Accessory Drive Belt Maintenance?

[EddieC]

Should the engine accessory drive belt be routinely changed?

 

[Doubeleive]

Should the engine accessory drive belt be routinely changed?

unless you are talking about a k2xx then the gmt900's only have a serpentine belt & ac belt and yes they should be changed, probably not as often as the dealer will try to talk you into though, it's easy money for them.
but you can safely go a long ways, my preference is to change them about every 50k
if yours looks cracked or has edge wear or thread coming out of the seams then it's probably time for a new one.

 

[Geotrash]

unless you are talking about a k2xx then the gmt900's only have a serpentine belt & ac belt and yes they should be changed, probably not as often as the dealer will try to talk you into though, it's easy money for them.
but you can safely go a long ways, my preference is to change them about every 50k
if yours looks cracked or has edge wear or thread coming out of the seams then it's probably time for a new one.

Book maintenance interval is 100K. I change mine every 50K or whenever I have to remove it for something.

 

[mikez71]

I've seen mention of the ribs wearing out on newer belts before you see cracking/fraying.
Someone linked it before, a belt wear guage that you hold against the ribs. I guess the wear is not super obvious...

So I plan to throw my new belt on soon. I left it off figuring my original was in good shape, but I suspect it's due since everything else was original that it's connected to..

 

[Joseph Garcia]

I would suggest a 50K interval, unless unusual wear is observed. Also, consider changing out the tension pully as well, when changing the belt, as the spring tension decreases over time, and it is a relatively inexpensive part.

 

[Fless]

Pack your used serp belt along in case you need one in an emergency.

 

[EddieC]

Thanks all.
It appears that most of the recommended intervals have past so at 120,000 it's overdue.

 

[EddieC]

The main belt doesn't look bad other than glazing but the ac belt has chunks missing.
Funny that Rock Auto order ships from my state so that should be quick.

 

[91RS]

Yes, they should all be replaced at 100k.

 

[petethepug]

More precisely replace w/ a Gates green guaranteed for life kit or OEM. If you lose an accessory belt on a downhill mountain road your gonna have to drive into the side of the mountain to stop.

You’ll lose the power brakes & power steering & won’t be able to see from the steam of the motor overheating due to water pump getting kneecaped.

Power steering and brakes supplies about 90% of the leverage / power assist. You’ll snap the brake pedal before you get this 3T monster to stop.

 

[EddieC]

Here they are at 120,000 miles and 16 years. The camera macro pictures are much more telling than the naked eye sees.
The AC belt was much worse and used less. Not sure that makes sense.

It's a very easy job. More effort was needed to get the bottom splash cover on because of the front bolts into a pipe section than to actually change the belts.

Followup question though; how much effort should the tensioners be giving back in the process?
I'd seen some videos and it appeared that the guys were busting a gut to keep tension off the belts while changing.
I just used a standard 8" ratchet and it was a breeze, just a second thought in the whole thing.

 

[Geotrash]

Here they are at 120,000 miles and 16 years. The camera macro pictures are much more telling than the naked eye sees.
The AC belt was much worse and used less. Not sure that makes sense.

It's a very easy job. More effort was needed to get the bottom splash cover on because of the front bolts into a pipe section than to actually change the belts.

Followup question though; how much effort should the tensioners be giving back in the process?
I'd seen some videos and it appeared that the guys were busting a gut to keep tension off the belts while changing.
I just used a standard 8" ratchet and it was a breeze, just a second thought in the whole thing.

I replace the tensioners and idler pulleys every time I change a belt. The bearings barely outlast a belt in my experience.

 

[tom3]

Those small pulleys rotate at two or three times the RPM of the crank driver pulley so be sure to check those. Should rotate nice fluid smooth and quiet. Any doubt replace with a good name brand item. Not a good place for a cheap China bearing.

 

[EddieC]

So beyond the obvious bearings, how does one know about the spring tension on the belt?

 

[Doubeleive]

So beyond the obvious bearings, how does one know about the spring tension on the belt?

aside from using some kind of gauge, then no telling

 

[petethepug]

It was a cheap (not USA) idler pulley made by a (not USA) company that allowed the accessory belt to come off at 50+ down hill, off a highway, to a intersection I couldn’t turn into or stop at.

My 3T YXL Denali had 5 teens inside and we could of all been killed because of a cheap $7 idler pulley threw the belt. My apologies is this is unrelated to the post. My point is that accessory belt is life or death at highway speeds controlling the steering, brakes and engine cooling. I do mine every 50k after that experience and only use the Gates green belt kit.

 

[EddieC]

aside from using some kind of gauge, then no telling

Let's put it a different way.
Not being interested in an actual number, how do we know if the belt is tight enough indicating that the tensioner is not worn to the point of not being effective enough?

 

[j91z28d1]

Let's put it a different way.
Not being interested in an actual number, how do we know if the belt is tight enough indicating that the tensioner is not worn to the point of not being effective enough?

most simple answer? is the belt slipping? if not, it's tight enough.

if you hear squealing from slipping, or find black rubber dust on stuff around pulleys it's not. but to be honest, the tensioner isn't much more than the pulley on it. if you're worried about it. Just buy a new one with the new pulley.

 

[Geotrash]

Let's put it a different way.
Not being interested in an actual number, how do we know if the belt is tight enough indicating that the tensioner is not worn to the point of not being effective enough?

I’m sure there is a spec but I have no idea what it is. Mine move relatively easily with a ratchet also.

 

[Doubeleive]

Let's put it a different way.
Not being interested in an actual number, how do we know if the belt is tight enough indicating that the tensioner is not worn to the point of not being effective enough?

bottom line without a gauge and a spec to reference then just consider it a wear item and replace it, usually if there is a problem with it then it's starts making noise.
my guess is they might typically go 100k, maybe longer. I think I replaced mine once on this truck probably around 100k just because it was questionable at that mileage to me. now I am at 165k or so and I haven't heard any noises lately. The pulley seems to not last as long probably 60-80k or so on oem, aftermarket not so much
the pulley I have replaced at least 3 times, first one I bought a decent name brand aftermarket and that didn't make it very far so I bought what I thought was a oem, but the finish wore off in nothing flat and I thought that was wierd so I bought another oem and even after a good while it still has at least some of the black finish on it and no issue's so far.