At what point would you proactively replace all pulleys and the belt tensioner?

So I’ve got a 2014 TRD with the V6. I replaced the serpentine when I bought it at 92k mile but I’m just about to turn 150xxx miles on the clock. So I’m going to replace the belt again (I’m a little anal about maintenance) and was wondering at what point do the pulleys and belt tensioner go bad? Easy enough to do and I’ll be in there...so looking for some advice.

 

There is no way to predict when a bearing will go. You might put in a new one and have it fail in 50K. There are trucks out there with 250K and original bearings. Just do what you are doing, and stay on top of things. Check the tensioner for play and smooth operation when you change belts. If the belt goes round and round without wobbling or squealing you are good.

 

There's really no set mileage, if they all spin smooth with no noise or play you should be good. On the tensioner you also have to check for play in the bushing which would cause belt alignment issues. If everything checks out you should be good, if in doubt replace it but generally you will get a noise before an idler bearing totally fails.

 

Sounds good. I’ve done this in chevys just to be safe every so often. Had an S10 that stranded me mid winter (that sucked).

 

My truck has 235k on the clock, just replaced the tensioner as it was starting to get a little weak, (this job sucks do your VVT-i screens when you do it) checked my pulleys while I had the belt off, they're not the worst ever (can't hear them making noise when the truck is running) but they are starting to roar a little turning them by hand and they spin too freely it's time.

Truck saw almost exclusively pavement for the first 180k then has gradually seen more and more dirt in the last 3 years and 50k.

 

See item #12: https://www.gatestechzone.com/en/problem-diagnosis/accessory-drive-system/micro-v-belt-wear-symptoms
Nowadays the EPDM belts don't crack with age, they lose material and thin down, which could only be checked with a profile gauge if you don't replace at fixed intervals.

Back when Toyota engines had timing belts (e.g. 2009 4Runner V8), the timing belt interval was 90k / 9 years. Usually it was sensible to replace the serpentine belt, idlers, tensioner, coolant, thermostat and water pump at the same time to save on labor cost. That's still a sensible interval now.

 

In rust free california I had to replace two at around 110,000 and the other two (just tentsioner pulley not tensioner) at 140k. At 140k only the tensioner pulley had play but I decided to swap the other one I didn’t change the first time round again.

Definitely just do them all at once and if your tensioner is still fine - just get the Febest tensioner pulley or the easy to source koyo replacement bearing.

 

By the way, all these intervals in the booklets assume on-road use only. If you wade through water or mud, some the pulleys could be gone in a year, but that's the cost of having fun. I carry a spare belt in my trail kit.

 

Never,until they go bad.

 

Personally, i just keep a few of each bearing on the shelf at all times so that when they fail I can just pull the pully, pop out the bearing, press in a new bearing and be on my way in about 20 mins The bearings are only like $20 each. cheap enough to keep on hand

 

First time I did my belt and 3x pullies was at 150k-ish. No plan to do them again until they're squealing

 

You're in a Tacoma now....no worries. Actually I may consider changing it on the 2nd gen later this year when I change plugs for the second time. That one is approaching 100k miles. I think the first gen we had I had the shop replace all the belts at 175k or so along with timing belt, different maintenance than 2nd gen.

 

Just replaced the belt and three idler pulleys at 180000 because of a whining sound. Did not replace the tensioner pulley or assy. The idler pulley nearest the ground was the culprit.
To address the question about preventative maintenance. Mine was whining for a couple thousand miles so there seems to be plenty of time to get it fixed before total failure. It did make sense to me to do all three pulleys and replace the belt while I had easy access. If the tesioner pulley starts to whine I plan to replace just the bearing.

 

Can you elaborate on the bearings? What bearings are you purchasing, and where are you getting them?

 

I will replace the set when it gets noisy, or at 250k, whichever comes first lol. My setup is all original with 166,000 miles but I've taken the time to grease the pulley bearings (PM) when the front of the engine was exposed for a water pump replacement. I agree that the life of the accessory drive system depends on a lot of factors that people have stated, also including your general environment (snowy, ice/salty, dusty) and storage (garaged or outdoors).

 

Replace the belt every 100k due to wear as described above, and keep the old belt in the truck just in case. Pulleys dont bother till they get loud.

 

read through this thread, alot of good info for bearings

https://www.tacomaworld.com/threads...s-gates-reference.516475/page-3#post-21988181

 

LOL - you think that being in a tacoma will prevent him from getting stranded?

idler pulleys are one of the things that DO have a tendency to go out early on these trucks, as do wheel bearings, door lock actuators, carrier bearings, etc.

Two of my pulleys had noticeable play before they started making noise. If they have play I’d replace them - and since you are replacing one - just do the set....

 

I see your point. I suppose if they look worn and loose then it may not hurt to change them out. I'm also kind of don't like to start throwing parts in something just for the sake of maintenance. A person could get a brand new defect right out of the box and be broke down a week later. If that concerned buy those spare parts and have them on hand in the back seat along with a 10 and 12 mm wrench

 

i feel you on that. I guess I just wish I had replaced all of mine the first time so I didn’t have to just go in a couple oil changes later for the rest. Now I definitely wouldn’t start replacing other parts on a whim - but in the case of something like idler pulleys where there is a well regarded aftermarket (maybe better than OEM in the gates pulleys) and I can get the set cheaper than them individually - I’m gonna pull the trigger every time. And when I’m already under the truck with the belt loose and a 14mm socket in my hand.... yeah...

edit: that last sentence was uncomfortable to read a second time... lol