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If you own a Chrysler 300, the transmission cooler line is a small component that plays a big role in protecting the transmission from overheating and premature wear. Choosing the right cooler line can prevent leaks, maintain proper fluid temperature, and help avoid costly repairs down the road. This guide highlights seven shortlisted transmission cooler lines chosen for fit accuracy, durability, and leak resistance. Read on to understand the factors we considered and what to look for when selecting a replacement line.
Looking for other parts? See all Chrysler 300 parts & accessories.
Top Picks at a Glance
| Best overall The best all-around choice for most situations | Generic 6AN 70" Stainless Steel Braided Transmission Cooler Line Kit |  |
| Best Value The sweet spot between price and what you get | Generic Stainless Steel Braided AN6 Transmission Cooler Line Kit, 52-inch |  |
| Best Budget The cheapest option that still gets the job done reliably | Psrorkeu Automatic Transmission Oil Cooler Hose Assembly for Chrysler 300, Dodge Challenger, Dodge Charger (direct-fit) |  |
| Most popular A crowd favorite that many people choose with confidence | Autoutfit AN6 15ft Transmission Cooler Line Kit with Nylon Braided Hose |  |
| Best Seller A high-volume bestseller chosen again and again | A-Premium Transmission Oil Cooler Line Assembly for Chrysler 300, Dodge Charger/Challenger (2013-2021) |  |
1. Generic 6AN 70" Stainless Steel Braided Transmission Cooler Line Kit
| Material | Stainless Steel/PTFE |
|---|---|
| Length | 70 Inches |
| Fitting size | 6AN |
| Included fittings | 90-degree adapters and transmission inserts |
This kit supplies two 70-inch stainless steel braided PTFE transmission lines with -6AN fittings plus assorted 90-degree adapters and transmission inserts to connect to a remote cooler. It is typically used to replace brittle factory hard lines or to add an auxiliary cooler for towing and spirited driving, moving fluid between the transmission and an aftermarket cooler to reduce operating temperature. The stainless braid and PTFE inner tube improve abrasion resistance and corrosion tolerance compared with rubber hose, and the included 90-degree fittings make routing easier in tight engine bays. Several buyers report the kit holds high pressure and installs cleanly when the factory fittings match -6AN sizing. Expect to source a few extra adapters on certain vehicles because the kit is marketed as universal and does not include every OEM-style quick-disconnect or ORB adapter. Quality control appears mixed in some batches, so inspect seals and threads before installation and have thread sealant or replacement fittings ready if needed.
Best for: Balanced owners who want a durable aftermarket transmission line kit to add a remote cooler or replace aging hard lines and who prioritize a mix of longevity and value.
Less Ideal for: Drivers seeking an exact fit, plug-and-play Chrysler-specific kit with OEM-style quick-disconnect fittings should consider a vehicle-specific assembly or professional hose shop instead.
- Stainless steel braid with PTFE core resists abrasion and corrosion for longer service life.
- 70-inch length covers many routing options and allows installation of a remote cooler.
- Includes 90-degree fittings and transmission inserts to simplify connections and routing.
- Holds high system pressure according to user reports, suitable for heavy use like towing.
- Universal fit means additional adapters may be required to match Chrysler-specific factory fittings.
- Some buyers reported inconsistent quality control including wrong lengths or damaged/used parts in rare cases.
Verdict: A durable, value-oriented braided 6AN 70" kit good for adding a remote cooler to Chrysler 300s, but expect to source Chrysler-specific adapters or check fitment carefully before installation.
2. Generic Stainless Steel Braided AN6 Transmission Cooler Line Kit, 52-inch
| Material | Stainless Steel and PTFE |
|---|---|
| Length | 52 Inches |
| Fitting Size | AN6 |
| Compatible Transmissions | Turbo 350, Turbo 400, Turbo 200/200R4, Powerglide, 700R4, 4L60/4L60E/4L65E, 4L80E, Ford C4/C6/AOD |
This kit supplies stainless steel braided AN6 transmission lines and fittings to connect a Chrysler 300 transmission to an external cooler or to replace worn factory lines. Installation typically involves routing the pre-bent lines from the transmission outlets to a remote cooler, installing the included 90-degree fittings and transmission inserts where required, and sealing connections with appropriate tape or thread sealant. The braided PTFE core with stainless braid offers corrosion resistance, flexibility for routing behind the engine, and pressure-holding capability for towing or higher-load driving. Buyers benefit from longer, ready-made lengths and multiple adapter fittings that reduce custom hose-building. Limitations include the universal AN6 sizing which may not match the Chrysler 300 factory fittings without additional adapters, and mixed quality reports that indicate some kits arrive with inconsistent fittings or assembly issues, so expect to inspect and possibly chase threads before installation. For owners comfortable modifying fittings or sourcing an extra adapter kit, this is a cost-effective way to add transmission cooling capacity to a Chrysler 300.
Best for: Practical optimizers who want an affordable, do-it-yourself solution to add or replace transmission cooler lines on a Chrysler 300 and are willing to source one or two extra adapters if needed.
Less Ideal for: Drivers seeking a direct-fit, factory-quality replacement without any modification or extra parts should consider vehicle-specific hose assemblies from a dealer or specialist instead.
- Stainless steel braided PTFE construction resists corrosion and holds pressure.
- Includes 90-degree fittings and transmission inserts for common routing needs.
- Long pre-made hose lengths simplify adding a remote cooler without hose-building.
- Compatible with many automatic transmissions used in conversions when paired with the right adapters.
- Kit uses universal AN6 sizing that may require additional adapters to fit Chrysler 300 factory ports.
- Quality control appears inconsistent across units with occasional damaged or mis-sized parts.
- Some buyers report threads or fittings that need cleaning or chasing before installation.
Verdict: A budget-friendly braided AN6 line kit that adds transmission cooling capacity to a Chrysler 300 if you are prepared to fit a small number of adapters and inspect parts before installing.
3. Psrorkeu Automatic Transmission Oil Cooler Hose Assembly for Chrysler 300, Dodge Challenger, Dodge Charger (direct-fit)
| Vehicle Fitment | Chrysler 300 2013-2021; Dodge Challenger 2015-2021; Dodge Charger 2013-2021 |
|---|---|
| Part Number | 624-441 / 55111280AA series |
| Quantity Needed | 1 |
| Position | Inlet and Outlet |
This Psrorkeu transmission oil cooler hose assembly is a direct-replacement inlet and outlet line made to fit Chrysler 300 (2013-2021), Dodge Challenger (2015-2021), and Dodge Charger (2013-2021). It is supplied with factory-style fittings so it bolts in without modifications, making it a straightforward DIY fix to stop leaks and restore the transmission cooling circuit. The listing notes pressure testing and quality inspections, which suggests each line is checked for leaks before shipping. In practice the part returns the system to working order quickly and avoids the confusion of sourcing hard-to-find OEM numbers. Expect a simple install with common hand tools and no need for adapters. The main limitation is that this is a single replacement line sold as one unit and it is an aftermarket part rather than a branded factory component, so long-term durability may vary compared with factory replacements. Still, for a low-cost, bolt-on repair it provides a practical way to stop fluid loss and reduce the risk of transmission overheating.
Best for: Budget-conscious owners who want a straightforward, low-cost repair to stop transmission fluid leaks and restore the cooler circuit without dealer labor.
Less Ideal for: Buyers seeking a factory-branded or long-term upgraded performance line should consider OEM replacements or premium braided options instead.
- Direct-fit design with factory-style fittings for simple bolt-on installation
- Pressure-tested and inspected to reduce the chance of shipping leaks
- Specifically listed to fit Chrysler 300, Dodge Challenger, and Dodge Charger model years covered
- Stops transmission fluid leaks to restore cooling system integrity quickly
- Aftermarket part rather than a named factory replacement so long-term durability may differ from OEM
Verdict: A budget-friendly, direct-fit transmission cooler hose assembly that makes an easy DIY repair to stop leaks and restore cooling on covered Chrysler and Dodge models.
4. Autoutfit AN6 15ft Transmission Cooler Line Kit with Nylon Braided Hose
| Material | 304 Steel, Aluminum Alloy, Nylon, Rubber |
|---|---|
| Hose length | 15 Feet |
| Fitment note | Compatible with 4L60E 4L65E Transmission |
| Fitting type | -6 AN straight and 90° hose ends |
This Autoutfit kit supplies 15 feet of -6 AN braided transmission hose plus a selection of straight and 90° aluminum hose ends and transmission/radiator fittings to build or replace cooler lines. Intended for use with 4L60E/4L65E-equipped vehicles, the hose combines a rubber inner core with 304 steel wire reinforcement and a nylon outer braid for abrasion resistance while fittings are lightweight aluminum. In practice the kit is useful for custom routing and repairs where factory steel lines are corroded or too rigid, and the long length lets you trim to fit a Chrysler 300 with a 4L60E conversion or swap that accepts AN6 fittings. Installers should prepare for assembly: fittings require proper seating and some users add vice support or extra shop fittings for easier thread engagement. A few reviewers report the supplied radiator fitting does not thread as deeply on some factory radiators, so you may need additional adapters for a flush, OEM-style connection. The kit provides flexibility and modern hose construction but may need small parts or adapters to match Chrysler radiator ports exactly.
Best for: Convenience-driven buyers who want a ready-made hose-and-fitting kit to rebuild or custom-route transmission cooler lines quickly without fabricating parts from scratch.
Less Ideal for: Owners seeking a direct factory-style replacement that threads into Chrysler radiator ports without modification should consider a vehicle-specific OEM-style line or a kit that explicitly lists Chrysler 300 fitment and matching radiator adapters.
- Long 15 ft supply lets you cut custom lengths and tidy routing for engine bays
- Nylon-braided hose with steel wire reinforcement resists abrasion and holds pressure better than plain rubber
- Includes a mix of straight and 90° AN6 hose ends for flexible routing options
- Aluminum fittings are lightweight and corrosion resistant compared with steel alternatives
- Some radiator fittings in the kit have limited thread engagement on certain factory radiators, possibly requiring extra adapters
- Assembly needs care and hand strength; fitting installation can be difficult without a vise or proper tools
Verdict: A flexible, long AN6 braided hose kit that simplifies building transmission cooler lines but may require extra radiator adapters for a flush Chrysler 300 installation.
5. A-Premium Transmission Oil Cooler Line Assembly for Chrysler 300, Dodge Charger/Challenger (2013-2021)
| Compatible Vehicles | Chrysler 300 2013-2021; Dodge Charger 2013-2021; Challenger 2015-2021 |
|---|---|
| Included Parts | Inlet and outlet transmission oil cooler lines |
| Manufacturer Part Number | APOCL553 |
| OEM Reference Numbers | 5801755, 55111280AD, 624441, 624-441 |
This A-Premium transmission oil cooler line assembly replaces the inlet and outlet lines on compatible Chrysler 300, Dodge Charger and Challenger models and is intended to restore proper fluid routing to the transmission cooler. It is typically used when original lines develop leaks, cracks, or corrosion and when a direct replacement is needed during routine cooling system or transmission work. The lines are described as corrosion-resistant and engineered to transfer oil efficiently to the cooler, which helps maintain transmission temperature under normal driving and towing conditions. Practical benefits include factory-style fitment references that match common OEM part numbers and a one-year unlimited-mileage guarantee for peace of mind. Limitations to consider are that fitment is specific to the listed model years and engine configurations so verification before purchase is required, and while the listing emphasizes durable construction it does not provide detailed material or pressure ratings for heavy-duty or extreme-performance use.
Best for: Risk-averse mainstream buyers who prioritize restoring factory-style cooling performance and minimizing future leaks on Chrysler 300s and similarly equipped Chargers or Challengers.
Less Ideal for: Drivers seeking heavy-duty or aftermarket performance upgrades for extreme towing or racing should consider purpose-built high-pressure lines instead.
- Direct replacement lines referenced to common OEM part numbers for easier fit confirmation
- Corrosion-resistant construction aimed at reducing leaks and extending service life
- Covers both inlet and outlet lines so both sides of the cooler circuit can be renewed at once
- One-year unlimited-mileage guarantee provides added assurance for cautious buyers
- Compatibility is limited to specific model years and must be confirmed before ordering
- Manufacturer details do not list material composition or operating pressure specifications
Verdict: A direct-fit replacement cooler line assembly that restores factory-style transmission cooling and reduces leak risk for supported Chrysler 300, Charger, and Challenger model years.
Choosing the Right Chrysler 300 Transmission Cooler Line: Key Factors to Consider
Fitment and Vehicle-Specific Compatibility
Correct fitment matters because a cooler line that does not match the Chrysler 300's routing will be difficult to install, may rub against chassis components, and can lead to premature wear or failure.
Look for parts that reference exact model years, transmission type, and mounting points. A precise fit reduces the need for bending or modification during installation, which preserves line integrity and sealing surfaces.
Material and Corrosion Resistance
Materials influence how well a cooler line withstands road salt, moisture, and heat cycles. Hard lines are usually steel or aluminum with corrosion-resistant coatings, while hoses use synthetic rubber or reinforced polymer.
Choosing corrosion-resistant materials and protective coatings lengthens service life and lowers the chance of leaks developing from rust or material breakdown.
Sealing Method and Connection Quality
The type of fittings and seals determine how reliably the line holds pressure and resists fluid seepage. Common connection styles include flare fittings, crimped hose ends, and threaded adapters.
High-quality crimps, properly sized flares, and precision-machined mating surfaces reduce leak risk. Consider whether replacement includes new seals or O-rings, as reusing old seals can compromise the repair.
Routing and Bend Retention
How the line is routed affects clearance from heat sources and moving parts. Lines with good bend retention keep their shape after installation and resist kinking during vehicle movement.
A line that retains its bends and uses appropriate mounting clips will avoid contact with hot exhaust components, reducing thermal stress on the fluid and the line itself.
Durability Under Heat and Vibration
Transmission cooler lines operate near the engine and must handle continuous thermal cycling and drivetrain vibration. Hoses and fittings should be rated for high-temperature fluid, and hard lines should resist metal fatigue.
Reinforcement layers, braided coverings, or protective sleeves improve resistance to abrasion and vibration-induced fatigue, which helps prevent leaks and ruptures over time.
Installation Hardware and Support
Availability of correct fittings, clips, and mounting hardware simplifies installation and reduces install-time mistakes. Some kits include adapters and replacement clamps designed for the Chrysler 300's layout.
Clear instructions and accessible technical support can be valuable if questions arise during installation, especially for first-time DIYers.
How We Chose the Best Chrysler 300 Transmission Cooler Line
We focused on factors that directly affect long-term performance and installation success for Chrysler 300 transmission cooler lines. Primary evaluation criteria included fitment precision to the vehicle chassis and transmission connections, material durability such as corrosion resistance and abrasion protection, sealing and connection design to minimize leaks, and ease of installation including supplied fittings and mounting hardware. We also considered the line routing and bend retention to ensure the part maintains shape under heat and vibration, plus warranty coverage and manufacturer technical documentation. Exclusions: we excluded products that lacked clear fitment validation for the Chrysler 300, components without specified materials or connection types, and items with inconsistent user feedback about leaks or premature failure. The chosen items met these filters and scored well on the measurable dimensions that matter for transmission cooling reliability.
Our full evaluation process is outlined in our review methodology.
FAQ
How do I know if my Chrysler 300 transmission cooler line is leaking?
Common signs include visible fluid under the vehicle near the transmission area, a drop in transmission fluid level, or a strong smell of burning transmission fluid. You may also notice transmission slipping or erratic shifting if fluid loss becomes significant. Inspect lines and connections visually, and check fluid level regularly when you suspect a leak.
Can I replace a transmission cooler line myself?
Many owners can replace a cooler line with basic mechanical skills and the right tools, particularly if the new line is a direct-fit part. Ensure you have proper fittings, clamps, and an understanding of the vehicle's routing. Take precautions to avoid contamination of the transmission system and follow torque specs for fittings. If routing or connection issues arise, professional help is advisable.
Should I choose a hard line or a hose for the cooler line?
Hard lines offer ruggedness and better resistance to abrasion and pressure, while hoses can provide flexibility where tight routing or engine movement is a concern. The best choice depends on the Chrysler 300's original design and the specific routing needs. Prioritize materials and connections that minimize leak risk and suit the vehicle's layout.
What causes transmission cooler line leaks besides corrosion?
Leaks can stem from loose or damaged fittings, degraded seals or O-rings, mechanical abrasion from contact with other components, and metal fatigue from repeated vibration. Incorrect installation or overtightening can also damage fittings. Regular inspection and correct routing help reduce these risks.
Do replacement cooler lines come with fittings and seals included?
Some replacement lines and kits include new fittings, clamps, and seals, while others supply only the line. Choosing a kit that provides the necessary hardware reduces the chance of mixing incompatible components and simplifies installation. Verify the contents before starting the job to ensure you have all required parts.
Conclusion
When replacing a Chrysler 300 transmission cooler line, prioritize correct fitment, durable materials, and reliable connection methods. These factors have the biggest impact on leak prevention and long-term performance. Understand the routing and mounting needs, and prefer parts that include appropriate hardware or clear installation guidance. Balancing flexibility, corrosion resistance, and strong sealing will help you pick a solution that minimizes future service needs.If you are unsure about routing or sealing details, consult a technician who can confirm compatibility and installation technique to avoid common pitfalls such as abrasion or improper fittings.
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