Replace Serpentine Belt Auto-Tensioner every time?

[The Critic]

According to this Gates bulletin, automatic belt tensioners should be replaced with every belt replacement:

http://blog.autoupkeep.com/wp-content/uploads/2009/08/Gates_BeltTensionersRole_Final.pdf

Per the Gates bulletin, noise from accessory drive belt systems are often caused by either pulley misalignment or the start of belt tensioner failure.

In the past, I have seen cars with slightly noise belts that were cured with a new belt only. However, lately, I have also seen a number of cars with badly worn belts that exhibited no noise at all.

Recently, I came across an Accord with a moderately worn serpentine belt that was making some squeaking during cold start-up. On this car, the tensioner pulley also had a borderline-excessive amount of play. Although the new belt has quieted the system completely, I have already obtained a new OE tensioner and plan to install it given what I’ve learned from the Gates bulletin.

Based on the information from Gates and your past experiences, is it truly necessary to replace the auto-tensioner with every serpentine belt replacement? Logically, tensioners should lose some effectiveness with age, so arguably a new tensioner should allow the new belt to have the same service life as the first one. However, it is possible that Gates is trying to sell more tensioners…

 

[bdcardinal]

I think its a little of both. On certain applications it is absolutely true, on others probably not.

 

[dparm]

Might as well. Tensioners are fairly cheap and you'll feel stupid if the tensioner fails a few months later. If there's a roller or anything similar, I'd suggest replacing that too.

 

[buster]

I agree, probably both and probably worth replacing both at the time of the job. That would be my .02.

 

[JHZR2]

IMO depends upon how tough it is to access, and how noisy/bad the belt system is. If Im changign a belt proactively, and its silent and fine, maybe not. If its noisy. the tensioner is bouncier, etc., then maybe yes.

 

[bigjl]

Originally Posted By: dparm
Might as well. Tensioners are fairly cheap and you'll feel stupid if the tensioner fails a few months later. If there's a roller or anything similar, I'd suggest replacing that too.


They are in most cases.

Except for some diesel Fords, they are over £100!

If there was no noises or vibration and the belt change was due to time/mileage rather than failure I would only change it if it was relatively cheap. Under £40/50.

But for the Fords previously mentioned I would leave the old one on.

Otherwise a multi belt job will cost the best part of £250.

 

[PandaBear]

Easy to change and only last a short time (i.e. 60k)? Probably not. Expensive to change and last 120k miles? Might as well.

 

[jdeare]

This definitely doesn't apply to all cars. But I replaced the belt and not the tensioner on my old Buick. I believe the cracking I saw was caused by age, not miles (my records show that I changed it in 2009 w/41,000 miles on it, at which point it was 8 years old).

I saw no signs of it going bad for another 30,000 miles, after which the trans forced me to dump the car.

 

[JTK]

I too would say it depends on the application. S-belts last such a ridiculously long time anymore and cost so much to have replaced for you, you may as well have the tensioner replaced too if it's an accessible, low cost item.

Joel

 

[Chris142]

We rarely replace the tensioner with a new belt. Unless the tensioner is hard to move or lopsided we let it go. My Jeep is @140K on it's original tensioner arm, I did replace the pully due to bearing noise.

 

[MONKEYMAN]

I just went through this scenario on a 99 SL2 with 216,000 miles. Noise when cold. The tensioner had 100,000 miles on it and I replaced it again. Then noticed grooves on idler pulley. That was cheap to replace and bearings were noisy. Also replaced the belt. If it is high mileage I would not forget the idler pulley if it has one...

 

[stephen9666]

I don't think I agree with Gates. Remember, Gates sells tensioners. Getting you to believe you need to change it every time, whether you really do or not, is to their advantage.

Just like oil companies telling you to change your oil every 3k. It's not needed much of the time, but if you do that you'll be buying more of their oil.

From my experience, pulleys wear out far more than tensioners. I've replaced the bearings in several idler and tensioner pulleys, but I've never actually replaced a full tensioner. I'm sure there are cars where tensioner failures are a common problem, but that must not be the case on any of the vehicles I've owned.

 

[Whimsey]

I guess I work backwards. My 2002 F-150 with 54,000 miles had the tensioner completely fail. So I had the original belt replaced at the same time

.

Whimsey

 

[mechtech2]

The tensioner guts are just a spring. It can be lubed . They work, or they are broken.
It is the PULLEY that is more potentially problematic. And you have other pulleys that are not tensioners.
Over 80k, and I'd consider new ones.

BTW, I grease mine. The end cap/seal pops off, and it is easy to grease. [there are usually TWO sides]

 

[Smoky14]

Originally Posted By: stephen9666
I don't think I agree with Gates. Remember, Gates sells tensioners. Getting you to believe you need to change it every time, whether you really do or not, is to their advantage.

Just like oil companies telling you to change your oil every 3k. It's not needed much of the time, but if you do that you'll be buying more of their oil.

From my experience, pulleys wear out far more than tensioners. I've replaced the bearings in several idler and tensioner pulleys, but I've never actually replaced a full tensioner. I'm sure there are cars where tensioner failures are a common problem, but that must not be the case on any of the vehicles I've owned.


And remember, Gates recommends this to professional mechanics who don't want come-backs..better to charge the average customer for a tensioner and have it be trouble free than have to have them come back again.

 

[The_Eric]

Originally Posted By: Smoky14
Originally Posted By: stephen9666
I don't think I agree with Gates. Remember, Gates sells tensioners. Getting you to believe you need to change it every time, whether you really do or not, is to their advantage.

Just like oil companies telling you to change your oil every 3k. It's not needed much of the time, but if you do that you'll be buying more of their oil.

From my experience, pulleys wear out far more than tensioners. I've replaced the bearings in several idler and tensioner pulleys, but I've never actually replaced a full tensioner. I'm sure there are cars where tensioner failures are a common problem, but that must not be the case on any of the vehicles I've owned.


And remember, Gates recommends this to professional mechanics who don't want come-backs..better to charge the average customer for a tensioner and have it be trouble free than have to have them come back again.


Absolutely! You beat me to it.

 

[KrisZ]

I'm not a mechanic so I try to minimize unneeded part replacements whenever possible. On my Mazda the tensioner was perfectly fine when it came to belt replacement, but the pulley needed to be changed.
If it were a timing belt job, idlers and tensioners would've been replaced.

 

[rslifkin]

I've replaced the tensioner pulley on the Jeep once, but the tensioner itself is still original. It still keeps adequate belt tension and I've got no slippage issues (other than an occasional chirp on a WOT shift due to the fast RPM drop). I'll probably replace it the next time I have it off for something, but it doesn't really need it.

 

[The Critic]

Originally Posted By: MONKEYMAN
I just went through this scenario on a 99 SL2 with 216,000 miles. Noise when cold. The tensioner had 100,000 miles on it and I replaced it again. Then noticed grooves on idler pulley. That was cheap to replace and bearings were noisy. Also replaced the belt. If it is high mileage I would not forget the idler pulley if it has one...


Don't use a Gates tensioner, they will rattle horribly...at least they did on my '96.

 

[TFB1]

Originally Posted By: stephen9666
I don't think I agree with Gates. Remember, Gates sells tensioners. Getting you to believe you need to change it every time, whether you really do or not, is to their advantage.


Bingo!!!

You guys are going to sell a product and not try to drum up business???

I have repl a few pulleys over the years due to being worn and/or noisy, and in approx 20 years seen one Ford tensioner fail... Hoopie, the 175K mi '96 F-150 I just bought has a new tensioner and idler, but second idler is original(and quiet)...