Timing Belt Failures On Tundras?

[Wallowa]

Tried to search for this but came up empty...my 4.7L '05 Tundra has what is termed an "interference motor"; if the timing belt fails with the motor running it pretty much ruin and self-digest the engine.

My question: Toyota recommends replacing the rubber/fabric timing belt at 100K miles or 10 years.

Has anyone actually had a belt break and ruin their motor?

My '05 was bought new and has only 41K; replacing the belt [water pump replaced as part of the repair] costs about $950.

I don't wish to be penny wise and pound foolish but neither to I want to either worry about this when in BFE or get hustled into replacing a belt that may go for another 100K. Carrying a '16 Hawk.

Any experiences and insights will be appreciated.


Thanks,

Phil

 

[DavidGraves]

Hi Phil

There is a pretty responsive group of folks at the web forum "Toyota nation"

I have been able to learn a lot duing the years owning our T100 and Tacoma.

They seem to have sub groups dedicated to different models.

Might look over yonder.

David Graves

 

[Beach]

Replace at 100k due to wear, replace at 10yrs due to cracking and the belt breaking down. I have coffee every morning with my bud that owns an auto shop and I have seen some belts replaced that were shot and on borrowed time, others that looked as if they could go another couple years. You won't know until you open up that motor to examine the belt and if you've gone that far, you might as well install the new part(s). The penalty for not doing it is much more expensive than replacing it. Your choice.

 

[Ronin]

I had the replacements done at 100k intervals on my '03 Tundra. Better than potentially ruining a motor or having it go out in the middle of nowhere. Think of it as replacing your tires - it's just part of the cost of running your rig!

 

[ski3pin]

"I had the replacements done at 100k intervals on my '03 Tundra. Better than potentially ruining a motor or having it go out in the middle of nowhere. Think of it as replacing your tires - it's just part of the cost of running your rig!"



Yes, it is maintenance. Although I do most of our own work - yup, replaced the timing belt on Julie's old Subaru Forrester at the recommended 100k - I follow the recommended maintenance schedule to give our vehicles the best chance for a long and fruitful life.

BTW, we replaced her Forrester with a new Subaru Crosstrek because they now use a timing chain that does not require replacement.

 

[Vic Harder]

timing belts are an absolute “must do” i’ve done a dozen myself. and seen the results of not doing them

 

[Happyjax]

I had mine go out on my Solara at 70,000ish miles. When I asked the mechanic about that because I thought the miles were much higher he said (I think) 90,000 or 8 years. It was 8 1/2 years old.

I was lucky there was no damage

 

[Vic Harder]

Funny thing... we used to have a 1998 Toyota Avalon. In the USA, it was 100k miles between timing belt changes. In Canada, 100k km. Same car. Mazda was the same way. Eventually the Canadian cars followed the US model and went to 160k km.

I like the belt design vs chains. Belts are typically easier to change, and cars that have chains with problems (BMW, Audi) have the chains buried on the firewall side and are a pain to get at when they do need work

 

[klahanie]

I just want to underscore the point that, speaking generally, timing belts may last a long time. The last one I replaced was on my DD, at 18 yrs old and 162K miles. A tensioner pulley had broken so I was into it anyway and replaced the belt also. The old one was in excellent condition and quite possibly could have out lasted the vehicle. It was also of excellent quality (oem).

Note, this was in a non interference design and a vehicle that does not travel remote, both important distinctions. Personally, I do agree with the "part of maintenance" outlook. I consider vehicles to be expensive no matter how you slice it and I don't take chances when we travel.

But I'm not like everyone. Someone more inclined to a "if it ain't broke, don't fix it" attitude may want to consider how long they plan on keeping the vehicle and for how many miles. And, if they are prepare to face the consequences of a breakage. These are common considerations that apply eventually to most vehicles.

 

[GT-Jim]

A guy I work with had a Jetta with a timing belt that had a tick over 100K miles. I reminded him to get his belt changed and a few weeks later he and his wife left for the in-laws and made it 60 miles and the belt broke. He's not a car guy and I don't think he understood the consequences. Jetta is an interference motor also, if you asked him what he would do I bet you know the answer. Granted it was an unfortunate coincidence and could have easily lasted longer than it did but it didn't.

 

[Wallowa]

Hey,

Thanks for all the input and it is appreciated. My conundrum is that my '05 Tundra only has only 41+K miles but is obviously 13 years old. The "time or distance" issue is not a simple one to resolve. No telling the condition of any component buried inside a motor; odd the serpentine exposed belt has no such "replace by" date and visually inspecting one is again a crap shoot.

Just had a 'recall' on our '10 Subaru Outback [wiper motor cover]; same same on replacing the timing belt @ 105K.

I would have gotten a 'life time' chain timing belt in the 6 cyl if I had know about "interference motor"... I asked what a new 4 cyl motor would cost if I lunched mine..$5K. Bet a new 4.7 in Tundra is a hell of a lot more expensive.

I will go on mileage with the Tundra, but will chicken out about 60K and pony up the bucks...new pulley, water pump and belt will be around $1K...

My personal opinion is this is a poor way to design a motor.

Phil

 

[ntsqd]

I had a '72 Pinto Wagon when I was young and it ate timing belts due to the crank pulley being worn and too expensive for me to replace at the time. I got so that I could do the whole job on the side of the road in about 15 minutes. Could buy a lot of belts for the $100 that I was quoted for that pulley!

That said, if you're already in there for some other reason and given the details mentioned above I wouldn't hesitate to replace it.

 

[wuck]

Funny thing... we used to have a 1998 Toyota Avalon. In the USA, it was 100k miles between timing belt changes. In Canada, 100k km. Same car. Mazda was the same way.

Maybe there was an ex-NASA employee was involved in the service manual??

 

[Vic Harder]

LOL!!

 

[carld]

If Toyota specifies 90k then the failure probably at 90k is probably less than 1%. You are probably good for 200k miles. When the water pump or tensioner look like a problem then do the timing belt.

 

[Vic Harder]

Carld, I respectfully disagree. The cost of NOT doing the timing belt is high. The cost of the belt/labor is minimal in comparison.

 

[carld]

Ya on my last Tundra I did the 90k maintainance at 180k then another one at 260k. You are right the concequence is dire but I'm an enganier "at least I think thats the way I think you spell it" and if the company says it might fail at 90k miles the probability is vary vary low, better than a half life and maybe more like 3 to 6 times. So I'm not saying that you should do it, I'm just saying don't worry too much. You are more likely to have a water pump or surpentine belt issue first.

 

[ntsqd]

I know of a specific engineering case that might offer some insight into Toyota thinking. First gen MR2 engine, a 4A-GE, had a Toyota set redline of 7800 RPM. Len Frank (for those of you who remember his by-line) asked a Toyota Engineer about that when the car and engine were first introduced, how long could the engine be expected to live if it could be spun up that fast. The answer was 100k miles, at least, when run at 7800. Imagine running an engine at 7800 RPM for 100k miles!
However, spun up to 8200 RPM and it's life span was about 20 minutes. Consequently the ECU soft limited at 7800 RPM (ask me how I know this) and only by deliberately down-shifting at speed could you get it past that. I don't think Len put this in his article on the car, but he told many of his friends about it. I was lucky enough to have briefly known him.

So, I wouldn't call the 90k service life a hard and fast rule, it has some tolerance. But I wouldn't make that tolerance too wide, Say 75kM to 110kM would be my own rule.

 

[klahanie]

>9,000K, 200K, >180K, 270-540K. Gee, pity the poor lay person faced with those variations

Perhaps Toyota simply chose 90K as an easy number for their dealer service depts to work with and one that they calculate will generate income from the greatest number of customers.

 

[ottorogers]

Definitely change the belt no matter the milage, these belts can deteriorate, I would never take the chance, because like you said, if the belt breaks your engine is finished (potentially), sure glad the new Tundra's have a chain, my old 4Runner had a belt (4.7 V-8), and when I did change the belt at 100,000 miles I changed both idler bearings and the water pump, cost was about $500 and worth it for peace of mind