2025 Jeep Gladiator: Transmission Fluid & Service

Quick answer

• Transmission model: ZF 8HP75 (8-speed automatic)
• OEM fluid specification: Mopar ZF 8&9 Speed ATF (or equivalent meeting FCA US MS-90030-A5 specification)
• Drain & fill capacity: Approximately 5.5 - 6.0 quarts (verify with dipstick or service manual)
• Full overhaul capacity: 9.0 quarts
• Filter OEM part number: Integrated into the transmission pan; part number 68521350AA (verify with dealer)
• Recommended service interval: 60,000 miles (normal duty) or 30,000 miles (severe duty)

Fluid type explained

The 2025 Jeep Gladiator is equipped with the robust and efficient ZF 8HP75 8-speed automatic transmission. This advanced transmission requires a very specific fluid to ensure proper operation, smooth shifting, and long-term durability. The required fluid is Mopar ZF 8&9 Speed ATF, which must meet the stringent FCA US MS-90030-A5 specification.

Using a fluid that is not approved to this specification can lead to a host of problems, including rough shifting, transmission overheating, and premature wear of internal components like the clutch packs and torque converter. While some aftermarket fluids claim to be "compatible," it is always safest to use the genuine Mopar fluid or a licensed equivalent that explicitly states it meets the MS-90030-A5 spec. Using incorrect fluid can even void your vehicle's warranty.

Service procedure

When it comes to servicing your Gladiator's transmission, you have two primary options: a drain and fill or a full fluid exchange.

• Drain and Fill: This is the most common and straightforward method. It involves draining the fluid from the transmission pan, replacing the integrated filter/pan assembly, and refilling the transmission with fresh fluid. This process typically replaces about 5.5 to 6.0 quarts of the total fluid, leaving some of the old fluid in the torque converter and cooler lines. For most normally-driven vehicles, this is a perfectly acceptable and effective service.

• Full Fluid Exchange: A full exchange, often called a "flush," uses a specialized machine to pump out all of the old fluid while simultaneously pumping in new fluid. This method replaces nearly 100% of the old, degraded fluid. A full exchange is recommended for vehicles that have been subjected to severe use, have gone well beyond the recommended service interval, or are exhibiting shifting problems that might be related to fluid degradation. It's a more expensive and time-consuming procedure, but it provides the most complete fluid replacement.

Crucially, the ZF 8HP75 transmission features a plastic pan with an integrated, non-serviceable filter. During any fluid service, this entire pan and filter assembly must be replaced as a single unit (OEM part #68521350AA). Always verify the part number with your dealer or a trusted parts supplier before purchasing.

Service interval

Jeep provides two different service intervals based on how the vehicle is used. It is critical to be honest about your driving habits to ensure the longevity of your transmission.

• Normal Duty (60,000 miles): This interval applies to most drivers who use their Gladiator for daily commuting, highway driving, and occasional light-duty work with infrequent exposure to extreme conditions.

• Severe Duty (30,000 miles): Many Gladiator owners will fall into the severe duty category without realizing it. This schedule is recommended if you frequently:

  • Tow trailers or haul heavy loads
  • Engage in off-road driving
  • Operate in dusty, sandy, or muddy conditions
  • Make frequent short trips in cold weather
  • Drive in stop-and-go city traffic in hot weather

Following the severe duty schedule is a wise investment in the health of your transmission if your truck is used as intended for work and play.

Common transmission problems

The ZF 8-speed is a well-regarded transmission known for its reliability. However, no component is perfect. Some issues that can arise, particularly as the vehicle ages or if service is neglected, include:

• Rough or Delayed Shifting: Often the first sign of degraded fluid or low fluid levels. A fluid and filter service is the first logical step in diagnosing this issue.
• Solenoid Failure: The transmission's mechatronic unit (a combination of the valve body and control module) contains solenoids that control fluid flow to enable shifting. Over time, these can fail, leading to stuck gears or harsh shifts. Clean fluid is essential for solenoid longevity.
• Software and Electronic Issues: Modern transmissions are heavily reliant on software. Occasionally, shifting issues can be traced back to the Transmission Control Module (TCM) and may be resolved with a software update from the dealer.
• Leaks: While not a common failure point, leaks can develop from the pan gasket or cooler line fittings. Any fluid leak should be addressed immediately to prevent low fluid levels and catastrophic damage.

Regular inspection and timely fluid services are the best defense against these potential problems.

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