Just checking out the service manual coming up to 120,000km. It calls for replacement of serpentine belt but not the pulleys/tensioners. Are the pulleys/tensioners replacements required?, have people done it?, are they failure prone? Any comments.....

Cheerio
Brett

Depends on your nerve/level of concern and the actual condition of the pulleys. For either belt you do not "have" to replace the pulleys and tensioners if they are not leaking grease and the bearings have essentially no play. However, the timing belt pulleys and tensioner are a bit hard to get to and invisible during operation so it's worth considering doing the swap while you are in there. The serp belt is a different story as the pulleys and tensioner are quite visible and easy enough to replace, assuming you modify your fan shroud while doing the job the first time, so if they are solid I see no reason why you should automatically replace them as part of the process.

Of course the flip side either way is a bearing goes when a bearing goes and they can last forever or die right out of the box so you pays your money and take your chances. That said if you don't cheap out on bearings they should last just fine.

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Old mechanic tricks:

If you want some assurance about the tensioner pulleys, use a mechanics stethoscope and compare the sound you hear when you hold the probe on the bolt that mounts the pulley with the sound you get when the probe is on the engine head or block. A whining, rumbling, or grinding noise is not acceptable.
If you have a non contact, laser guided, thermometer, you can shoot the bearings in the pulleys and shoot the mounting bracket. A few degrees difference is OK, more than a few is not OK.

Agree with papaindigo, timing belt idlers and the tensioner are not easy to get to and risky to reuse, best to replace.

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Check them out. If bad replace.
If not ask yourself, do you have more time than money?
I replaced wheel bearings with crap bearings and now they are being replaced again.

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thanks guys.

When I did the timing belt I checked each of them. The ones I replaced either had a catch in them (failing ball bearings, or debris inside) or were extremely dry and spun too freely.. so I expected that they were in the process of failing.

I ended up replacing two of the three idlers with NAPA parts, and used a factory replacement for the fan mount (the big iron one in the middle). It looks like it's made for easy replacement of the bearing only - so if you had a good shop in town you could probably buy a quality part.

I expect you'd be pretty safe and relatively wise replacing them all by 150k.

Mark

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2005 Liberty CRD
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