CriticalCommonTransmission

Ford Falcon: Radiator's built-in transmission cooler lets coolant into the gearbox - 'the milkshake' (BA and BF before BF II)

Radiator's built-in transmission cooler lets coolant into the gearbox - 'the milkshake' (BA and BF before BF II) is a common transmission fault on the Ford Falcon on the 2002–2006 cars, and we rate it critical. Putting it right costs $3,500 to $8,000 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 36 documented faults on the Ford Falcon.

Vehicle: Ford Falcon
Years: 2002–2006
Fuel: petrol
Gearbox: auto
System: Transmission

This page covers the Ford Falcon as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Ford Falcon faults36 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the Radiator yet. We would rather show none than show a picture of a different part.

What goes wrong

On BA and early BF automatics the transmission fluid is cooled by a heat exchanger built into the bottom tank of the radiator. When the wall between the two circuits corrodes, pressurised engine coolant is forced into the transmission and transmission fluid escapes into the coolant. The result is a pink-brown frothy mixture - hence the nickname - that destroys the clutch packs and valve body, often within a few hundred kilometres. It also leaves contamination sitting in the cooler lines, so a rebuilt gearbox is ruined again if the radiator and lines are not replaced and flushed at the same time. Ford moved to an external transmission cooler from BF II onwards, which is why the later cars do not do it. There was never a recall, so the whole bill falls on the owner. This is a different failure from the radiator simply cracking and losing coolant: here the two fluids mix internally and the gearbox is the thing that dies.

What you would notice

Pink, brown or frothy 'strawberry milkshake' fluid on the transmission dipstick
Oily film or brown scum floating in the coolant expansion tank
Coolant level dropping with no external leak anywhere
Harsh, slipping or flaring gearchanges
Transmission warning or the car dropping into limp mode

How to check it

Where to look. Bottom tank of the radiator at the front of the engine bay where the two transmission cooler pipes enter; the evidence shows on the transmission dipstick and in the coolant expansion tank.

This is the single most expensive thing that goes wrong with a BA or early BF, and you can check it in two minutes before you even drive the car. With the engine cold, look into the coolant expansion tank with your phone torch: clean coloured coolant is fine, but an oily brown film, scum around the neck or a milkshake colour is not. Then pull the transmission dipstick, which sits at the back of the engine on the passenger side, and wipe it on a white tissue: healthy fluid is clear red and smells sharp, contaminated fluid is pink-brown, cloudy or frothy. Look where the two gearbox cooler pipes run into the bottom of the radiator for weeping or crusty pink residue. On the test drive, note any flare between gears or a change that arrives late and then thumps in. Ask whether an external transmission cooler has been fitted and the radiator one bypassed, and ask for the invoice, because that is the permanent fix and it makes the car a much safer buy. Ask when the radiator was last replaced and when the transmission fluid and filter were last changed.

Parts involved: Radiator.

What it costs to put right

$3,500 to $8,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Has an external transmission cooler been fitted and the radiator one bypassed?”
“Has the radiator ever been replaced, and when?”
“When was the transmission fluid and filter last changed?”
“Has the gearbox ever been rebuilt or replaced?”

Now check the Ford Falcon you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

CarsGuide Q&A 'Ford Falcon: Transmission coolant problem' (BA Falcon leaking coolant)
CarsGuide Q&A 'Ford Falcon: External oil cooler' (BF transmission cooler)
MotoringBox 'Fit a Transmission Cooler and Avoid a Milkshake!'
Whirlpool Forums 'Best way to prevent XR6 Milkshake from occurring'

Ford Falcon buyer questions

Is radiator's built-in transmission cooler lets coolant into the gearbox - 'the milkshake' (ba and bf before bf ii) serious on a Ford Falcon?

We rate it critical and common on the Ford Falcon. On BA and early BF automatics the transmission fluid is cooled by a heat exchanger built into the bottom tank of the radiator. When the wall between the two circuits corrodes, pressurised engine coolant is forced into the transmission and transmission fluid escapes into the coolant. The result is a pink-brown frothy mixture - hence the nickname - that destroys the clutch packs and valve body, often within a few hundred kilometres. It also leaves contamination sitting in the cooler lines, so a rebuilt gearbox is ruined again if the radiator and lines are not replaced and flushed at the same time. Ford moved to an external transmission cooler from BF II onwards, which is why the later cars do not do it. There was never a recall, so the whole bill falls on the owner. This is a different failure from the radiator simply cracking and losing coolant: here the two fluids mix internally and the gearbox is the thing that dies.

How much does it cost to fix on a Ford Falcon?

$3,500 to $8,000 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Ford Falcon years are affected?

Our research records this fault on the 2002–2006 Ford Falcon. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.