Boiling transmission!?

[45-70]

So... I was on my way to one of my hunting sites for moose hunting (in Sweden). A quad on the bed and a small caravan on towe. A load, sure, but far from max. Three houers into the drive there was a road block, so I had to sit on idle for about half an houer. Two miles after that the truck just stopped pulling.
I stoped and all the transmission fluid had just spewed out on the road. Empty tranny.
I thougt I had it blown. Got it towed to a shop the day after. There they filled her up with fluid again and run her with load to try finding the leak. And... there are no leak!!
The mechanics theory is I overheated the transmission, and the fluid boiled out. Out the front where it connects with the engine.
I have today run the whole lot three houers up to the next hunting site. No problems. I did drive more careful. About 50mph max, and only put it on drive (no overdrive).

So, is this really what is expected from this machinery?? Or do I have a problem causing it? What in that case?
This feels very uncomfortable, when this is the use I got the truck for.

Anyone have an idea?

1988 Ford Ranger 4x4 STX, 2,9l, electric t-case. (Don't know what tranny)

 

[Roert42]

I am not an expert on auto transmissions, and I'm sure someone else will that is will chime in.


That being said, if you do have an issue with overheating your transmission you could always add an aftermarket transmission cooler to help.

You could also upgrade the transmission with a shift kit, may not help cooling, but would help with overall performance. @lil_Blue_Ford installed one in his A4OD recently and seem very happy.

 

[RonD]

Yes, something was wrong for it to do that, I know DUH

Transmission has a Vent at the top rear that connects to a metal hose that runs forward and loops up the bellhousing then down and ends near the transmissions wiring connector on drivers side
If it was an overheating issue that's most likely where the fluid came out

You can see the metal tube in this picture: https://www.therangerstation.com/tech_library/images/4R55E.jpg

The reason for the loop up and down is so any fluid that come out, which shouldn't be be much, would run back down and back in to transmission

Most of the heat generated in an automatic is from the torque converter, yours may no longer be "locking up" at higher speeds, and this slipping generates alot of heat
So see if you can feel it being "locked" at higher speed, i.e. give it a little gas and see if engine RPMs go up before speed increases, that means its not "locked"

Generally torque converters will "lock up" above 40MPH automatically, your 1988 A4LD transmission has a solenoid(TCC) that should lock it up sooner when just cruising above or below 40MPH

 

[55trucker]

When this situation took place & you found yourself on the side of the road you must've seen where under the vehicle *all* of the fluid was appearing from. Rear of the trans, alongside the trans, the coolant lines AT the trans housing, front of the vehicle (coolant lines into the rad cooler), what did you see?

 

[45-70]

When this situation took place & you found yourself on the side of the road you must've seen where under the vehicle *all* of the fluid was appearing from. Rear of the trans, alongside the trans, the coolant lines AT the trans housing, front of the vehicle (coolant lines into the rad cooler), what did you see?

Couldn't see any obvious spot where it came out. Crawled under with a flash light, yes, ofcourse.
Semed to me it came out top front somewhare where you cant reach. Mechanics said it came out from the thing conecting it to the engine (english is not my primary language). "Bellhousing"?
RonD makes it clear to me. The vent tube must be broken on my truck, didn't se it run down on the side like on the pic.

Automatics are not very comon here, so I'm a bit wobbly on the feel for them. But as RonD sais, I might have a problem with the lockup. It "flows" between gears alot. With a gear locked I just have to give it slight gas and it will rev up an "hover" between gears for a long time. It does however lock up.

 

[45-70]

I am not an expert on auto transmissions, and I'm sure someone else will that is will chime in.


That being said, if you do have an issue with overheating your transmission you could always add an aftermarket transmission cooler to help.

You could also upgrade the transmission with a shift kit, may not help cooling, but would help with overall performance. @lil_Blue_Ford installed one in his A4OD recently and seem very happy.

What is that shift kit? Will it help with the lockups? Spare parts are sparse over here. Accessories even more so... truck is old and used so I won't put down big bucks on it

 

[RobbieD]

Glad to hear that it wasn't a serious failure.

You have an A4LD automatic, and I forgot about them "puking", which they can do when they get hot.

If your truck does not have an an auxiliary transmission fluid cooler, you really should add one.

 

[Angie]

years back we bought a 94 explorer to replace another 93 explorer. (actual plan was to swap parts out of the 94 into the 93) but 94 was in better shape... long story short....

we bought it for 400 dollars as the lady said the trans was blown.... while looking at it I placed it in gear and it wanted to go... however I pulled dip stick and it was dry... we bought it.. i trailered it home, added 4 liters of trans fluid and it drove perfect with under 160K KMS.... or about 100 Miles... Angie drove it around town for years till she fell in love with a Tahoe, and was time to rid of the expo, so i pulled the low mileage motor and scraped the rest.

this thing was a sweet ride, one day it did exactly that on a hot day... spewed trans fluid everywhere... we just refilled it and always kept 2 liters of oil in the rig for (just in case)... only happened once and didn't seem to damage anything.

 

[Dirtman]

If the transmission reaches the point where it boiled over and spewed transmission fluid you should change the fluid ASAP not just top if off. That fluid is no longer good if it got that hot. Once it gets about 240 degrees it burns and looses all ability to allow the clutches and bands to function properly.

And if you're towing with it as said, you need the biggest auxiliary cooler you can fit. The oem cooler is not big enough for normal driving let alone towing off-road.

 

[55trucker]

Couldn't see any obvious spot where it came out. Crawled under with a flash light, yes, ofcourse.
Semed to me it came out top front somewhare where you cant reach. Mechanics said it came out from the thing conecting it to the engine (english is not my primary language). "Bellhousing"?
RonD makes it clear to me. The vent tube must be broken on my truck, didn't se it run down on the side like on the pic.

If we take the mechanics word as accurate that would suggest that the fluid was forced past the front seal inside the torque converter housing or the pump housing gasket, the breather is located top center at the rear of the main trans casing just in front of the mounting flange for the tailshaft. it wouldn't necessary to dump *all* of the fluid to lose drive, a loss of just over 2 litres will affect the band & clutch pressure application causing a serious slip issue.

 

[Dirtman]

The vent tube must be broken on my truck, didn't se it run down on the side like on the pic.

Not all of them have that tube. Some just have a little wiggly metal cap on the vent fitting.

 

[Roert42]

What is that shift kit? Will it help with the lockups? Spare parts are sparse over here. Accessories even more so... truck is old and used so I won't put down big bucks on it

A4LD mods (and 4R44/4R55/5R55)

So I wasn’t exactly sure what to title this, but here’s where I’m at. I was surfing around on the web, think it was on a rainy day, and only like a month ago. Came across a thread or write up somewhere about the A4LD and it’s descendents the 4r44/4R55/5R55. Suggested the usual stuff, bigger...

www.therangerstation.com

Check out this post for info about the shift kit. It will help give a more firm shift, and increase the efficiency and longevity of the transmission.

 

[lil_Blue_Ford]

Ok, so I’ll chime in here a bit. If you’re hauling or towing, you should always run in D or Drive. Not OD/Overdrive. Helps keep the transmission happier.

A4LD automatics (what is most likely in your truck) don’t like heat at all. If it’s working fine now, then you may have got lucky. My 2000 Ranger with the 5R55 (descendent of the A4LD) puked fluid over a year ago. Filling it back up didn’t help, it was slipping worse and worse the more I drove it. Made it home, but didn’t try to go anywhere else with it and started moving forward with other plans for the truck.

Don’t know what all you can source for parts over there. Also don’t know if the trucks are set up exactly like ours or not. But I’ll run through a couple things here.

Radiator: use the one for a 90-92 4.0 with an auto. You will have to use the lower hose for that truck too. It’s a thicker radiator so better cooling capacity and it has a cooler for the transmission. Wouldn’t hurt to throw in a 180* F thermostat while it’s apart unless it’s usually really cold where you are.

Auxiliary cooler: found in front of the radiator, seems like at least around where I live pretty much all of them had this. It’s a little small so I have added a second factory sized one from a junkyard on the other side in the front. Or you can go aftermarket. But basically adding extra cooling.

Transmission: a shift kit can make a huge difference. By reducing the slop between shifts and reducing Leakage past valves you can help the transmission to run cooler and better. At minimum I would recommend the Transgo shift kit, new boost valve and the O-ring end plug kit. That’s all valve body work and you just have to pull the pan on the transmission to get to it. Also, it’s a good idea to periodically adjust the transmission bands. I have heard between 20 and 50,000 miles

 

[tomw]

There was a problem when the fluid got hot... and the viscosity lowered.... and there was a bit too much clearance at the torque converter hub to its bushing. More fluid escaped out the sides of the bushing, flooding the return port where fluid could flow back to the pan. Some of the holes were not drilled in alignment, so there was a slight restriction in the return flow path. It only happened occasionally on few transmissions that were in unusually hot condition.
Solutions are to 1) add an external fluid cooler in front of the radiator/condenser, in series with the embedded radiator cooler, or 2) remove the trans, remove the pump assembly, and re-work the return port on the front of the bushing (behind the seal) that flows to the pan, enlarging and aligning as needed. 3) ignore it, and be sure to check the fluid level regularly, especially when you have encountered higher than normal temperatures.
I'd go with #1. If you have access, a Hayden ultra-cool 403 should give enough extra cooling. You may choose a larger/smaller cooler, and any brand you like and can obtain locally. Hayden has a good reputation stateside.
tom