1999 Ford Ranger decided it was time to make a milkshake

[VersatileGuy]

4r44e Transmission. Milkshake indicates transmission and coolant has started to mix. Might have just happened as what I noticed is that the harsh shifting of the transmission(from the lack of fluid or different type as I used regular Mercon instead of Merc V substitute) actually became smoother.

So, what's the long term viability of the transmission now? I had just tried a valve body swap to restore drive, which it did.

 

[BrendanC]

4r44e Transmission. Milkshake indicates transmission and coolant has started to mix. Might have just happened as what I noticed is that the harsh shifting of the transmission(from the lack of fluid or different type as I used regular Mercon instead of Merc V substitute) actually became smoother.

So, what's the long term viability of the transmission now? I had just tried a valve body swap to restore drive, which it did.

keep doing drain and fills on it

 

[Lubener]

If there's any chance of saving it, get all the contaminated fluid out asap. The coolant contamination will ruin band and clutch linings.

 

[DuckRyder]

^^^

Yup, and do not get it hot until the water is out. and whatever (the cooler presumably) is letting it mix is fixed.

 

[Kira]

At what mileage did this happen?
Condition of coolant?
Are radiators best changed at ~25 years of age?

 

[VersatileGuy]

At what mileage did this happen?
Condition of coolant?
Are radiators best changed at ~25 years of age?

This thing sat for a while with old coolant. Was bought used maybe 6-8 years ago. Mileage was at 265k, but this was a near scrapyard truck due to the more common blown valve body gasket. Bought an Ebay reman valve body, but I might return it because it drove forward in neutral and I don't have reverse(there's also the reverse servo O-rings, because the servo just fully fell out when dropping the valve body.

I just did the valve body swap about two weeks ago when the transmission was not full of coolant. Black and nasty smelling stuff came out, so it wasn't leaking at that time.

Probably should have change the radiator years ago. Well, I might was well use some of the Amsoil mixed fluid from the fluid of a Toyota Matrix for this "cleanse".

 

[MasterSolenoid]

I can see the coolant mixing with the oil.
But how can the transmission fluid and coolant mix?

 

[VersatileGuy]

^^^

Yup, and do not get it hot until the water is out. and whatever (the cooler presumably) is letting it mix is fixed.

I'm looking at junkyard radiators at the moment. Since the system is tainted, I'm going to hold off on a new one until later, because the tranny might die earlier than the life of a new rad.

I can see the coolant mixing with the oil.
But how can the transmission fluid and coolant mix?

Radiator design and failure. I checked the dipstick of the trans and saw the milkiness. Then I checked the coolant reservoir. Whitish also. Neither looked that way just a week ago.

Might be good rule of thumb to swap out a rad when buying any used car with such a design.

 

[K-Man]

I can see the coolant mixing with the oil.
But how can the transmission fluid and coolant mix?

The factory radiators have lots of plastic. The plastic cracks at high mileage, causing leaks and catastrophic fluid loss. On my Ranger I replaced the factory radiator at 150,000 miles for an aftermarket all-aluminum radiator last year to avoid that problem, just as I replaced the plastic factory thermostat housing for an aftermarket cast-aluminum one.

Newer Nissans are notorious for the same radiator design problem that puts coolant in the ATF. That failure occurs much earlier, before 100,000 miles in many cases.

 

[Greenbeforeblue]

Aren't the transmission and radiator two separate circuits that don't have anything to do with the other?

 

[bdcardinal]

I can see the coolant mixing with the oil.
But how can the transmission fluid and coolant mix?

Transmission cooler that is integral to the radiator.

 

[LouC]

Yep the standard auto trans coolers are inside the radiator, so if leaks antifreeze will get into your trans fluid. The only exception to this I am aware of is my 2007 Grand Cherokee this has the 5.7 V8 with the hydraulic fan, the trans cooler is actually the top half of the AC condenser, there is no in-rad cooler on these.
On my '98 Grand Cherokee there was an in-rad cooler and I added an auxiliary cooler to it about 10 years ago.
Antifreeze mixing with either transmission fluid or motor oil is very bad.

 

[Nukeman7]

I can see the coolant mixing with the oil.
But how can the transmission fluid and coolant mix?

Aren't the transmission and radiator two separate circuits that don't have anything to do with the other?

 

[Chris142]

I can see the coolant mixing with the oil.
But how can the transmission fluid and coolant mix?

Transmission cooler in the radiator has failed.

 

[Chris142]

99% of the time when an automatic transmission gets water in it it's doomed shortly after.

 

[BrendanC]

my 4l80e went almost 100k miles after being flooded in hurricane harvey (i bought a flooded truck to preform a 4x4 swap on my pickup) the truck had 90k on it when bought. i dropped the pan, brake cleaned everything i could see then filled it up until it started leaking out of the vent line and let it sit for a little while. i drained this and refilled again with fresh fluid and started the truck to let it run for 15 minutes cycling through the gears on jack stands. i drained that again and refilled. after that it got animal fluid/filter change and finally just wore out.

 

[VersatileGuy]

Alright, so I cracked open the petcock. Thankfully, it seems the radiator coolant is mostly clear and has some bubbles. There is just a hint of a tranny smell, indicative of the totally wasted, possibly original fluid(or just very long no-change) of the transmission. I need to take the drain pan out into the light to see how bad the cooling system mix is, as this is all under the shadows of the engine on a cloudy day. The tranny mix, well, revealed itself very clearly on the dipstick.

But of course, these things are small problems compared to the "faux flare" on the tranmission cooler lines being yet another STUCK together union with the radiator ends. I will need a 24-28 mm wrench to pair with the 16mm I have, and probably heat to take it off IF it can loosen up that way. Or destructively sawzall the rad where the coolers attach. Then I have to be super careful in not twisting the cooler lines.

 

[VersatileGuy]

Well, the lines didn't need to be cut thanks to a medium sized pipe wrench. Pipe wrenches might be favorite tool, because the never lose grip and give so much more torquing. Gave me the grip I needed and just enough space to accommodate one.

 

[Kira]

Newer Nissans are notorious for the same radiator design problem that puts coolant in the ATF. That failure occurs much earlier, before 100,000 miles in many cases.

Newer than the OP's 1999 Ranger, yes.
Nissan owners have posted that the weak transmission cooling loop problems were fixed by 2007 or 2008.
There were two Frontiers in my circle. One friend bought a 2007, the other, a 2017.
I gotta admit I've fallen way behind on my Nissan board readding.

 

[SwampSurvivor]

99% of the time when an automatic transmission gets water in it it's doomed shortly after.

To be fair, those transmissions are pretty weak and didn't last long at all. It might fail soon just because that was when its time was up anyway.