Why The Demise of Timing Belts?

Joined
Jun 3, 2002
Messages
8,324
Location
MI
For us old timers, there have been numerous automotive technology changes in the past decades that we have been slow to accept. Some are drive by wire, direct injection, $300 key and headlight replacement, just to name a few. I remember when timing belts were lauded as the next best technology. Now they have almost completely disappeared. Why??
 
Joined
Sep 18, 2012
Messages
6,040
Location
DFW
I'm not sorry to see them go, regardless of the underlying reasons. They basically guaranteed either expensive scheduled maintenance or several hours of labor working in very tight quarters. I'm sure others will chime in on the exact technical reasons, but I'm pleased with the trend.
 
Joined
Apr 9, 2008
Messages
15,194
Location
Central NY
It's an unacceptable third world cost cutting measure that serves no purpose other than to save the manufacturer $20 on the cost of a vehicle, yet cost the owners multiple thousands of dollars over the lifetime of the vehicle. I'm glad to see them go - they are completely unacceptable. There is no reason I should have to disassemble the entire front half of the engine so I can spend all day changing the glorified rubber band that drives the camshafts. It seems that people are realizing that they add significant cost to the vehicle ownership. It's a cheap way to make an overheat cam engine. Period.
 
Joined
Oct 1, 2010
Messages
8,085
Location
Michigan
Yes, mostly it's reduced maintenance. Too many people were ignoring timing belt change recommendations. Automakers sure aren't saving money using modern chain systems that have automatic tensioners and full perimeter guides. Chains also require less packaging length than belts.
 
Joined
Aug 5, 2011
Messages
778
Location
Southeast Michigan
There were also promised NVH improvements from timing belts that didn't end up being worth the tradeoff in M&R costs... especially when engineers started looking for other ways to cancel or abate noise.
 
Joined
Nov 4, 2013
Messages
9
Location
Chicago
I would guess that another factor is those "total cost of ownership" calculators at websites like Edmund's and such. It's much easier for somebody to do their research on scheduled maintenance these days. Seeing that there's a $900 service at 100,000 miles isn't going to win that car any points with a buyer.
 
Joined
Feb 15, 2003
Messages
11,281
Location
Jupiter, Florida
I'm still waiting for the return of pushrods..... (just kidding) I hate timing belts and the associated problems. I'd much rather have a well engineered timing chain system. My 4.6L F150 is at 300,000 miles on the original chains (M1, 10W-30 every 5K) and still operates perfectly.
 
Joined
Apr 9, 2008
Messages
15,194
Location
Central NY
Originally Posted By: BrewCity
I would guess that another factor is those "total cost of ownership" calculators at websites like Edmund's and such. It's much easier for somebody to do their research on scheduled maintenance these days. Seeing that there's a $900 service at 100,000 miles isn't going to win that car any points with a buyer.
It's even worse than that! The first generation Aveos had a timing belt service interval of 60K miles. But the belts and pulleys wouldn't make it past 30K before breaking.
 
Joined
Oct 3, 2014
Messages
1,892
Location
NoVA
Yep the "total cost..." is why manufactures pushed there trans to "lifetime" fluid, oil change to long on cars that sledged, etc... so it made their cars look more easy to maintain and cheaper in the long run. Timing belts were one of those things like a HOA. If it (house/car) has it you will scare off a fair amount of people. I'm glad they are dying if not almost dead. Did a timing belt on a Honda last weekend and after 100k from a salt state it was harder than it should have been. That and the customers bill was larger. If not for the timing belt I would not have had to charge them for the timing belt service, water pump, and valve cover gasket.
 
Joined
Nov 9, 2008
Messages
18,713
Location
NH
Makes me sad. No I would not look forward to doing the belt job on my DOHC V8 in my truck. Tight packaging indeed. But as I tick past 300k on my Jetta I wonder how many chains would still be in good shape at such high miles. IMO wear items ought to be easily replaced; or at least reasonably so. A few hours of labor every 100k is hardly bank breaking. How many wear parts are in the typical timing chain? I've seen it surmised that the chain on a bicycle is its most complex part; its certainly the most wear-prone part. [Very rough life it lives.] Bicycle chain has more than 100 moving parts--how many wear points in the typical auto timing chain, between rollers, pins and tensioners and guides? I've seen the belt get replaced on my car. 5 hours moving at a moderate pace. Special tools required? Sure, but call me when special tools aren't required to mount&dismount tires. I think it's a step backwards. But I'm not the typical buyer I guess. I'm tired of buying new cars only to replace every 10yr/200k and realizing that it's money down the drain.
 
Joined
Apr 9, 2008
Messages
15,194
Location
Central NY
I'm not sure I follow your logic. Having a timing belt makes an engine last forever, where a chain doesn't? There's a lot of chains out there with 300K miles on them. Generally, they don't fail catastrophically. A timing belt generally just snaps when its time is up.
 
Joined
Aug 3, 2003
Messages
1,420
Location
Balto.
Originally Posted By: Miller88
It's an unacceptable third world cost cutting measure that serves no purpose other than to save the manufacturer $20 on the cost of a vehicle, yet cost the owners multiple thousands of dollars over the lifetime of the vehicle. I'm glad to see them go - they are completely unacceptable. There is no reason I should have to disassemble the entire front half of the engine so I can spend all day changing the glorified rubber band that drives the camshafts. It seems that people are realizing that they add significant cost to the vehicle ownership. It's a cheap way to make an overheat cam engine. Period.
That pretty much sums it up. I avoid timing belts when buying and so do many customers. The manufacturers are listing. Cheers2
 
Joined
Jun 28, 2012
Messages
2,998
Location
Southern Illinois
+1 "It's a cheap way to make an overheat cam engine. Period" And most timing chains now have a spring loaded tensioner for the slack that occurs.
 
Joined
Nov 9, 2008
Messages
18,713
Location
NH
Originally Posted By: Miller88
I'm not sure I follow your logic. Having a timing belt makes an engine last forever, where a chain doesn't? There's a lot of chains out there with 300K miles on them. Generally, they don't fail catastrophically. A timing belt generally just snaps when its time is up.
It doesn't make it last longer. It's just easier to replace. It's also a good time to replace the water pump & change a bit of coolant too. Long life / 5 year coolant, refreshed every 100kmiles. And, there becomes nothing magical about 300k. 300k, 400k, 500k. The belt & parts are getting refreshed. Motor just marches on. Won't get junked when the chain tensioner runs out of adjustment. I dunno. I'm used to reading about how VW screwed up their chains. Passats and their balance shaft, VR6's with the chain on the back of the motor. Toyota's legendary 22RE liked to eat a chain every 200k. Nissan's I4 in their trucks apparently were no different. GM's pushrod motors had long lived timing chains (once past nylon gears) but they were also about six inches long. Exploders had something on their 4.0 IIRC.
 
Joined
Feb 8, 2013
Messages
1,797
Location
Texas
For the same reason Trav and millerbl00 aren't interested in direct injection. It's extra stuff you have to do to keep your car on the road. Personally, one of my least favorite jobs has been timing belt work, and I'm very happy that I don't have to do it anymore.
 
Joined
Oct 8, 2006
Messages
10,372
Location
OH
Why belts or chains? Why not something that truly would never wear out like gears?
 
Joined
Jan 3, 2006
Messages
1,587
Location
Ohio
I'm kind of torn. I was not looking forward to a timing belt replacement on the ex-wife's Subaru. Even if it was supposedly good for 100,000, the procedures looked like I might want to let the pros do it. I was glad not to have them on my later generation CR-V's (first gen had them). A buddy of mine had a old Elantra that broke its belt long before it was due and mangled a few valves while leaving him stranded. Then I hear about timing chain problems some of the 3.6 engines have had, and think maybe a belt isn't so bad. I watched a time-lapse video of a timing chain replacement on a Lambda vehicle, and it's a major job. Lifting it up, dropping the engine/transmission, 3 separate chains, idler gears, lots of guides and tensioners. Yikes.
 
Joined
Nov 9, 2008
Messages
18,713
Location
NH
Originally Posted By: grampi
Why belts or chains? Why not something that truly would never wear out like gears?
My understanding is that they can have higher noise, and higher requirements to set up properly. Not impossible (otherwise transmissions and rearends wouldn't work). But kinda hard on SOHC/DOHC setups, not without lots of gears. Each of which would be yet another wear surface.
 
Top