until the "disposable lifestyle" comes to an end, we're stuck.

+1 for @EBEBRATT-Ed . He nailed it.

hot_rod

It really comes down to who is operating the factory and the quality control measures they enforce. The major German boiler folks have been manufacturing in China for years, but they manage the quality control part. Same with every automotive manufacturer, circuit boards come from China for the most part.
Overseas manufacturing...that ship has sailed.

Generally with China, the first batch is excellent, passes all the cycle and accelerated wear procedures, orders from then on tend to get value engineered, if you do not pay attention..

The motto "everyday low prices" started a trend, didn't it. Even though that brand no longer uses that marketing approach.

The machines and people that control manufacturing can reside anywhere, poor quality knows no borders as does excellent quality.

Steamhead

They were using a #67 to operate a feed pump, instead of a valve on a water feeder unit?

Major no-no. You need a #150 pump controller to do that. Even the American-made switches would fail when used that way.

JUGHNE

I would use a motor relay, such as a 2 pole AC contactor rated for 30 amps and then use both poles if 120 volt. Should last a long time.
Replacement could be kept on hand for less than $20.

Jamie Hall

A little comment sort of inspired by @hot_rod 's comment. I would agree that one can, in fact, get much the same quality anywhere -- in principle. But what is sometimes forgotten is that different cultures (and hence nations) have very different philosophies when manufacturing things, and this is hard to overcome. Two examples -- quite irrelevant to heating -- come to mind. Consider aircraft gas turbine engines. The US and Europe create and build engines to exquisite tolerances with almost incredible reliability. The Russians are quite capable of that, but they'd rather save some money on first cost -- and their engines are powerful and cheap to build and maintain, but have miserable reliability and longevity. The other is the AK-47 automatic rifle. The build quality is atrocious, and they don't last long, but they run, if they run at all, in any conditions you care to name -- while an M-15 is much better built and lasts a long time if it's not abused, but drop it in the mud and you have a long cleaning job ahead (don't ask me how I know0.

JakeCK

Jamie Hall said:

The other is the AK-47 automatic rifle. The build quality is atrocious, and they don't last long, but they run, if they run at all, in any conditions you care to name -- while an M-15 is much better built and lasts a long time if it's not abused, but drop it in the mud and you have a long cleaning job ahead (don't ask me how I know0.

Heck, I've heard an AK shoots better with some mud in it. Tightens up the tolerances. lol

That reminds me, I need to get in the safe and clean all my rifles. I haven't been to the range since this virus started and they haven't been getting much attention as a result.

JUGHNE

I recall reading about the siege of Stalingrad in WW2.
The Germans learned of the disadvantage of very close tolerances they had in their finely built weapons.
At about -40F (or C the same), their rifle barrel metal shrunk to where the ammo would jam.
The Russians with rather loose tolerances were able to continue firing.
The Eastern Front was not a good place to be for the Germans.

And the Japanese used rifle ammo rounds that were 1 point larger than ours.
They could use our ammo but theirs would jam in our rifles.
It was all in the plan.
War trivia as I heard/read about it.

delcrossv

Relevant to this, just had a 2 year old HWH by a well respected maker fail yesterday. Thermocouple wire was angled to be in the burner flame- toasted to a crisp. That unit was assembled here. Poor QC can be anywhere, but I have to agree there is a cultural element to slapdash.

The Steam Whisperer

McDonnell and Miller has been making mostly junk for several years now. It's pretty obvious that even in the residential steamer market, I don't think anyone is using McDonnell and Miller electronics anymore, it is all Hydrolevel. Lots and lots of problems.

Daveinscranton

I hate stuff that breaks.  Hate it.  I recognize that everything is made to a price point.  I upsize relays routinely by a factor of 5 or 10.  Whatever is in my parts bin. USA made.   Lots of electrical surges etc where I live for whatever reason.  I also add ammeters liberally, panel volt meters, indicator lights etc.  When something is going south, I may have an early indication.  If not, diagnostics are easier.  Pretty hard to do this if you are in business and still make a living.  I am not in business so not an issue.  The internet turns up deals.  And I can be a pack rat.  Comes in handy.  I also like quality fittings.  And sometimes pipe that is a wee bit oversized.  And isolation valves.  And drains.  And vents.  Takes the misery out of bleeding air from hydronic heat.  There are several things I have never heard.  Like: “ I wish I had used less gravel for drainage.  I wish I had used less insulation in the house.  I wish I had not used the rich concrete mix and rebar in the footers.  I wish I had run lighter gauge wire.  I wish I hadn’t used oxygen barrier pex for my hydronic heat. I wish I hadn’t used so many pipe supports/hangers.  I wish I had put the rafters on 24” centers rather than 16” centers”  It goes on.  Never heard it.  My friend in the concrete and stone mason trade and I talk about it.  He makes a great living fixing other people’s self inflicted messes.

ChrisJ

Daveinscranton said:

I hate stuff that breaks.  Hate it.  I recognize that everything is made to a price point.  I upsize relays routinely by a factor of 5 or 10.  Whatever is in my parts bin. USA made.   Lots of electrical surges etc where I live for whatever reason.  I also add ammeters liberally, panel volt meters, indicator lights etc.  When something is going south, I may have an early indication.  If not, diagnostics are easier.  Pretty hard to do this if you are in business and still make a living.  I am not in business so not an issue.  The internet turns up deals.  And I can be a pack rat.  Comes in handy.  I also like quality fittings.  And sometimes pipe that is a wee bit oversized.  And isolation valves.  And drains.  And vents.  Takes the misery out of bleeding air from hydronic heat.  There are several things I have never heard.  Like: “ I wish I had used less gravel for drainage.  I wish I had used less insulation in the house.  I wish I had not used the rich concrete mix and rebar in the footers.  I wish I had run lighter gauge wire.  I wish I hadn’t used oxygen barrier pex for my hydronic heat. I wish I hadn’t used so many pipe supports/hangers.  I wish I had put the rafters on 24” centers rather than 16” centers”  It goes on.  Never heard it.  My friend in the concrete and stone mason trade and I talk about it.  He makes a great living fixing other people’s self inflicted messes.

There is a such thing as going too far.
There's a good way to engineer and build things and then there's the extremes in both directions, neither are good.

My house has rafters 24" OC and I have no complaints about it. There's no roof sag and it does the job it was intended to.

JUGHNE

If you were around a hardware store in the 50's, there was a bargain bin of cheap tools. They were all stamped "Made in Japan" and prone to certain failure.
That term was applied to many things that were considered very inferior.
You would avoid anything made in Japan, except chinaware.

Jump ahead 20-30 years.

Every GI wanted their cameras and stereo systems. (I still have mine).

When Milwaukee came out with early (9.6 IIRC) battery drills, and we thought they were great.
The early good ones were made in Japan, including the batteries.
Milwaukee then started production in this country and quality and reliability dropped.
Enough to make one go to the blue tools, still made in Japan.

Jump ahead to today, I don't think we would pay for the quality that Japan may produce. IDK, as I don't see any of their tools.

Also, they are now the largest auto producer in this country, just knocked GM down a notch.

A big step from the Hondas of the early 70's.

ChrisJ

MikeAmann said:

Not in all arenas, but yes, Japan (and China) is fully capable of producing quality like what MADE-In-USA used to stand for. Know why? We gave them the technology.

Like the cars of the mid 70s-80s?

Jamie Hall

Much as hate to admit it, many of the things we use and have today are actually more reliable -- at least by some measures -- than what we had when I was a young man. Curiously, some things are a lot less reliable. And it's kind of fun --and quite pointless! -- to speculate on what and why.

Consider cars. How many people younger than say 40 have ever changed a tire? How many of their cars even have a spare tire to change? 100,000 miles on a tune up? Or 6,000 to 12,000 miles for an engine oil change? Granted the older machinery will run pretty much forever, given proper care, and much of the newer simply can't be cared for (if it breaks, you replace it -- the engine control module, for instance). It is much the same with larger home appliances -- or heating equipment! -- and it is all the more remarkable in the face of the far greater complexity and capability of some of the newer stuff.

At the same time, though, there is an almost overwhelming amount of consumer grade stuff being made, sold, and junked almost as fast as we used to change socks. Items which, as the country saying goes, are all sizzle and no bacon.

Things to think about...

ChrisJ

Jamie Hall said:

Much as hate to admit it, many of the things we use and have today are actually more reliable -- at least by some measures -- than what we had when I was a young man. Curiously, some things are a lot less reliable. And it's kind of fun --and quite pointless! -- to speculate on what and why.

Consider cars. How many people younger than say 40 have ever changed a tire? How many of their cars even have a spare tire to change? 100,000 miles on a tune up? Or 6,000 to 12,000 miles for an engine oil change? Granted the older machinery will run pretty much forever, given proper care, and much of the newer simply can't be cared for (if it breaks, you replace it -- the engine control module, for instance). It is much the same with larger home appliances -- or heating equipment! -- and it is all the more remarkable in the face of the far greater complexity and capability of some of the newer stuff.

At the same time, though, there is an almost overwhelming amount of consumer grade stuff being made, sold, and junked almost as fast as we used to change socks. Items which, as the country saying goes, are all sizzle and no bacon.

Things to think about...

At the same time, though, there is an almost overwhelming amount of consumer grade stuff being made, sold, and junked almost as fast as we used to change socks.

That's primarily because it's been drilled into people's heads that new is better.
It has absolutely nothing to do where things are made and it has nothing to do with the younger generations. This started a long long time ago and they worked hard at making it this way.

Look at the cost of repair parts alone, they often are priced so it can never make sense to repair and the manufacturers don't want you repairing things.

ChrisJ

MikeAmann said:

Not in all arenas, but yes, Japan (and China) is fully capable of producing quality like what MADE-In-USA used to stand for. Know why? We gave them the technology.

Like the cars of the mid 70s-80s?

My Dad worked for General Motors. In the mid-eighties, the powers-that-be walked the foreign car manufacturers right into the plants and showed them how it's done. They took that information back home and did it faster with much cheaper labor. Now we can't compete.

What did your dad do at GM?

DanInNaperville

In China, all land is owned by the local government and is sold as a lease to whoever builds on that land. At the end of the lease, the local government gets the land back (and the building) and gets to sell it to someone else. It's their primary source of revenue (vs. the property, income, and sales taxes we have).
Residential land leases can be for as long as 70 years, but can be shorter, and the local government can sometimes re-write the lease conditions. Buildings, even skyscrapers, generally have a design life of 40 years. https://en.wikipedia.org/wiki/Property_law_in_China
Who wants to buy a house with 40 years left on its land-lease? In 20 years, you won't be able to sell it for anywhere near its original value, since it will only have 20 years left. So buying a house or apartment that's more than 30 years old isn't a great idea. That's got to permeate the culture, to some degree.
Industrial land leases are supposed to be for 50 years, but if the local government decides it wants to switch from shipbuilding to chemical plants, say goodbye to your factory investment.
https://economictimes.indiatimes.com/news/international/business/s-korean-shipbuilding-giant-shifts-out-of-china/articleshow/87220203.cms?from=mdr There are always many reasons for moves like this, but the area with the shipyards was incorporated into an expanded chemical manufacturing zone and the shipyards were "encouraged" to leave. Now the local government gets to re sell the land lease and collect more revenue.
That may be part of why Chinese companies just don't see the point in making things to last indefinitely. It doesn't make sense to build anything to last in China since it will be taken away.

At the same time, there's no honest stock or bond market so people put their life savings into buying homes because there's really nowhere else to invest savings. But they aren't stupid and know that's not a great situation to be in. It's really unfortunate for the people forced to live there.

So they're depressed (for good reason!) and get sloppy at work, on top of the stuff not being designed to last.

Solid_Fuel_Man

As I've worked on many cars from all over the world, and on much industrial machinery also from all over the world. I've come to discover that....as much as I hate to admit it.....country of origin sometimes means very little. 

The Japanese generally have the best electronics, the Germans generally have the best metal and machinery, and the Chinese can be all over the board. 

Italy has also been all over the board. I learned that there are several Chinese companies which bought Italian companies and essentially have a Chinatown in Italy so they can retain the "made in Italy" status. One of the reasons COVID was rampant in Italy before elsewhere in Europe, Chinese travel. 

American made stuff can also be all over the board, especially in the Automotive sector. We have done much the same as Italy. Although my Honda is made in the USA, and my RAM is made in Mexico..... the Honda just burned an exhaust valve at 142,000 miles and the RAM just got a new radiator at 1 year old, Spanish made radiator. Replaced with Tiawan aftermarket. Which will likely last much longer...

ChrisJ

Solid_Fuel_Man said:

As I've worked on many cars from all over the world, and on much industrial machinery also from all over the world. I've come to discover that....as much as I hate to admit it.....country of origin sometimes means very little. 

The Japanese generally have the best electronics, the Germans generally have the best metal and machinery, and the Chinese can be all over the board. 

Italy has also been all over the board. I learned that there are several Chinese companies which bought Italian companies and essentially have a Chinatown in Italy so they can retain the "made in Italy" status. One of the reasons COVID was rampant in Italy before elsewhere in Europe, Chinese travel. 

American made stuff can also be all over the board, especially in the Automotive sector. We have done much the same as Italy. Although my Honda is made in the USA, and my RAM is made in Mexico..... the Honda just burned an exhaust valve at 142,000 miles and the RAM just got a new radiator at 1 year old, Spanish made radiator. Replaced with Tiawan aftermarket. Which will likely last much longer...

That's why I've brought up American made cars from the mid 70s-80s before.
I'm sorry but, that was nothing to be proud of.

Jamie Hall

Quite true, @Solid_Fuel_Man . What is also true is that you sort of get what you pay for. Sort of. But you have to balance the sizzle and gee whiz against the actual performance; if you want both, you are going to pay for it. Some of the best heavy equipment in the world is made in Sweden (Volvo). Not only do you get something which works and is going to keep working for the next few decades, but you get really first class service. On the other hand, a couple of the machines my son in law, who is a logger, uses cost more than a nice house... each. And new farm equipment -- a combine, say -- is right up in that price class too.

Solid_Fuel_Man

@Jamie Hall yes, it is unfortunate that Volvo automotive was bought by the Chinese and is focused on EVs only. 

The last Volvo car I had had well over 200,000 miles and drove like new. Japanese transaxle, Swedish 5 cylinder engine, and completly rust free even after 15 years in the Maine salt roads. Unheard of up here. Made in Belgium. 

DJD775

@Solid_Fuel_Man I didn't realize Volvo had such a big EV/hybrid portfolio. Once a company drops their manual transmissions they are dead to me. Eventually I might have to come crawling back

Jamie Hall

I wasn't thinking about Volvo cars! Though I have driven them and liked them. No, the two machines of which I was speaking are one, a gadget called a feller buncher -- a lovely critter which grips a tree up to 3 feet diameter, hangs on to it, cuts it, and tips it gently to the ground. The other is a contraption called a forwarder, which picks up 10 or so 2 to 3 foot diameter 16 foot sticks and wanders off through the woods to where they are picked up by a log truck...

I'm usually annoyed by the internet, but both of them transmit operating data back to Sweden, and the folks over there can usually spot things going wrong. Then -- or if something just quits -- they can get parts and sometimes even a mechanic if needed to you overnight (from Sweden!). That's service.

mattmia2

My grandparents always bought american cars and I think every car they bought from 1980 to the early 2000's got a new engine under warranty.

Solid_Fuel_Man

@Jamie Hall yes that Volvo heavy equipment is a site to see! My brother in law has his own forestry company band runs his personal forwarder. I think he has a TimberJack though. 

delcrossv

mattmia2 said:

My grandparents always bought american cars and I think every car they bought from 1980 to the early 2000's got a new engine under warranty.

Wow. My experience with American cars is somewhat different.
1999 truck 191,000 mi
2009 van 310,000 mi- in all fairness, this one is getting a little tired. but starts every day.
2005 suv 89,000 mi

All on the original engines.

mattmia2

delcrossv said:

mattmia2 said:

My grandparents always bought american cars and I think every car they bought from 1980 to the early 2000's got a new engine under warranty.

Wow. My experience with American cars is somewhat different.
1999 truck 191,000 mi
2009 van 310,000 mi- in all fairness, this one is getting a little tired. but starts every day.
2005 suv 89,000 mi

All on the original engines.

1980 98 diesel
~1987 Lincoln
early 90's dodge shadow
maybe the last lincoln or 2 in the early 2000's didn't self destruct

delcrossv

All mine are GM (Chevrolet). K2500 Suburban, 2500 Express van, Trailblazer.

ChrisJ

delcrossv said:

All mine are GM (Chevrolet). K2500 Suburban, 2500 Express van, Trailblazer.

That's why I said mid 70s -1980s.  Its been my experience that by the 1990s things started changing.

But your 99 I'm sure had some work done to it.  Specifically intake manifold gasket etc depending on the engine.

I've never owned a GM that didn't have cooling system issues it's entire life actually.  It's the main reason I gave up on them.  I got tired of adding coolant and changing water pumps, expansion tanks, stupid cheap plastic fittings.

Jamie Hall

We've never owned a GM, @ChrisJ , that did have cooling system problems -- including two Vegas. The first GM my family bought was a 1950 Buick, and we've had GMs ever since, together with a couple of VWs (Fill the oil and check the gasoline, please) and a couple of Hondas. Three of those had aluminium blocks -- the two Vegas and one of my Buicks. Loved them. And before you ask, the only care we had in there which used oil was one of the VWs; don't know why it did, but it would only go about 200 miles on a quart.

ChrisJ

Jamie Hall said:

We've never owned a GM, @ChrisJ , that did have cooling system problems -- including two Vegas. The first GM my family bought was a 1950 Buick, and we've had GMs ever since, together with a couple of VWs (Fill the oil and check the gasoline, please) and a couple of Hondas. Three of those had aluminium blocks -- the two Vegas and one of my Buicks. Loved them. And before you ask, the only care we had in there which used oil was one of the VWs; don't know why it did, but it would only go about 200 miles on a quart.

My 1987 Grand Prix didn't have any problems.
My 1992 C2500 did as it got older, but all of my newer stuff did from day 1. I'm talking 2006 and 2012.

EBEBRATT-Ed

With Fords it's always brakes, And no it's not my driving. I drove GMC & Chevy company pick ups and vans and went 80,000=100.000 before the brakes needed any work.

They are all junk now

I just traded in a 2015 Ford Edge.

It has a sealed differential with no way to add or change fluid. How stupid.

I have always bought American cars and trucks, except for my first car a 1965 VW Beetle. (I would have kept if except it was like being in a freezer all winter)

Except this time I traded for a Hyundai

But I still have my 2007 F150 with the anti theft device (5 speed)

ChrisJ

EBEBRATT-Ed said:

With Fords it's always brakes, And no it's not my driving. I drove GMC & Chevy company pick ups and vans and went 80,000=100.000 beforthe brakes needed any work.

They are all junk now

I just traded in a 2015 Ford Edge.

It has a sealed differential with no way to add or change fluid. How stupid.

I have always bought American cars and trucks, except for my first car a 1965 VW Beetle. (I would have kept if except it was like being in a freezer all winter)

Except this time I traded for a Hyundai

Me too, exactly,
So far I'm at 67K and all I've done is oil changes and filters.

DJD775

EBEBRATT-Ed said:

It has a sealed differential with no way to add or change fluid. How stupid.

I wonder how they got the fluid in there when it was built. Fill it before the axles are installed?

I always hate when car manufacturers state that some of the fluids/lubricants are "Lifetime". BS! I want my vehicle to last more than their definition of lifetime.
That being said even the worst cars today a very reliable.

ChrisJ

DJD775 said:

EBEBRATT-Ed said:

It has a sealed differential with no way to add or change fluid. How stupid.

I wonder how they got the fluid in there when it was built. Fill it before the axles are installed?

I always hate when car manufacturers state that some of the fluids/lubricants are "Lifetime". BS! I want my vehicle to last more than their definition of lifetime.
That being said even the worst cars today a very reliable.

Under normal conditions with a proper design manual transmission and differential oil essentially is "life time". It doesn't get diluted with fuel or full of carbon and moisture typically isn't an issue. So unless it's leaking, it should be fine.

Refrigerator and air conditioners etc all also have "life time lubricants". I don't exactly see anyone running around changing them.

JakeCK

EBEBRATT-Ed said:

But I still have my 2007 F150 with the anti theft device (5 speed)

Lol I miss driving a stick sometimes. 

I feel everyone should have to learn how to drive with one. It teaches discipline and how to read the road. 

DJD775

ChrisJ said:

DJD775 said:

EBEBRATT-Ed said:

It has a sealed differential with no way to add or change fluid. How stupid.

I wonder how they got the fluid in there when it was built. Fill it before the axles are installed?

I always hate when car manufacturers state that some of the fluids/lubricants are "Lifetime". BS! I want my vehicle to last more than their definition of lifetime.
That being said even the worst cars today a very reliable.

Under normal conditions with a proper design manual transmission and differential oil essentially is "life time". It doesn't get diluted with fuel or full of carbon and moisture typically isn't an issue. So unless it's leaking, it should be fine.

Refrigerator and air conditioners etc all also have "life time lubricants". I don't exactly see anyone running around changing them.

Maybe if you could you would have refrigerators that last more than 8-10 years