2000 Dodge/Plymouth/Chrysler Neon Serpentine Belt Tensioner Pulley Replacement
This page was created to chronicle my replacement of the serpentine belt tensioner
pulley on a 2000 Plymouth Neon. The Neon shown here is a year 2000 model equipped
with the standard 2.0L four cylinder engine and a manual transmission. It has not
been modified from stock form in any meaningful way. The vehicle has 123,000 miles on it.
This page is not meant as a guide on how to perform this job. Non-stock replacement
components are used, and some required steps may be omitted as obvious, or referenced
from other locations. If you chose to perform anything written here yourself, you
do so at your own risk.
A couple of months after replacing my timing belt last year, the car developed a whining
noise from the right side of the engine. Upon taking tension off of the serpentine belt,
the whining noise would diminish, so I concluded that there was something driven by the
accessory belt that was making the noise. Some further inspeciton with a mechanics stethoscope
revealed that the serpentine belt tensioner pulley was the culprit. Attempting to spin it freely
with my hand, it would not turn smoothly. I began to seek a replacement component and
a method to remove and replace it.
However after a lengthy search, I could not find a source for the part in question, nor could
I find a guide that would say precisely how the part was to be removed and replaced, so
I set out to do the job on my own.
Update!: I have recently discovered that Gates now sells an exact replacement for the serpentine
belt tensioner pulley used in this vehicle. Sold at NAPA Auto Parts (and anyone else who carries
Gates products) part number 36156.
The serpentine belt tensioner assembly is mounted on the engine mount plate. None of the fasteners that hold either the pulley or tensioning arm itself are accessible with the mount plate in the vehicle, so it must be removed. To see how to remove it, please read my timing belt replacement writeup as the same job must be performed there: Neon Timing Belt Replacement. Once you have the engine mount plate removed, you may begin to remove the pulley.
The engine mount plate removed
The pulley is held onto the tensioner by a torx bolt. Once the bolt is removed, the pulley can be lifted right up and off of the shaft it is seated on.
The pulley mounting location
See update above! An identical replacement pulley is available, rendering many of the next few steps unnecessary. Here is where I deviate from what would be standard procedure. For all of my searching, I could not find the official Chrysler replacement pulley. I could not find the part listed anywhere on dodgeparts.com, and I wrote to them and inquired whether or not the tensioning assembly was available as part of the engine mount plate. They answered that it was not. The pulley was also not listed on any aftermarket parts site that I could find. With all that in mind, I removed the old pulley and took it to my local NAPA Auto Parts and did my best to match it up. The closest thing they had available was a pulley that was nearly identical in diameter and mounting point size, but was almost 50% thicker than the original pulley. Having run out of options, I was willing to give it a try. (NAPA part number: NBH 38018 for anyone interested)
New on the left, old on the right
The first problem I ran into is that since the pulley is thicker, any lateral movement in it would cause it to rub against the tensioning arm, so I shimmed it upward a fraction of an inch with a very small copper washer.
Needed just a little more clearance
The second problem I ran into was a slight imperfection in the casting of the engine mount plate. While under normal circumstances the pulley would never make contact with it, I decided that would be a good idea to file it down flat to remove all doubt. The aluminum is soft and files easily.
Removed casting defect
With everything ready, I installed the new pulley on the shaft. With the increased width of the new pulley, it is a very tight fit to slip it over the shaft, but it can be done. With the pulley installed, I tightened down the torx bolt that holds it in place. I used blue threadlocker on it to insure that it would not vibrate free. From there, it is a matter of reinstalling the engine mount plate in the vehicle. Again, see my timing belt writeup for the procedure details: Neon Timing Belt Replacement.
The Finished Product
With everything reinstalled, the new pulley fits and functions. There is not as much clearance
between the outer timing cover and the pulley as there once was, but they do not come into
contact with each other. The car again runs beautifully and the old whining noise is gone.
If anyone can find the offical Chrysler pulley it would obviously be better suited toward
its own replacement, but I didn't have the time or budget to wait any longer. That whining noise
was chipping away at my sanity and needed to be taken care of.
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Page Last Updated: 10:41 PM 7/19/2005