How many miles on your TIMING BELT when it failed? What happened? (1 Viewer)

[Brandon Ryder]

Outstanding evidence! You mentioned miles on the belt. How about age? Living in your part of California, do you think that heat and arid conditions play a role in degradation of the belt?

weather conditions not a factor here. rarely gets into the 80s. not exactly sure when it was changed by timeframe but belt had no signs of age cracking. only possible theory is tensioner went bad. im not really sure how to check that. otherwise just a bad belt. previous owner ran the timing belt (original) until it broke aground 190k. he had a local shop, not the dealer replace it. they used the gates belt and green coolant. not sure what else they changed.

it had 275k when i bought it. it's still under 280k right now.

 

[abuck99]

Many manufacturers recommend timing belt change intervals between 60k and 90k miles. Sure there are examples of 150-200k on Toyota original belt but its like playing roulette with all the component and environmental variables in involved. The Toyota belt is a trustworthy part but depending on who does the service work you or dealer or Indi- the parts used( or not replaced) in our TB job could be anything unless you specify exactly what you want part by part.

#1 Age & Miles. 7-10 years < 100k miles.

I believe that the way you drive and the environment you operate in has a measurable impact on TB belt life after the prescribed service interval. If you are consistently hard on the accelerator, tow a lot, armored lifted 34-35" tires there is added strain on the belt. Belts can stretch, the teeth can wear down and slip, oil, coolant or grit debris can get into the area and weaken the belt, tensioner can loosen causing belt to slip a tooth, pulley bearings do wear out, high heat dry environment and hot engine temps can prematurely age a belt; many variables involved..

There have been some recent belt failures posted on the forum; one posted above looks like a tensile break- could be poor materials, too much belt tension, a heavy foot, degradation from leaking coolant or all of the above. Pulley's even though they spin freely with inspection, when the belt is on and tension applied its completely different. Also a pulley with any play in the bearing will cause a little fractional wobble/vibration misalignment; and that impacts belt life.

When a belt "breaks" it's super important to get to the root cause because in theory it shouldn't happen with proper replacement intervals.

Some common belt failure causes:

• AGE/MILES
• Poor/improper installation
• Excessive load
• Under tensioned belt- weak/worn tensioner
• Weak drive structure: belt stretch & vibration
• Debris (coolant- oil- dirt/grime) in the crank or cam pulleys wearing teeth
• Failed component- seized idler/tensioner pulley or waterpump
• Misalignment- worn idler/tensioner pulleys

 

[ClassyJalopy]

I'll let you know after i replace my timing belt this weekend. wife was driving and the engine just shut off. she was going maybe 25mph. check engine light and battery light came on as she rolled to the side of the road. i tried to crank it when i got too her but it wouldn't start. has a p0340 code crack shaft position sensor.

those are the signs when it happens. belt broke basically in half. right around 90k since it was replaced. it's a gates belt. nothing else failed that caused the belt to break to my knowledge. water pump and idlers spin freely. previous owner also had a timing belt break on him when he changed it last. engine was fine. I'm hoping it's fine again. this is a 2000 lc by the way.View attachment 1927592

Use the AISIN kits this time. I wouldn't trust anything less for something as critical as the timing belt

 

[ClassyJalopy]

I am in the middle of timing belt job (day 3 today!). I had only 70 k miles and about 6 years on the belt. Last timing belt job was at a reputable Lexus dealership. Had my fan bracket not given up the ghost, I would have not have replaced the timing belt.

Now the best itself came out looking new (it is Toyota branded)! The waterpump looked new too and there were no leaks anywhere whatsoever!

 

[JT4runner]

I just replaced mine earlier in the week. I kept having a very rough idle and me and a buddy thought it was just an ignition coil but was lots worse. After doing more research found out my timing belt was shredded. The PO had the timing belt changed in Nov 2017 and less than 50k miles. I believe one of the cam seals was bad and oil somehow leaked on the timing belt and make it skip a few teeth. I went with the Aisin kit and also OEM cam and crank seals, thermostat and also OEM coolant. She runs great now.

 

[gatormark91]

Changing the timing belt = changing the water pump. I'd say my 250K+ LC still had the original pump in it, although the belt had been changed. The impeller looked like crap and was beginning to get a tad crunchy. Water pump failure is going to break your timing belt, which is going to leave you by the side of the road. Not so much a big deal here, but maybe deadly in some of the remote areas that Land Cruisers are expected to be used. I changed mine because I don't want to be stuck on the trail somewhere.

 

[JT4runner]

If you purchase the Aisin TKT-021 it comes with new timing belt, water pump, idler bearing, tensioner bearing and I believe something else. Best buy for the money.

 

[abuck99]

Buy the AISIn TKT-021 from a reputable seller- there are a lot oc counterfiet parts on Amazon and Ebay

 

[Riviera]

Changing timing belts at 90k intervals is yet another method The OCD crowd uses to skew the mythical high cost of owning a Land Cruiser.

Who the heck thinks changing your timing belt (and water pump, etc) is OCD? I'm baffled by this. But then again, I don't want to break down from something that is mostly preventable. I've worked in automotive and equipment for over 20 years, and I'll just keep taking care of my stuff.

 

[BullElk]

Who the heck thinks changing your timing belt (and water pump, etc) is OCD?

"...at 90k intervals".... Is what I said. IMO, that is OCD because the belt and all the components will predictably and safely last much longer.

You've been in the business for over 20 years. Since you brought that up, tell us how many people you know have had their Land Cruiser break down from not doing their timing belt service at 90k mile intervals. How many people do you know in the last 20 years of professional experience that have broken down due to the Land Cruiser 4.7 timing belt or water pump?

 

[Riviera]

I don't work at a Toyota dealer. I don't think running it until it breaks is the smarter option, and furthermore I am positive that most customers find that breaking down is an inconvenience and something best avoided. I like the piece of mind when I drive in bad weather, remote areas, and through bad neighborhoods that I've done my part to lessen the chance I breakdown, especially with passengers. I sure as hell wouldn't go wheeling with anyone who didn't have the common sense to do recommended maintenance.

 

[JT4runner]

Buy the AISIn TKT-021 from a reputable seller- there are a lot oc counterfiet parts on Amazon and Ebay

How can you tell if it is counterfeit or not?

 

[BullElk]

The inconvenience of breaking down is exactly why my family of six have driven 10 LC/LXs the last 23 years. I have had one water pump bearing to go bad. And it had only 30k miles on it installed by previous owner....fluke. However, I do believe that piece of mind has a legitimate value.

 

[Riviera]

The inconvenience of breaking down is exactly why my family of six have driven 10 LC/LXs the last 23 years. I have had one water pump bearing to go bad. And it had only 30k miles on it installed by previous owner....fluke. However, I do believe that piece of mind has a legitimate value.

Obviously you've had several Toyotas, and you know your vehicles well. I also believe your vehicles are reliable. I, on the other hand, have bad luck, and if I break down, it will be at 1 in the morning, in a snowstorm, with my wife in the car, and I'll never hear the end of it!! LOL. I shouldn't say what is common sensor, or not common sense, it should be what works for you. We all drive Toyota/Lexus because we think they are very reliable ..................... and great on gas! LOL.

 

[Brandon Ryder]

"...at 90k intervals".... Is what I said. How many people do you know in the last 20 years of professional experience that have broken down due to the Land Cruiser 4.7 timing belt or water pump?

me!

 

[gatormark91]

Obviously you've had several Toyotas, and you know your vehicles well. I also believe your vehicles are reliable. I, on the other hand, have bad luck, and if I break down, it will be at 1 in the morning, in a snowstorm, with my wife in the car, and I'll never hear the end of it!! LOL. I shouldn't say what is common sensor, or not common sense, it should be what works for you. We all drive Toyota/Lexus because we think they are very reliable ..................... and great on gas! LOL.

I changed my belt when I bought my truck because it came with no records, just the word of the third owner who said he had the timing belt changed. Which was actually done, looking at the belt, but the shifty mechanic that did it for him did JUST the belt, and put on a cheap Gates belt. WP, tensioner, pulleys - all original.

I changed it because now I KNOW it's done right, because I did it myself. I don't expect to change it at 90k miles, because I don't drive it that much. Even if I did, I'm not going to pull over and park it if I go a mile over 90K. maybe 120K or close... But it's an extra fun vehicle, so the belt will age out before it runs out of miles.

But most of the recommendations aren't "OMG, your truck is going to die if you don't do it every 90K", the recommendation is "You just bought your truck, unless you see the AISIN belt change sticker or have a receipt, do it"... because I trust people just about as far as I could throw them. If you don't know, it should be done. If you do know it's good, no one is saying that death and disaster are going to happen if you go 91K miles without a belt change.

 

[BullElk]

me!

There’s one. Do we have two?

There is a light years better chance of breaking something wheeling or crawling than breaking down due to a TB failure.

 

[Asanka]

Again, only respond if you had complete breakdown of the timing belt, not how long you got out of your belt before you decided to change it.

Not mine broke but saw someone parting out an early 100 with toasted engine due to timing belt failure. That had 400k plus miles on original belt.

 

[dirtEJohnson]

Good point. Having done "a couple hundred t-belt jobs" shows your experience. Would you share with us any PM tips other than scheduled PM that we can do to ensure optimal mechanical performance on the timing belt mechanicals?

That's not really the intent of the OP and I'm certainly no guru. As a turn of the century line tech in an import store, that's just what we did. T-belts were the norm and I've seen a boat load broken for multiple reasons. Belts that "look fine" with sheared teeth or clean breaks. Plenty of parts with a limited life expectancy sharing a small space.

Have I ever seen a Cruiser with a broken belt? No. Other 4.7's, yes, but with north of 200k. I haven't even been into my own as of yet as it came with service records, but my gen 1 Tundra 4.7 belt looked good as new @170k.

My point is more often than not it's something related that takes the belt out. A good example is the tendency of Toyota pink coolant creating crusty little pink mineral deposits that can get ground up into an effective abrasive when it weeps over time from the pump. Not uncommon on other Toyota models.
The OP wants to know why and how. I'm saying there are many ways and I believe in changing it all at the appropriate interval.

 

[Brandon Ryder]

There’s one. Do we have two?

There is a light years better chance of breaking something wheeling or crawling than breaking down due to a TB failure.

oddly enough... the previous owner of my cruiser. does that count as two?