Triax ATF 689 Full Synthetic ZF 6HP/8HP/9HP ATF, 5 Quart

If you own a BMW, Audi, Jaguar or Land Rover with the ZF 6HP six-speed, or a Jeep, RAM or late-model European car with the ZF 8HP or 9HP, you have probably found out that these gearboxes do not take generic multi-vehicle ATF. Triax ATF 689 is a 100 percent synthetic fluid made for that family, and one five-quart jug covers a typical pan service. Owners usually go looking for it when the car starts showing a light-throttle shudder, a harsh 1-2 or 2-3 shift, a slow engagement into Drive, or when a leak repair means the fluid has to come out anyway.

What the fluid does in a ZF 6HP, 8HP or 9HP

In these units the fluid is a hydraulic control medium first and a lubricant second. The mechatronic unit meters line and clutch apply pressure through small solenoid-controlled valves, and the shift software expects a fluid with a specific friction curve and viscosity. On the 6HP the converter clutch is also run in controlled slip, so friction stability directly decides whether the car shudders at cruise. When the fluid oxidizes or the friction modifiers are used up, apply times drift away from what the adaptations learned, and that is felt as flare, bump or shudder. ZF's own data sheet for LifeguardFluid 6 warns that using oils other than the approved type can cause poor shifting or transmission failure, which is why a dedicated low-viscosity ZF-type fluid matters here.

To be clear about what this jug is: Triax is an aftermarket fluid, not a ZF-branded product. Triax markets ATF 689 as a replacement for ZF LifeguardFluid 6 (S671 090 255), LifeguardFluid 8 (S671 090 312), LifeguardFluid 9 (S671 090 399) and Mopar 8- and 9-speed ATF. If you want the factory fluid itself, we also stock ZF LifeguardFluid 6 in a 6 liter pack.

Symptoms that point to tired or wrong fluid

• Shudder or a rumble-strip feel between roughly 25 and 50 mph at light throttle
• Harsh or delayed upshifts, especially once the transmission is fully warm
• A thump or delay engaging Drive or Reverse from Park
• Fluid that is dark brown or smells burnt on the dipstick rag or at the fill plug
• Gear ratio or shift error codes such as P0729-P0734 appearing after a service with the wrong fluid or a low level

How to confirm the fluid is the problem

Check level and condition before you blame hardware. Pull the fill plug at the correct temperature and look at what comes out; a fresh, red-amber fluid at the right level with harsh shifts points elsewhere, usually the valve body or solenoids. Our ZF6HP fluid type and capacity guide walks through which variant takes which spec, and the BMW 3 Series 6HP fluid change guide covers the full level procedure. ZF advises against changing fluid on a unit that already smells burnt or has large chips in the pan, because the problem is already mechanical.

Fitment

The listing covers ZF 6HP units (6HP19, 6HP21, 6HP26, 6HP28 and related) in BMW, Audi, Jaguar and Land Rover; the 8HP45 and 8HP70 in BMW, Audi, Jaguar, Land Rover and the Chrysler 845RE/850RE in Jeep Grand Cherokee, Wrangler and RAM 1500; and the 9HP48 (948TE) in the Jeep Cherokee, Renegade and Chrysler 200. ZF does not use one fluid for every 6HP: a few versions, including some 6HP19X applications, are specified for LifeguardFluid 8 rather than 6. Check the tag on your transmission case or the owner documentation, and if you are unsure send us your year and VIN before ordering. Browse everything for these units on our ZF 6HP parts page.

Install notes

• Quantity: a pan drop on a 6HP or 8HP takes most of one jug; a full exchange or a dry unit after an overhaul needs two or more.
• Fill through the side fill plug with the car level, engine running, until fluid just starts to run out.
• Set the level hot but not too hot. ZF's BMW 6HP19/6HP21 procedure starts around 30-35 C and warns that a level set above about 50 C will read low once cooled.
• On 6HP units with the plastic pan, the filter is built into the pan, so replace the pan with the 6HP26 pan, filter and gasket kit and torque the bolts crosswise to spec.
• If fluid is weeping at the connector, fix the mechatronic sleeve and connector seals while the pan is off.

ZF calls the fill lifetime oil but recommends a change around 150,000 km, and sooner under towing, heat or unknown history. Ships fast from the USA.

Is Triax ATF 689 the same as ZF LifeguardFluid 6?

No. It is an aftermarket full synthetic fluid that Triax markets as a replacement for LifeguardFluid 6, 8 and 9 and Mopar 8- and 9-speed ATF. If you want the ZF-branded fluid, we also carry LifeguardFluid 6 in a 6 liter pack.

How many jugs do I need for a 6HP pan service?

A pan drop with a new pan and filter usually uses most of one 5 quart jug. A fully dry 6HP19 or 6HP21 holds about 9 liters, so an overhaul or a full exchange needs two or more.

Can I use it in a Jeep Grand Cherokee or RAM 1500 8-speed?

The listing covers the Chrysler 845RE/850RE (ZF 8HP) in the Grand Cherokee, Wrangler and RAM 1500, plus the 9HP48 948TE in the Cherokee, Renegade and 200. Confirm your transmission code first.

Will new fluid fix my 6HP shudder?

It can if the shudder comes from worn-out fluid, and that is the cheapest first step. If shudder returns quickly with fresh fluid at the correct level, the converter clutch circuit, valve body or converter itself needs diagnosis.

At what temperature do I check the level?

With the engine running at a fluid temperature in ZF's window. For BMW 6HP19 and 6HP21 that means starting the check around 30-35 C; setting the level above about 50 C leaves it low.

• ZF6HP Fluid Type and Capacity: The Right Spec for Every Variant
• ZF6HP BMW 3 Series Fluid Change: Type, Capacity and Cost
• ZF6HP BMW 5 Series Fluid Change: Type, Capacity and Cost
• ZF6HP Jaguar Fluid Change: Type, Capacity and Cost
• ZF6HP Fluid Leak: The Common Spots and How to Fix Each One