Ok, all you OCD maintenance mudder folk have talked me into it. (With pics)

[BullElk]

You're obviously welcome to maintain to your own level of satisfaction and nobody really has any say so in it.

But I would say this: if I was in the market, and a seller had a truck with grossly overdue maintenance items like TB, that truck would absolutely not be in my search group any longer. OCD and unnecessary expenses aside, it is very telling to me when scheduled maintenance isn't done. I know you keep your trucks forever so no concern there, but to anyone else reading and feeling the same: don't do this and then expect high interest from folks who know better.

I agree and certainly use those thoughts when making the deals I do.

 

[NE Snowman]

Im one of the OCD guys and I thought this was great, I bought both my 4Rs well over 170k on OG belts. Allowed me to lower the price is all. Good to see just how long these pumps and belts will go. Thanks for the test samples

 

[Rhetoric]

I am OCD about timing belts. I also have a VVTI engine.

The PO replaced the belt and water pump in my truck at 220k miles in 2021. Kept the tensioner, idler pulleys, and fan bracket.

It hurts my OCD but I have 266k on it now…

I have budgeted for a full service next year by my OCD LC mechanic. Its a job I could do, but time is always my issue.

 

[97 AZ LC]

Both million mile Tundras needed only one water pump over the million miles, though it's not clear exactly when the originals failed - 500k or 950k?. Toyota doesn't want you changing the water pump with the timing belt, only inspecting it. They want you closely monitoring your coolant level. For all practical purposes repair shops have to change the water pump - looks bad if it fails soon after the timing belt job.

 

[Rednexus]

Here is an OE belt I pulled off a buddy's 2002 Tundra at 132K or so, in 2022. It was starting to fray. I'm sure it would have gone some distance longer, but it was definitely compromised.

What was interesting is just how much better the Tundra ran after the new belt. It sounded better (like my VVTI 2UZ) and had more power. We did nothing else to the motor that would have affected the power (just the T-belt and fluid baselining). I think the OE belt had stretched at/beyond what the tensioner could take up and caused the rig to have sloppy cam timing. That situation would have only worsened as the belt stretched more and the cam timing got even sloppier.

Having broken a T-belt on a vehicle before (Subaru EJ25 with a counterfeit eBay belt labeled as "OE"), it's not something I'd want to have happen again. The rig was totally dead and I have to get it towed home after pushing/coasting it about half a mile to get to a good pull-off. The Subie was an interference engine and bent all 16 valves. I pulled the motor, put in and lapped all 16 new valves, replaced the belt, and it's still going today. But, it sure made for a pretty terrible day in the woods (I was blasting down gravel roads in the middle of nowhere), and a very expensive tow home. Had I not been on top of a ridge with service, I would have been walking for several miles to call a tow truck. If it breaks say on a full-throttle merge into interstate traffic, you'd potentially be in a dangerous situation. Even on a non-interference engine, I'd rather just do it at the maintenance interval and not have to worry about it.

 

[rexington14]

FWIW my truck's water pump leaked well before the 90k mile interval it should have lasted. Although I suspect it was likely due to a parts quality issue. Per the service records it was a Gates aftermarket kit that the previous owner had an independent shop install right when the truck hit 90k miles.

 

[97 AZ LC]

There's so many advantages to timing belts - they don't stretch (good ones), they are quiet, they are inexpensive and easy to replace. Timing chains inevitably stretch (elongate) with wear and throw the engine out of time. They are noisy, more expensive and much harder to replace. That said I would never want a timing belt on an interference motor, and I would never want a timing chain on a non-interference motor like the non-VVT 4.7L. You haven't had real car problems until you've had timing chain issues on an expensive, unrebuildable, interference German V8.

 

[BullElk]

Never heard of any 80 series needing to change their timing chains.

 

[Rednexus]

I also despise timing chains. They are noisy and, IMO, make the motor feel slow-revving. A prefect example is a Subaru EJ25 compared to a FB25. The FB makes a noisy racket and sounds like a poorly-maintained sewing machine, compared to the EJ which is a great sounding motor. Other timing chain V8s - say the Ford modular SOHC motors - certainly have their problems.

Toyota might make a better chain than domestics, but I'd still pick a belt every time. It also forces you to change the coolant and WP at prescribed intervals, which may be why the UZ last so long.

 

[MongooseGA]

There's so many advantages to timing belts - they don't stretch (good ones), they are quiet, they are inexpensive and easy to replace. Timing chains inevitably stretch (elongate) with wear and throw the engine out of time. They are noisy, more expensive and much harder to replace. That said I would never want a timing belt on an interference motor, and I would never want a timing chain on a non-interference motor like the non-VVT 4.7L. You haven't had real car problems until you've had timing chain issues on an expensive, unrebuildable, interference German V8.

W126 560SEL owner here, those chains and guides are no joke. I had my chain replaced recently at 130k and it wasn't terrible, but the guides were shot and if they went, it would have been end of the engine. My 350k mile W123 300D had quite a bit of stretch when I had that chain done around 320k.