g2020
Well-Known Member
It appears that the decoupler pulley on the alternator is not available as an individual part on the MOPAR eStore. Long story short, a dealer will replace the alternator with a new & expensive OEM alternator instead of repairing the existing one.
As already covered by @darkhorse13, the cheapest route is to buy an aftermarket decoupler pulley and a removal kit, also listed below, and do a DIY repair (excellent write-up). Also see posts by @darkhorse13 between post #21 and post #32 in this thread.
Part & Tool for Repairing Decoupler Pulley
- Both of the following items are available on Amazon or RockAuto, but Amazon has free shipping even for non-members
1. Litens 920080A Decoupler Pulley
2. Lisle 57650 Alternator Decoupler Removal Kit
- Other tools
Torque: At 6:29 in this video, NAPA recommends 65 ft-lbs of torque unless otherwise instructed by the manufacturer. Perhaps because the decoupler pulley on this specific alternator is not serviceable by a dealer, I was unable to find the torque for the decoupler pulley on the list of torque specifications. Like many people, I do not follow advice from Google AI without checking the source. With that said, the most frequent answer to the question of "torque for Litens 920080A decoupler pulley", from Google AI, is "65-80 ft-lbs".
This DIY repair is a good option, but I prefer to install a new alternator and then replace the pulley on the old alternator on my own time. It's never bad to have a spare alternator ready to go.
Important reminder: When replacing the alternator, always reset the Battery Sensor / IBS (MOPAR 68289207AC, formerly 68289207AB) and use fine-grit sandpaper to clean the terminals on each side of the Battery Sensor. Wear protective eyewear & gloves. The battery sensor is reset when it is disconnected from 1) the negative (-) terminal and 2) both of the negative cables. Separate the two negative cables and (use electrical tape to) keep them away from the negative terminal and each other. When rejoining negative cables, a few sparks are to be expected. Clean the terminals on each side of the sensor to maintain/restore a good connection. Also disconnect cables from positive (+) terminal (after negative) and keep them away from positive terminal. (For the main/storage battery, the positive (+) cables are connected as a single unit.) Reattach cables in reverse-order (positive first, then negative). Battery sensor and negative cables should be completely reassembled before being placed on negative terminal. After completion, "Battery Voltage" on instrument cluster display should be variable as expected.
- Credit for this advice on resetting the Battery Sensor goes to @Maximus Gladius
Also see attachment below: Decoupler Pulley Replacement Instructions.txt
- In the attached instructions, each step of the replacement process is described in detail
Alternator Options
- Confirm part number & amperage for the alternator on your vehicle
- OEM (New)
- OEM (Remanufactured)
- Aftermarket (New)
Cost: At a dealer, expect to spend between $500 (DIY using remanufactured MOPAR part) and $1,500 (dealer installation of new MOPAR part)
Other Belts & Pulleys
Question: What is good maintenance practice for the following parts (one belt, two idler pulleys, and one tensioner)? Replace before breaking? At what age/mileage/condition? Do the intervals vary by part?
Answer (summarized from Google AI): The serpentine belt and belt tensioner should be replaced at the same time. The two idler pulleys can last longer, but idler pulleys are included in serpentine belt & belt tensioner kits and are also frequently replaced at the same time. Also, replacing only the two idler pulleys more frequently can't hurt, as this reduces the risk of failure of these parts. General replacement guidance is between 50,000 and 100,000 miles. Replace these parts ASAP if they show signs of wear.
Diagram of 3.6L Pentastar V6 Serpentine / Drive Belt System
On the Wrangler sister site, Upnarms posted a good diagram of the serpentine belt, pulley, & tensioner system.
Prices of Belt Tensioner, Serpentine Belt, and Idler Pulleys
- First price listed is from RockAuto
- RockAuto is used because the parts info is well-organized
- Other sites, including Amazon, may display search results for parts that do not fit
- These parts are usually replaced at the same time (based on what I've read online)
- I was unable to find a serpentine / drive belt kit, for the Gladiator, that includes all four parts
Four (4) parts: Belt tensioner, serpentine belt, idler pulley (grooved), & idler pulley (smooth)
Recommendation: After hours of researching these drive belt system parts, I have concluded that it is best to stick with MOPAR. As a very conservative estimate, an idler pulley is rotated about 62 million times per year (2,000 rpm X ratio of 2.6:1 X 60 minutes X 200 hours on the road per year). When a part makes that many revolutions, even the slightest difference in precision/fit can have negative consequences.
With that said, these were my findings on January 13, 2026:
Belt Tensioner
$125.79 MOPAR 5281453AB, $141.45 on MOPAR eStore
- No aftermarket brands listed on RockAuto for belt tensioner
Key for Belt & Pulleys:
1. Serpentine belt
2. Idler pulley (grooved)
3. Idler pulley (smooth)
n/a = not available / not listed on RockAuto
Belt & Pulleys
1. $48.79 MOPAR 5281454AA, $52.67 on MOPAR eStore
2. $48.79 MOPAR 68459077AA, $49.51 on MOPAR eStore
3. n/a MOPAR 68459078AA, $9.78 on MOPAR eStore (smooth idler pulley listing #1)
3. $31.79 MOPAR 5281821AA, $31.74 on MOPAR eStore (smooth idler pulley listing #2)
1. n/a LITENS (no serpentine belt listed on RockAuto)
2. $19.00 LITENS 900149A ***Original Equipment Manufacturer***
3. $22.79 LITENS 900704A ***Original Equipment Manufacturer***
1. $30.99 GATES K060854 (popular part)
2. $32.79 GATES 38082 ***Pulley Only*** (popular part)
3. $19.28 GATES 36816 (popular part)
1. $32.79 CONTINENTAL 4060852F
2. $26.79 CONTINENTAL 49073 (popular part)
3. $11.56 CONTINENTAL 49173 ***Includes Hardware***
- Not shown: DAYCO, ACDELCO, and some other brands
As already covered by @darkhorse13, the cheapest route is to buy an aftermarket decoupler pulley and a removal kit, also listed below, and do a DIY repair (excellent write-up). Also see posts by @darkhorse13 between post #21 and post #32 in this thread.
Part & Tool for Repairing Decoupler Pulley
- Both of the following items are available on Amazon or RockAuto, but Amazon has free shipping even for non-members
1. Litens 920080A Decoupler Pulley
2. Lisle 57650 Alternator Decoupler Removal Kit
1. 10MM FEMALE HEX (rotate male end using 11mm socket, 3/8" ratchet, and pipe extension; 7/16" socket will also work)
2. 17MM HEX (keep this tool stationary using a long 19mm box wrench; a long 3/4" box wrench will also work)
- Other tools
- A drill, a 1/8" drill bit, and a hole punch or pick are required to remove dust cover from old alternator
- To REMOVE decoupler pulley, rotate the socket in the direction of the ARROW stamped on the alternator (direction of rotation of alternator shaft) while keeping the box wrench stationary
- After removing old decoupler pulley, use small wire brush to clean threads of alternator shaft if necessary
- Before removing the hex tools and installing the new dust cover, reset the spring in the decoupler pulley by A) holding the decoupler pulley firmly in place with your hand, and B) using either of the hex tools to rotate the alternator shaft twice in the direction in which the decoupler pulley was installed (counterclockwise in this case); see 5:06 in this video by Advance Auto Parts and Litens, in which they demonstrate using an alternator with a shaft that rotates in the opposite (clockwise) direction from that of the alternator installed on a Gladiator
Torque: At 6:29 in this video, NAPA recommends 65 ft-lbs of torque unless otherwise instructed by the manufacturer. Perhaps because the decoupler pulley on this specific alternator is not serviceable by a dealer, I was unable to find the torque for the decoupler pulley on the list of torque specifications. Like many people, I do not follow advice from Google AI without checking the source. With that said, the most frequent answer to the question of "torque for Litens 920080A decoupler pulley", from Google AI, is "65-80 ft-lbs".
This DIY repair is a good option, but I prefer to install a new alternator and then replace the pulley on the old alternator on my own time. It's never bad to have a spare alternator ready to go.
Important reminder: When replacing the alternator, always reset the Battery Sensor / IBS (MOPAR 68289207AC, formerly 68289207AB) and use fine-grit sandpaper to clean the terminals on each side of the Battery Sensor. Wear protective eyewear & gloves. The battery sensor is reset when it is disconnected from 1) the negative (-) terminal and 2) both of the negative cables. Separate the two negative cables and (use electrical tape to) keep them away from the negative terminal and each other. When rejoining negative cables, a few sparks are to be expected. Clean the terminals on each side of the sensor to maintain/restore a good connection. Also disconnect cables from positive (+) terminal (after negative) and keep them away from positive terminal. (For the main/storage battery, the positive (+) cables are connected as a single unit.) Reattach cables in reverse-order (positive first, then negative). Battery sensor and negative cables should be completely reassembled before being placed on negative terminal. After completion, "Battery Voltage" on instrument cluster display should be variable as expected.
- Credit for this advice on resetting the Battery Sensor goes to @Maximus Gladius
Also see attachment below: Decoupler Pulley Replacement Instructions.txt
- In the attached instructions, each step of the replacement process is described in detail
Alternator Options
- Confirm part number & amperage for the alternator on your vehicle
- OEM (New)
1. Engine Generator - Mopar (56029803AA) $563.50 on 2026-01-10; 240A alternator (price on MOPAR eStore before tax, core deposit of $75, and shipping)
- Verified: Part number on original alternator is 56029803AA, and amperage printed on window sticker is 240A
- OEM (Remanufactured)
1. Engine Generator - Mopar (R6029803AA) $366.85 on 2026-01-10; 240A alternator (price on MOPAR eStore before tax, core deposit of $75, and shipping)
- Aftermarket (New)
The following option is not recommended: See note below.
1. 2020 Jeep Gladiator Alternator 240A 12V Counterclockwise 6-Groove Pulley A-Premium APALT1224 $253.95 ($272.36 after tax & free shipping on partsgeek.com)
- The DriveBolt (220A) and reconditioned (180A) options, that I found online, do not meet spec in my case
Note: First, they sent me part number ALT21025-C instead of APALT1224. ALT21025-C is so new that there is no info on the A-Premium website and I was unable to confirm specs. Next, the alternator was damaged during shipment because it was not packaged properly (original box and a single sheet of thin bubble wrap). I returned this alternator and bought a remanufactured alternator (R6029803AA) from the dealer.
2. WAI GLOBAL 21025N 240A $279.79, sold by RockAuto and other online retailers
Cost: At a dealer, expect to spend between $500 (DIY using remanufactured MOPAR part) and $1,500 (dealer installation of new MOPAR part)
Other Belts & Pulleys
Question: What is good maintenance practice for the following parts (one belt, two idler pulleys, and one tensioner)? Replace before breaking? At what age/mileage/condition? Do the intervals vary by part?
Answer (summarized from Google AI): The serpentine belt and belt tensioner should be replaced at the same time. The two idler pulleys can last longer, but idler pulleys are included in serpentine belt & belt tensioner kits and are also frequently replaced at the same time. Also, replacing only the two idler pulleys more frequently can't hurt, as this reduces the risk of failure of these parts. General replacement guidance is between 50,000 and 100,000 miles. Replace these parts ASAP if they show signs of wear.
Diagram of 3.6L Pentastar V6 Serpentine / Drive Belt System
On the Wrangler sister site, Upnarms posted a good diagram of the serpentine belt, pulley, & tensioner system.
Prices of Belt Tensioner, Serpentine Belt, and Idler Pulleys
- First price listed is from RockAuto
- RockAuto is used because the parts info is well-organized
- Other sites, including Amazon, may display search results for parts that do not fit
- These parts are usually replaced at the same time (based on what I've read online)
- I was unable to find a serpentine / drive belt kit, for the Gladiator, that includes all four parts
Four (4) parts: Belt tensioner, serpentine belt, idler pulley (grooved), & idler pulley (smooth)
Recommendation: After hours of researching these drive belt system parts, I have concluded that it is best to stick with MOPAR. As a very conservative estimate, an idler pulley is rotated about 62 million times per year (2,000 rpm X ratio of 2.6:1 X 60 minutes X 200 hours on the road per year). When a part makes that many revolutions, even the slightest difference in precision/fit can have negative consequences.
With that said, these were my findings on January 13, 2026:
Belt Tensioner
$125.79 MOPAR 5281453AB, $141.45 on MOPAR eStore
- No aftermarket brands listed on RockAuto for belt tensioner
Key for Belt & Pulleys:
1. Serpentine belt
2. Idler pulley (grooved)
3. Idler pulley (smooth)
n/a = not available / not listed on RockAuto
Belt & Pulleys
1. $48.79 MOPAR 5281454AA, $52.67 on MOPAR eStore
2. $48.79 MOPAR 68459077AA, $49.51 on MOPAR eStore
3. n/a MOPAR 68459078AA, $9.78 on MOPAR eStore (smooth idler pulley listing #1)
3. $31.79 MOPAR 5281821AA, $31.74 on MOPAR eStore (smooth idler pulley listing #2)
1. n/a LITENS (no serpentine belt listed on RockAuto)
2. $19.00 LITENS 900149A ***Original Equipment Manufacturer***
3. $22.79 LITENS 900704A ***Original Equipment Manufacturer***
1. $30.99 GATES K060854 (popular part)
2. $32.79 GATES 38082 ***Pulley Only*** (popular part)
3. $19.28 GATES 36816 (popular part)
1. $32.79 CONTINENTAL 4060852F
2. $26.79 CONTINENTAL 49073 (popular part)
3. $11.56 CONTINENTAL 49173 ***Includes Hardware***
- Not shown: DAYCO, ACDELCO, and some other brands
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