Timing Chain vs. Timing Belt

[clinebarger]

Originally Posted by Eddie
I preferred T belt when I could do the work to change the belt but, when I got too old to do belts, I prefer a chain. You ask why? Because dealers seem to love high dollar maintenance jobs. Ed


I agree with that for the most part....Plenty of your "average at best" Honda/Acura & Toyota/Lexus technicians got blindsided when the gravy-train customer pay maintenance jobs dried up.

More than a few tried the jump to Cadillac & found they have to work for a living, We had plenty of customer pay jobs....But getting paid 5 hours for 2 hours of work was harder to come by than they were accustom to.

 

[Cdn17Sport6MT]

Originally Posted by exranger06

Belts USUALLY only fail when the owner neglects to change it at the manufacturer recommended interval. A typical interval is every 90k miles or every 7 years, whichever comes first. The problem is, many non-car-savvy people don't even know what a timing belt is or that you're supposed to change it every so often. So they have a belt that's 10+ years old and has 150k+ miles on it, and one day, it snaps without any warning. You're supposed to change them LONG before that happens, while the engine is still running fine. And yes, interference engines with timing belts are VERY common. Many engines have suffered valve damage from people who didn't change their belts on time. As long as you change the belt AND replace the other wear items driven by the belt (tensioner and idler pulleys, water pump) according to the recommended interval, you shouldn't have anything to worry about.


LOL... my first car was a 1972 Fiat 124 Sport Coupe... the first production car to use a belt (in this case, for its DOHC arrangement). Changeout interval was 40,000 km / 25,000 miles! It was an interference engine. I never did have to find out the hard way why that interval was so short (meaing, I DID change it on time). So when I hear of 90,000 mile intervals... well, I think that is just fine.

Had an '87 Reliant 2.5 I4 engine... Non interference. I let the belt break. Wife to this day never will forgive me. Towed it home, replaced, ran and ran and ran after that.

Have a '99 Toyota Camry, I4... Non Interference. I bought car used - and no info on whether it was ever changed. I suppose I ought to do it (and change water pump at same time... with an Aisin wtr pump). NOT looking forward to having to change out cam-seal... as apparently it requires three men and a boy to get the nut off the end of the camshaft. Also, have to creatively pry out seal without damaging the bore it sits in, or the camshaft sealing surface. Use a metal screw into the seal rubber, plus a cat's paw. Also, not looking fwd to having to get nut off crankshaft drive pulley / harmonic balancer.... Ugh!

I have a '97 Civic EX 1.6. Belt has timed out (not miled out)... and it's on only its second belt. Time-bomb. Apparently a PITA to change out. Funny having transverse engine opposite orientation vs almost all others. Apparently 'real tight to access.
Another ugh :| .

 

[supton]

Originally Posted by DGXR
Timing chains are designed to last the life of the engine. People talking about changing timing chains... that is only necessary in very high mileage engines,

What's high mileage? Since all cars go 200k today, I'm thinking high miles is someplace past 300k.

Quote

An interference engine with a timing belt is just a disaster waiting to happen, not sure if this combo was ever produced but I sure hope not.

They certainly exist. I believe many Honda's are, Toyota's legendary 4.7 become one when they added VVT, VW TDi's are, the list goes on and on.

I dare say, it's best to assume a TB motor is interference, until shown otherwise. The simple fact that it will brick the car when it breaks (damage or otherwise) is reason enough to change on schedule (unless if your idea of fun is being stranded with no warning).

 

[supton]

Originally Posted by Cdn17Sport6MT
Have a '99 Toyota Camry, I4... Non Interference. I bought car used - and no info on whether it was ever changed. I suppose I ought to do it (and change water pump at same time... with an Aisin wtr pump). NOT looking forward to having to change out cam-seal... as apparently it requires three men and a boy to get the nut off the end of the camshaft. Also, have to creatively pry out seal without damaging the bore it sits in, or the camshaft sealing surface. Use a metal screw into the seal rubber, plus a cat's paw. Also, not looking fwd to having to get nut off crankshaft drive pulley / harmonic balancer.... Ugh!


Been a couple years now but I didn't find it that bad. I did get a cheapo compressor and a HF Earthquake impact at some point in time, and it's nice to have for jobs like this. Just use an impact rated socket (it isn't a Honda where a special impact socket is required).

IIRC you pull the passenger wheel, then pop off two 10mm bolts to remove a splash cover. Then you have full view of the harmonic balancer. Push come to shove, pay a local shop to zip the bolt off, then snug it back in by hand for you.

I think the harmonic balancer gave me the most grief, as I had to scrounge around for the right bolts to work with whatever cheapo puller I had--again, I forget now, but I recall it being problematic. The worst was access to getting the alternator bracket off, just too little space; and Toyota was stupid on the drive belts--the alternator has a proper tensioner setup, yet you have to use a prybar to set the tension on the power steering pump, go figure.

I skipped doing the crank and cam seals. I suspect when I do it next time I'll just screw in drywall screws if I have problems getting them out with typical pry tools.

FWIW there is a nice kit out there with everything you need, and then some. Water pump etc. I'd have to look up the p/n for it, but all quality parts, for like $180 or $200. I decided to pay the extra money and go with Toyota red coolant, it's not that expensive.

It may be worthwhile to just shotgun the valve cover and spark plug tubes while at it, as they harden up and leak. Right now i'm putting off doing the oil pan gasket as that is leaking on me. Oh, and plan on doing the oil pump seal, as the o-ring gives out, and it's behind all the timing belt stuff--do it once, do it right. It's no real extra time to do it, once you have the belt off.

 

[WyrTwister]

Originally Posted by Trav
Originally Posted by vwmaniaman
I prefer neither belt or chain. I like the old fashioned gear on gear drive bathed in oil. They never fail for the life of the motor. My old VW's are my example.


That is the best but a bit tricky with modern higher output DOHC V engines, it has been done though. Duesenberg DOHC with gears, it looks like the top 3 could be eliminated on a modern engine but the physical size of the block may pose issues.

Edit: The sound from that drive must be amazing.


Looks like an absolute nightmare . How many heads on that engine ? Three ?

 

[pezzy669]

While I would prefer a "maintenance free" chain I am impartial to either chain or belt. My new to me TDI is a belt with a 120k change interval, it will time out at 10 years before I hit the mileage though.

On the other hand I would take a belt any day over a vehicle with known problematic chain systems. My '06 Jetta 2.5 already had chain rattle and slap with only 60k on the clock despite on time oil changes with the proper VW 502 5W-40. Then there are the pre-'09 Mercedes M272 with balance shaft gears made of play-doh, the GM 3.6, heard the newer VW 1.8 and 2.0T have pretty bad chain systems.

On the other hand my sister had ~255k miles on her 2010 Civic with the R18 last Summer, she is probably at 275k now and the engine has never been opened up. If this was an older Civic with timing belt I think she would be on her 2nd or 3rd belt by now.

 

[Kjmack]

Originally Posted by pezzy669
While I would prefer a "maintenance free" chain I am impartial to either chain or belt. My new to me TDI is a belt with a 120k change interval, it will time out at 10 years before I hit the mileage though.

On the other hand I would take a belt any day over a vehicle with known problematic chain systems. My '06 Jetta 2.5 already had chain rattle and slap with only 60k on the clock despite on time oil changes with the proper VW 502 5W-40. Then there are the pre-'09 Mercedes M272 with balance shaft gears made of play-doh, the GM 3.6, heard the newer VW 1.8 and 2.0T have pretty bad chain systems.

On the other hand my sister had ~255k miles on her 2010 Civic with the R18 last Summer, she is probably at 275k now and the engine has never been opened up. If this was an older Civic with timing belt I think she would be on her 2nd or 3rd belt by now.

VW's after 2012 have better chain tensioners

 

[Trav]

Originally Posted by WyrTwister
Originally Posted by Trav
Originally Posted by vwmaniaman
I prefer neither belt or chain. I like the old fashioned gear on gear drive bathed in oil. They never fail for the life of the motor. My old VW's are my example.


That is the best but a bit tricky with modern higher output DOHC V engines, it has been done though. Duesenberg DOHC with gears, it looks like the top 3 could be eliminated on a modern engine but the physical size of the block may pose issues.

Edit: The sound from that drive must be amazing.


Looks like an absolute nightmare . How many heads on that engine ? Three ?


No only two, 12 cyl on each side. 24 cyl DOHC with mechanical fuel injection from wait for it.... 1925!

 

[nobb]

Having a timing belt makes for a good excuse to change out a bunch of the auxiliary components like water pump, drive belts, and etc during service. Even though timing chains are made to last the life of the engine, often times the water pump does not so it makes for piece of mind to change that out.

 

[ekpolk]

Originally Posted by Trav
. . .

No only two, 12 cyl on each side. 24 cyl DOHC with mechanical fuel injection from wait for it.... 1925!





Wow! I wonder how many cylinder's worth of its output was dedicated just to overcoming its own internal friction? I'm guessing that fuel economy was NOT this engine's strong suit.

Still, it must have sounded pretty nice! Thanks for posting that Trav.

 

[ofelas]

My vote is for timing gears + a single-bearing for an in-block cam + mechanical injection

 

[ofelas]

Yes 3 heads, not two. Three banks of straight 8s (six 4 bangers in total) with a common crank on that old boat motor. 96 valves to set lash on ;-)

Originally Posted by Trav
Originally Posted by WyrTwister
Originally Posted by Trav


That is the best but a bit tricky with modern higher output DOHC V engines, it has been done though. Duesenberg DOHC with gears, it looks like the top 3 could be eliminated on a modern engine but the physical size of the block may pose issues.

Edit: The sound from that drive must be amazing.


Looks like an absolute nightmare . How many heads on that engine ? Three ?


No only two, 12 cyl on each side. 24 cyl DOHC with mechanical fuel injection from wait for it.... 1925!

 

[Trav]

I found a site looking it up that says it is a W engine not a V engine like the first one I saw which said it said V24. I know nothing about the engine. Can you imagine the maintenance on it, holy cow.

 

[supton]

Yeah but I imagine if you could afford to buy it, you could afford to maintain it. That was 1925, right? No 7 year auto loans back then.

Impressive bit of technology though.

 

[Trav]

Back in those days American cars were equal to anything on the the planet and even better in many cases. Duesenberg, Auburn, Cord, Packard, Cadillac, and others were among the best of the best. US manufacturers can do it anytime they want, I have no idea what the motivator has to be go get them in gear though. The new Vette may well be a game changer.

 

[Wagonmaster261]

My preference: Gears, then belts for non-interference OHC, then chains.

I have each in my fleet: 300 with gears, 2.0 Zetec with a belt, and 2 3.8 V6 with chains. Used to have 2 3.0 Duratecs with chain drive DOHC, didn't have any issues with over 200k miles.

Belts can keep some of the harmonic situations away from the cam and timing. Must be something to it if they are used on racing engines.

Belts and chains are both maintenance items with a service life. Belts are usually easier to change, with less tensioner issues and so forth on a OHC engine.