I replace mine the second I hear a squeak that is silenced with a yellow belt dressing crayon. This indicates the rubber is drying out. OR, the second I see a crack in the lands/groves of the belt, OR @ 70K. I check the belt every 3K when I change the oil/filter, rotate the tires, lube the aftermarket grease fittings, etc. NAPA has a life-time warranty on their premium belts. If it squeaks, replace it for free if you can do it yourself.

 

Hey 87 WhyJay! That's a really good response with good advice. Thank you.

 

https://www.familyhandyman.com/automotive/car-maintenance/serpentine-belt-how-to-check-for-wear/

They actually make a wear gauge to help you decide when to replace. I got mine free from Gates belts. I cannot seem to find where I asked for it. Saw it on eBay for $9.

 

They actually make a wear gauge to help you decide when to replace. I got mine free from Gates belts. I cannot seem to find where I asked for it. Saw it on eBay for $9.

They have the Dayco Awareness tool on eBay for $5 and free shipping.

 

Before any epic trip where a mechanical failure would ruin your day, or every 4 years.

 

Just replaced mine with a Gates from O'Reilly for @$45. I did mine at 115K and that was far too late....

 

I did my at 97k. The belt was in good enough shape to keep it as trail spare.

 

This. If you are questioning it, replace it. And if it's in good enough shape, keep it as a spare. They're easy enough to replace in the driveway/garage. Damn near impossible to change on the trail when you don't have a replacement.

-m

 

Did mine at 75K. Still looked good, but previous owner never really used it much (garage queen). Kept it as a spare. Do note; if you wheel much, do dirt roads, gravel, mud, etc. it will have an impact on belt life because crap can get tossed into it on the trail... making just going by mileage alone not the best indicator of wear.

 

Thanks for all the responses. They all make sense. I will at the very least buy a new one and carry as spare on our Summer trip, Florida to Tuktoyaktuk.

 

...our Summer trip, Florida to Tuktoyaktuk.

Holy Road Trips Batman!

I just googled that and from here where I am in Orlando to Tuktoyaktuk is 84 hours and nearly 5000 miles!

 

whats the procedure look like? Last serp belt changed was in my 4.0 ZJ and that was pretty simple. Hows this compare?

 

1/2 breaker bar clockwise slow.

 

5 years/75k miles seems like a good time to change it. Also whenever you replace the alternator or water pump.

I had one fail on a Grand Cherokee V8 at 56k miles(!) but the JK 3.6 belt seems more durable.

EDIT: the Service Manual states:
The accessory drive belt is designed to meet the 10 years / 150,000 miles durability requirements. Belt replacement is not recommended until this requirement has been met or damage was done to the belt.

 

I changed my belt at 100,000 miles. It was not giving me any problems but I was about to drive from Louisiana to Colorado and I did not want to take a chance on a belt breaking and leaving me stranded somewhere in west Texas or in New Mexico. I bought a replacement Gates brand belt on Amazon for $20.79.
https://www.amazon.com/dp/B000C2SJ5E/?coliid=I1UFZF5RPUP408&colid=399YPFG70MR7J&psc=1&ref_=lv_ov_lig_dp_it

 

I did mine at 70k while replacing the PS pump even though it had plenty of life left.

 

I changed mine at a little over 5000 miles. Didn't have much choice, it shredded while out on a trail near Sedona. So from me point of view, examine it frequently and _always_ carry a spare!