Serpentine belt cracking

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

eradicator006

Full Access Member
Joined
Apr 18, 2009
Messages
175
Reaction score
2
Location
Canada
I just replaced my serpentine belt because it was severely cracked. There were vertical cracks 1/8" apart all around the ribbed side of the belt. I thought the OE belt was not supposed to crack? It only had 91,000km on it.
 

eradicator006

Full Access Member
Joined
Apr 18, 2009
Messages
175
Reaction score
2
Location
Canada
I know they wear out at about this mileage. I was just curious as to why it cracked when they aren't supposed to crack. The guy at napa was kind of surprised when I showed him my old belt.
 

speedracerbubba

Full Access Member
Joined
Oct 28, 2009
Messages
720
Reaction score
1
Location
408
Given enough time and use I have never seen a serpentine belt not crack.
My wifes saturn had the best belt I have seen when I replaced it at 80,000 miles. She does not drive that thing hard at all and rarely brings it past 3,500-4,000 rpm. The belt was starting to crack and had a few small spots missing in the teeth, but it was not bad at all. The radiator hoses were pretty soft, though.
 

LibertyTC

Well-Known Member
Staff member
Moderator
Joined
Oct 24, 2008
Messages
9,095
Reaction score
1,765
Location
B.C. Canada
The belt works hard, and the Kj's under the hood temps are not the coolest.
I know when I replace my serpentine, a new tensioner and Idler pulley will be installed too.
 

tjkj2002

Full Access Member
Joined
Dec 17, 2006
Messages
10,612
Reaction score
39
Location
Somewhere between being sane and insane!
I just replaced my serpentine belt because it was severely cracked. There were vertical cracks 1/8" apart all around the ribbed side of the belt. I thought the OE belt was not supposed to crack? It only had 91,000km on it.
That was not a OEM belt,it had been replaced before.The OEM belts on the KJ are EPDM and do not crack.Hope you replaced it with another EPDM belt from Gates or another OEM one,the other belts are not EPDM and will crack and wearout at about 30k-50k.
 

eradicator006

Full Access Member
Joined
Apr 18, 2009
Messages
175
Reaction score
2
Location
Canada
That was not a OEM belt,it had been replaced before.The OEM belts on the KJ are EPDM and do not crack.Hope you replaced it with another EPDM belt from Gates or another OEM one,the other belts are not EPDM and will crack and wearout at about 30k-50k.

The old belt said MOPAR on it in blue letters. I think the mopar logo was also there. New belt is a gates...at least that is what napa told me. The package said napa on it with no mention of gates.
 

speedracerbubba

Full Access Member
Joined
Oct 28, 2009
Messages
720
Reaction score
1
Location
408
That was not a OEM belt,it had been replaced before.The OEM belts on the KJ are EPDM and do not crack.Hope you replaced it with another EPDM belt from Gates or another OEM one,the other belts are not EPDM and will crack and wearout at about 30k-50k.

That is interesting. Gonna research that one to satisfy my curiosity.
 

tjkj2002

Full Access Member
Joined
Dec 17, 2006
Messages
10,612
Reaction score
39
Location
Somewhere between being sane and insane!
The old belt said MOPAR on it in blue letters. I think the mopar logo was also there. New belt is a gates...at least that is what napa told me. The package said napa on it with no mention of gates.
MOPAR has a value line of parts also,there value line belts are vinyl but the one that was supposed to be installed at the factory is a EPDM belt and should have had green lettering for the EPDM belt.
 

ptsb5a

Full Access Member
Joined
Mar 29, 2006
Messages
2,425
Reaction score
20
Location
Northern Alberta, Canada
That was not a OEM belt,it had been replaced before.The OEM belts on the KJ are EPDM and do not crack.Hope you replaced it with another EPDM belt from Gates or another OEM one,the other belts are not EPDM and will crack and wearout at about 30k-50k.

Not gonna argue dude but I call BS. I've owned my KJ since new and when I replaced the belt last summer, it was cracked and starting to peel bits of off the edges of the belt. Parts of it were about 3/4 the width of a new belt and it was craked through the ribs to the core belting material (nylon/poly??). The backside of the belt (not ribbed) still looked good with no cracks.
 

tjkj2002

Full Access Member
Joined
Dec 17, 2006
Messages
10,612
Reaction score
39
Location
Somewhere between being sane and insane!
Not gonna argue dude but I call BS. I've owned my KJ since new and when I replaced the belt last summer, it was cracked and starting to peel bits of off the edges of the belt. Parts of it were about 3/4 the width of a new belt and it was craked through the ribs to the core belting material (nylon/poly??). The backside of the belt (not ribbed) still looked good with no cracks.
Cannot vouch for export models but....................

here are picks of my original belt that came with my KJ,it's a EPDM belt with 30,000 miles and 8 years old(spare trail belt).
You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach


My current belt is the exact same part # as the OEM one,again EPDM.

http://www.gatesprograms.com/beltwear/beltwear
 

jnaut

Full Access Member
Joined
Apr 17, 2008
Messages
2,233
Reaction score
9
Location
Seattle
Maybe conditions affect it?

I'm not taking any side here because I'm no expert, but my belt is stock, has 86,000 miles on it, and looks brand new (had a date of like 6/13/03 on it). I even had a message about this a while back. I bought a new belt to replace the one I had, and it looked in perfect condition, so I left it on and stuck the new belt in my tool kit.

I'm torn as to whether I should even bother to put the new one on now...
 

eradicator006

Full Access Member
Joined
Apr 18, 2009
Messages
175
Reaction score
2
Location
Canada
Mine has a part # of 53013905AA. Lettering is white, not blue. Maybe EPDM cracks in extreme cold temperatures? I'm guessing it's our harsh Canadian winters that's causing it to crack.
 
Top