Replacing Serpentine Belt--Is it Difficult?

[DanW]

Talked to the parts guy at my Jeep dealer yesterday and ordered the belt and priced the idler pulleys...I think I'm going aftermarket with the pulleys....anyway, he said he almost never sells those pulleys. He says they don't seem to fail on the Pentastar like they once did on older engines. He was surprised I wanted to order those. I told him it was cheap insurance and easy to do while already in there. (I did that on my 3.8 JK).

Anyway, has anyone actually had one of those pulleys fail? My good friend with 260k on his 2014 JK has replaced 2 belts but no pulleys and they are quiet as church mice. Just curious. Like I said, I'm replacing them...easy and cheap. But I'm curious if anyone has had one become noisy or fail.

I did have one, which was mostly plastic, fail on a 2004 Grand Cherokee. It came apart with no warning....no squeaking or wobble. I think in that case the plastic had become brittle with age. It was almost 21 years old. But it only had 120k miles on it.

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[wibornz]

Because I replaced the 4 idler pulleys too, requires you to remove the tensioner and the alternator + bracket.

Yup that take a little more time. I thought I was going to break the alternator bolts because they were on so tight.

 

[wibornz]

Talked to the parts guy at my Jeep dealer yesterday and ordered the belt and priced the idler pulleys...I think I'm going aftermarket with the pulleys....anyway, he said he almost never sells those pulleys. He says they don't seem to fail on the Pentastar like they once did on older engines. He was surprised I wanted to order those. I told him it was cheap insurance and easy to do while already in there. (I did that on my 3.8 JK).

Anyway, has anyone actually had one of those pulleys fail? My good friend with 260k on his 2014 JK has replaced 2 belts but no pulleys and they are quiet as church mice. Just curious. Like I said, I'm replacing them...easy and cheap. But I'm curious if anyone has had one become noisy or fail.

I did have one, which was mostly plastic, fail on a 2004 Grand Cherokee. It came apart with no warning....no squeaking or wobble. I think in that case the plastic had become brittle with age. It was almost 21 years old. But it only had 120k miles on it.

Yes, I had one fail and it threw the belt.......thats why I changed the belt on the edge of the road. We have done thousands and thousands of desert miles with alll the dust, a bunch of mud and deep water crossing too.

My Jeep has a hard life, but I do maintain it well.


Think like this.
Desert and water

Desert

The Jeeps are in the lower left corner. I did some climbing that day.

Mud

Then mud like this packs the radiator and idler pulleys fail.

Hundreds of water crossing like this probably don't help.
Just watch the first 30 seconds for a river crossing with water up to the windshield.

 

[stino]

Talked to the parts guy at my Jeep dealer yesterday and ordered the belt and priced the idler pulleys...I think I'm going aftermarket with the pulleys....anyway, he said he almost never sells those pulleys. He says they don't seem to fail on the Pentastar like they once did on older engines. He was surprised I wanted to order those. I told him it was cheap insurance and easy to do while already in there. (I did that on my 3.8 JK).

Anyway, has anyone actually had one of those pulleys fail? My good friend with 260k on his 2014 JK has replaced 2 belts but no pulleys and they are quiet as church mice. Just curious. Like I said, I'm replacing them...easy and cheap. But I'm curious if anyone has had one become noisy or fail.

I did have one, which was mostly plastic, fail on a 2004 Grand Cherokee. It came apart with no warning....no squeaking or wobble. I think in that case the plastic had become brittle with age. It was almost 21 years old. But it only had 120k miles on it.

I've had 5 pulleys fail (start whining) at this point, maybe I'm just unlucky or maybe its the desert wheellin'.

 

[DanW]

I've had 5 pulleys fail (start whining) at this point, maybe I'm just unlucky or maybe its the desert wheellin'.

Ok, sounds like the sand and dust may get up into the bearings, or at least that's best guess. You and @wibornz both run in those conditions and both suffered failures, so that certainly suggests why they failed. I don't get that deep into water or run in as much dust as you guys, but I do it on occasion. That's enough to convince me to go ahead and replace them.

I appreciate the info, guys!

 

[mwilk012]

Ok, sounds like the sand and dust may get up into the bearings, or at least that's best guess. You and @wibornz both run in those conditions and both suffered failures, so that certainly suggests why they failed. I don't get that deep into water or run in as much dust as you guys, but I do it on occasion. That's enough to convince me to go ahead and replace them.

I appreciate the info, guys!

Normal road drivers have these things fail all the time, it just takes a long time. Buying Mopar pulleys is crazy though, that’s why the parts guy doesn’t sell them.

 

[mrtm1970]

I bought them at Napa. I changed them at approx 126,000 miles. I had an idler pulley fail. So I changed the belt at the same time. Then a few weeks later doing maintenance on the Jeep, I replaced all of the pulleys while doing some routine maintenance at Trail Toyz shop in Alaska. The fine folks allowed me to use their shop to work on the Jeep before heading to the Arctic Ocean at Deadhorse Alaska. I rotated tires, swapped the idler pulleys out, put brakes on all the way around, changed oil and diff fluids, check the torque specs for the suspension and all steering components. Then let me use the shop on a Sunday while they were closed. There is no way that I can ever thank them enough.

Did you have to replace your alternator yet? Wondering it’s worth it to replace at 114k while I am going to be changing my belt and water pump…I guess I will be looking to change my idler pulleys too then

 

[alphawolff]

I replaced mine on the edge of the road in 20 minutes. Not sure how it took a couple hours. Are you guys using Crescent wrenches and Chanel lock pliers or what?

The trick with the tensioner is to slowly apply pressure to release it. The bigger the breaker bar the easier it will be. Mind you I do have the correct tools and a Milwaukee powered ratchet. If you are doing this at 100,000 miles, might want to check your idler pullies. I carry an extra belt and pullies. I have replaced idler pulleys that failed on the edge of the road.

Also note if you do remove the tensioner, the bottom bolt there is a bushing in there. It is easy to drop it and not notice it. Make sure you put the bussing back in. You have to remove the tensioner if you are replacing the pulley on the tensioner.

The E-torque is the hard one to do. The normal belt isn't that big of a deal

 

[wibornz]

Did you have to replace your alternator yet? Wondering it’s worth it to replace at 114k while I am going to be changing my belt and water pump…I guess I will be looking to change my idler pulleys too then

I have not. I have driven many vehicles past 200,000 miles without replacing an alternator. I have made probably 200+ river crossing and deep water crossing with the Jeep. Think like this. I crossed the river you see in the video 6 times that day. This is what risk taking looks like. I am 4000 miles from home and I have to drive the Jeep home..



or watch the first 30 seconds of this video.



Changing the alternator is not hard. The alternator if you have the towing package is like $450+ so I would not change it unless it is needed.

 

[stino]

Did you have to replace your alternator yet? Wondering it’s worth it to replace at 114k while I am going to be changing my belt and water pump…I guess I will be looking to change my idler pulleys too then

I had to replace mine at like 55k mi. I guess I was unlucky

 

[wazzabie]

I just did this, it's really not that bad. Took me a couple hours.

I also replaced the 4 idler pulleys, 3 of them (including the tensioner) with Gates metal pulleys. Mopar does suggest replacing the entire tensioner vs the pulley, but I've done it twice and it's been fine using strong loctite (only on the tensioner bracket idler). The tensioner takes a bit of technique, don't try to crank it like a bolt, just slowly put more and more pressure/weight on it until it eventually and slowly gives - it will. Once you figure it out its easy.

Hit me up if there's anything else I can help with

What is the quality like for the gates metal pulleys? Made in USA?

 

[stino]

What is the quality like for the gates metal pulleys? Made in USA?

I mean... it felt higher quality than stock to me and I've had terrible experiences with the mopar ones but was the bearings and not the pulley itself that went out. I've only run it for 5k mi or so, and its been fine.

I believe the ones I got were made in Korea

 

[Mjr.Crash]

On Alternators -- here's mine on a 21 JL 3.0 diesel with tow packadge an 134K on it .. my tensioner pully went out ... Wabbling and grinding noise . So before i bolt up my alternator again .. i spun it to ensure its not noisy or sticking but check the wobble ... WTF ..???

 

[Mjr.Crash]

Also what about the cracks in center ?

 

[mwilk012]

I would replace that alternator if it makes you feel more safe. It’s clearly wearing out, but not bad.

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