Timing chain

Maintenance/Repairs
21

“IMHO it’s a very expensive procedure for the average worker to have to do on a scheduled basis. $600 or more is not an unusual bill for this process. That’s a lot of money for routine maintenance.”

$600-$800 for a maintenance item that will be done once, maybe twice, in the life of the car, assuming 100,000 mile service intervals. $800 every 100,000 miles isn’t really that much money.

True, many chains will last over 200,000 miles or more, but many won’t. And then you’re looking at a potentially $2500 repair. The last car I had in here with a failed chain (because of a failed tensioner) had 130,000 miles on it. The cost to repair that was about what 2 timing belt jobs would have been on a similar car. In the end it’s all a wash.

“I too am inclined to suspect that the return to timing chains might have been due to customer dissatisfaction.”

I’m inclined to think that the return to chains is due to it being possible now where it wasn’t 25+ years ago. Timing belts were originally designed to run overhead cams where it was impractical for a chain to do so. Metallurgy, composite materials, and lubrication have advanced to where you can now have chains running through engines where previously it was better to have a rubber belt.

22

The cost of most timing belt replacements seems high because so many other parts are replaced incidental to the belt being accessed. Water pumps, accessory belts, cam and crank seals, etc., which would likely fail in the near future are replaced with the timing belt. If you skip all those incidental pieces and wait to replace them when they fail the cost would be outrageous not to mention the timing belt would be replaced when oil or coolant leaks on it. But then when timing chains are replaced on old Fords and Chevrolets it was SOP to also replace the water pump, drive belts, coolant, engine oil and filter.

23

Around here most cars with belts will need changing twice, with a timing chain never. If you drive 12000 miles a year, your car will die from rust at about 150,000 miles.

24

In my neck of the woods . . . southern California . . . cars do not die from rust. I’m talking about cars that spend their entire lives here

So timing chains may certainly be an issue

25

We just about never get questions from folds with worn timing chains here.

26

That’s probably because most of the engines still out there still have timing belts?

Out of all the vehicles that come into my shop? I’d say 20% have timing chains.

Tester

27

When was it ever impractical or insufficient to use a chain to drive Anything? I think we had the know how and Sufficient Metallurgy back in the 30’s to accomplish this. I found out in a Jaw Dropping moment that the only reason we had T-Belts Foisted upon us was for only One reason…COST. My heart almost broke on that day. I forget where I heard this but it was from “The Horses Mouth” of some sort…why I don’t recall who said it I think was because I was so mad that day… I do recall it was a prominent and knowledgeable member of a major mfg as well… I’m sorry I forget who it was…but I recall he was from Ford.

I don’t believe there was ever a mechanical issue that led to the belt… The routing of the belt is a soft route…no serious bends and distances are fine for a chain to handle it. One rumor was it happened for noise suppression…But I found out that was just a feature and not a motivating cause.

ASE…why do you say we had to use belts over a chain at any point in the engines evolution with overhead cams etc… What couldn’t the chain do? That doesn’t seem right to me…I think a chain could have easily been implemented…just as it is now. There wasn’t any Metallurgic wizardry that came along recently to make the chain possible for today’s engines…not that I’m aware of anyway. I mean its possible…I don’t follow this stuff religiously so… WAS THERE? Well no matter… I was just curious as to why you were saying that. Seems to me that we could’ve used chains of the stronger “Silent Chain Type” with all those layers of steel at any moment we wanted to without any issues

Blackbird.

28
Given how few vehicles make it past 250k, very few timing chains wear out.

Maybe they should start buying more reliable vehicles. Every vehicle I’ve owned with the exception of our current vehicles…I had no problem getting past 250k miles. A couple almost double that.

29

I think it also has to do with careful maintenance combined with lifetime ownership. Few cars are owned by a single owner who does excellent maintenance like you, Mike. 10-12 years, 150k or so is my limit.

30

All I do is follow the maintenance schedule outlined in the manual? Nothing more…nothing less. You telling me you don’t follow the manufacturers maintenance schedule?

31

Anyone working on all the popular models driven by the public would eventually run accross failed belts, chains and gears. I know I have seen several of each. But I replaced a great many belts as preventive maintenance and I never replaced a chain unless there was some indication of a problem. Any engine on the road today will eventually develope a statistically significant repair issue and those who find the issue as they read the repair estimate will likely be unhappy. Late model Ford V-8s are popular and somewhat trouble free but they occasionally have problems with the timing chain and anyone who has replaced one of those and also replaced the timing belt on a Mazda 929 will certainly prefer the Mazda.

32

?? Mike - just saying I don’t keep cars as long as you. That’s all. Cars that get traded 2, 3, or more times probably get poorer maintenance later in life, leading to their demise.

33

40 years ago it seems that carmakers couldn’t even make a conventional cam-in-block timing chain that would reliably last longer than 120-150,000 miles. My dad used to drive a lot for work and kept cars over the 200K mark, and some of those cars had to have the timing chain replaced twice. Of course they also had valve jobs, carb overhauls, etc in that time frame. As a young guy getting started I remember learning to use a timing light to check for a worn chain. And it was rare to find an engine with over 100K that didn’t have a sloppy chain. As an added bonus, some of those old timing chain engines were valve benders too.

Think about the difference in the metal, the plastics, and most importantly the motor oils from that time and now. Materials quality has advanced by leaps and bounds since the 70’s. Think how long a chain on a Chevy 350 is and how long the chains on a DOHC Lincoln V8 are. You’re talking quite a bit of difference. I really doubt the motor oil and plastics of 1972 would give that Lincoln chain set a longer life than a timing belt.

The Toyota 20R and 22R engines were OHC and used timing chains, and look how many broken guides and failed tensioners were replaced on those. I’ve replaced worn chains on late model Toyotas, GM Ecotecs, Honda 2.4s, Nissans, Chryslers, and many others.

34

I would also imagine a return to chains has something to do with public perception of the car make and whether the car owner will be a repeat buyer.

It doesn’t matter if the owner never reads the owners manual, is informed of a timing belt interval on their dime and which is quickly forgotten, or any other applicable reason.

When an ignored belt snaps and leads to the car owner being just stranded or stranded with major engine damage, most of them are going to take a dim view of the situation and will likely swear they will never buy a POS like that again.

35

ASE, I have great respect for you and your expertise. Understand please that the following comments and replies are motivated by a difference in belief, probably driven by a different experience base, and are in no way any reflection on my respect for you as a technician. You are one of the regulars here that I learn from. On this subject, I simply disagree. No disrespect meant.

I believe the technology to produce chains (including the associated hardware) that would last indefinitely has existed for longer than I’ve been alive. Chains have been in use since well before the automobile. They were commonly used on motorcycles and bicycles in the 1800s. The first known chain design was by Leonardo Da Vinci. The use of single row chains in engines with nylon sprockets and tensioners was simply cost cutting. Manufacturing technologies, metallurgy, and lubricants have certainly advanced these past 40 years, but the basic link chain is the same design, only manufactured with more efficient processes and lower cost.

I do believe that Lincoln engine’s cam drive system (poetic license) would have lasted indefinitely with a properly sized chain and sprockets… even with a nylon tensioner. Nylon (actually a family of polymers) has been around since the '40s. It was in common use for sprockets, gears, etc. by the '70s.

Truth is that if cost were no object engines would use geartrains with nice, quiet hypoid gears. But chains are cheaper and belts even cheaper still. There used to be geartrains available for racing, I assume there still are.

For the record, my 22R was the one that needed a new chain at 200,000 miles. None other of my engines ever have, including the one I’m currently driving with 224,000 miles.

Regarding the relative costs, if I add up all the vehicles I’ve owned over the years and add up the thousands I would have spent on timing belts that I didn’t have to spend because most of my engines used chains, belts would have definitely more expensive by a longshot. Not even close.

And there’s another major factor: anxiety. Taking a car in to have a belt changed is a highly anxiety provoking act. That adds greatly to the customer dissatisfaction that I believe may have provoked the return to chains.

36

I think it has to do with how many miles you drive a year. Because we have affordable, abundant housing stock all over the city and close suburbs here our commutes tend to be very short.

Over the years I worked for 32 trucking companies. The furthest I ever drove for work was 15 miles and I only drove that twice a week. My average commute was less than 5 miles.

Even with running 4 kids around we seldom put more than 10,000 miles a year on a car.

I used to drive about 125000 miles a year on company trucks but I never owned one.

Since there are many cars available now with timing chains, I see no reason to buy one with a belt.

Belts fail without warning, timing chains sing a long goodbye.

37

TSM, How dare you disagree with me?? Don’t you know who I am? Excuse me while I go kiss my hands and admire myself in the mirror…ha!

Today, I believe that a chain will generally last longer than a belt, but that’s not to say they’re trouble free. I see chains, tensioners, guides fail at less than 100K miles on well-maintained cars. They’re all moving parts, they’re going to wear, and some will fail. In the long run, it makes no difference to me whether a car has a belt or a chain. Nothing is trouble free. And given that timing belt service intervals are now 100-120K miles, I can’t see the cost as a significant factor when amortized over the life of a car. A set of struts, a clutch replacement, these will wear out and need to be replaced, often before a timing belt, and will cost more.

The technology to make lasting OHC chains surely has been around for a while, but think back to the 70’s when we were talking Vegas and Pintos. What kind of motor oil was around back then? A cheap and simple to replace belt to run the cam, or a chain with guides, tensioners, etc. that has to be enclosed in the engine and bathed with oil? Which one made more sense?

I’m guessing most cars out there will get the timing belt replaced once, with a very few twice. I think cars that go over 250,000 miles are such a small segment as to not be statistically significant. I can barely drive the same car for 3 years without getting bored with it. How can you guys go 200K+ and still want more?

I was right, I thought Mayweather would win the bout on points (for you boxing fans).

38

Just different philosophies. I take pride in having a 10 year old car that looks and runs as good as new. The older it gets, the more I enjoy it… assuming, of course, that I chose well in the first place. I did have to trade one in after only two months once because I made a bad choice. My dad enjoyed his cars, but in the end he considered them just conveyances.

I still think chains are by far the better choice for longevity, cost long-term, and anxiety free ownership. But if I got a new car every three years it might not matter to me. Perhaps it’s that difference that causes our diametrically different perspectives on this issue.

39

Granted, belts and chains both fail. However, I think that if you took say 1000 cars with a timing belt and 1000 cars with timing chains and ran them until they died odds are more of the belt driven ones would surrender first.
There’s a lot of complaints on this forum alone about failed timing belts but few involving chains.
I would strongly suspect that most chain and tensioner issues are caused by the same thing that leads to excessive oil consumption, oil sludging or coking, etc; insufficient oil change regimen.

Don’t take this to mean I’m anti-belt because I’m not and have no problem with them. I do agree that in many cases a chain replacement if needed can cost more (or far more) than a comparable belt.

I like driving the same car along with wearing the same jeans, using the same wallet (20 years and counting…) and living in the same house.
The only car I’ve ever gotten bored with was my old '87 Sable station wagon after 15 years and 400k+ miles and mainly because it was an uncool car. I like 2 doors, sleek, and go fast…

40

I’m a mechanic, I can’t afford to buy a new car every 3 years. I buy a different used car every few years, then trade when I’m tired of it or see something else I like.

My wife on the other hand, drives a 13 year old car and just wants to know how long I can keep it running. Forever, assuming the DOHC chains don’t go bad. :slight_smile: I’ve been trying to get her to buy a new car but she just won’t listen. Apparently she’s able to make up her own mind about things without me. One of the reasons I love her.