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Serpentine belt ran backwards?

6.4K views 19 replies 12 participants last post by  rep-tile  
#1 ·
The Jeep dealer noticed the serpentine belt was ran backwards. When I got home I checked and the fan is blowing toward the engine bay. It basically looks like someone routed it for the 4.0 and not the 4.7. I haven't had any issues with it, but what could this affect?

Are there reasons people switch the direction or is this something I need to fix right away?

Link to belts: http://www.wjjeeps.com/serpentine.htm
 
#6 ·
dealer to customer: " somehow your belt is not installed correctly and may cause damage"
customer to dealer: "it is? I never had any problems"
dealer: "oh yes sir, this is bad but we can take care of it for you, your estimate is around 200dollars for belt and labor"

hmm, I wonder if this is what was trying to transpire?
 
#9 ·
No. If any of you have any engineering mindsets, you'd understand how the water pump, fan, etc can be made to run in reverse. I don't have the Jeep at the moment, but all you need to do is look at the 4.0 routing of the belt and apply it to the 4.7.

Smart *** comments not appreciated. Have you ever added a cog to a another cog wheel? Notice how the DIRECTION of the last wheel changes? Pretty simple stuff.

For example, if I run the belt OVER the A/C compressor instead of under it...guess what happens? THE DIRECTION CHANGES.

Do you get it now? Jesus.
 
#11 ·
First off I didn't give a smart *** response. The wayy it was worded was the belt was running backwards not the accessories. As I said route it how ever you want the harmonic balance only runs one way so it would be impossible for the belt to run the opposite. And at the same time I would like to see you change the routing with the stock belt in order to reverse any accessory direction.

Sent from my SM-S820L using Tapatalk
 
#12 ·
If the grooves are on the grooved pulleys and the smooth on the smooth pulleys, then it won't matter how you try to route the belt, all accessories will turn the proper direction. The only way to make anything turn a different direction would be having a ribbed side on a smooth pulley or vice versa, but that's only if the ribbed side is being driven by the ribbed crank pulley. Of course if the flat side is on the ribbed crank pulley, all other points of contact will be the opposite of normal, but accessories would still turn proper direction.

So either the belt was flipped so all grooves were on smooths and all smooths were on grooves, or the dealer has completely fabricated a story or is just very very incompetent.

Edit- it is possible on some engines to route the belt differently, while still driving all accessories, but the tensioner would not be providing enough tension.
 
#20 ·
I suspect PO needed to replace the belt in an emergency type situation and could not find one the correct length and made it work with a different belt. Some folks are just that talented.