tranny white smoke no leaks little low on tranny fluid on start up i get white when i start up tranny i say about 1/4 quart low temp seem not move much. motor not hot oil clean full AF full clean. i did find vacum leak made truck run better

 

You have white smoke coming from the transmission? Where is it coming out of?

 

tail pipe low transmission fluid no leaks

 

what engine do you have? the trans being a 1/4 quart low isn't the cause for white exhaust smoke.

 

302 f150 4x4 auto trans 1994 167xxx miles

 

White smoke out of the tail pipe is a blown head gasket.

 

kind find that hard believe

 

Short of ATF being sucked into the engine through a bad vacuum governor on some transmissions, coolant or water is the only other thing indicated by white smoke from the exhaust - and that means failed headgasket, failed head or failed block.

 

yeah i didn't even think of that.the old c6 could still have been special ordered in '94.it looks like an electronically controlled 4r70w is the standard auto (of which i know nothing of.apparently it's an updated version of the AODE as the e40d is to the 4r100 via quick google.)

 

i was told if head cracked or bad gasket if would have AF in oil leaks on side motor or on ground. no sign of that. also I just started truck up now no white smoke I took truck spin about 2 miles I had it up 60 seem ok. I did had a vacuum leak I fix that yesterday. could a vacuum cause white smoke ? I have to take trip Saturday 400 miles round trip should I take it in to shop ?
thanks

 

You were misinformed. While those are a few indicators of those parts failing, there are also 'one way' leaks where coolant is dumped into the cylinder without cross contaminating anything else or any external signs that it's happened. You would get combustion products into the coolant, which may or may not be visible. There are chemistry testers for the coolant system for just this reason.

You can do a pressure test on the cooling system and get a better feel for whether there's a problem or not. Tools to do this are rented by the regular auto parts store suspects.

I wouldn't do a 400 mile run in a suspect truck without getting a second opinion. On the other hand, was the truck sitting for an extended period of time before you had the white smoke issue? Was this white smoke on first start after sitting? You can get a surprising amount of white smoke out shortly after startup which would just be condensation boiling out of the exhaust system.

 

Not so much updated as it is a variant. This series started with the AOD (Automatic OverDrive). In 1992 Ford updated the AOD and gave it electronic controls, changing the name to AOD-E (Automatic OverDrive-Electronic) and the rest of the trans stayed mostly the same.

A year later Ford decided it would be nice to have an AOD-E with wider gear ratio spacing. They also changed the way they name their transmissions. And so the 4R70W (4 Speed, Rear wheel drive, 700 ft-lbs rated, Wide-ratio) was born. This was basically an AOD-E with a wider ratio spread between the gears.

You can spot a 4R70W by the W cast into the side of the case, the AOD-E won't have this.

 

oh interesting.so if you don't like the wider gear spread you can just swap in an aode since all else is equal?

 

Another thing you can do, if the truck is blowing white smoke constantly.... Take a clear mason jar and hold it over the end of the exhaust pipe for about 5 minutes. That should be long enough to give you about a tablespoon of condensate or whatever out of the exhaust. If it has a greenish tint to it, like your radiator coolant then you definitely have a blown head gasket.

 

With a few changes, yes. The tailshaft housing is different between the two (the 4R70W uses a bigger output yoke) and you might have to move some pins around in the wiring connector depending on the years of the transmission.

This assumes you're going with a 1998 or older trans for the swap. After 1998 the 4R70W electronics changed slightly so if using a newer trans you will need to swap over your old components such as solenoids. The internal wiring (actual wires) was replaced with a plastic tray looking thing as well although if I remember right it will work even with the older electronics that you swap over.

I forget if there is an input speed sensor on these but if so then the computer might not be happy because it will expect to see a certain ratio between input/output speed for each gear and they won't match up between the two transmissions as you can see here:

AOD-E: First 2.40/Second 1.40/Third 1.0/Overdrive .67
4R70W: First 2.84/Second 1.55/Third 1.0/Overdrive .70

So basically the answer is yes, with some minor work. And dealing with the "Incorrect Ratio" fault codes the computer might generate.

I'm sure Mark Kovalsky will correct me if I'm wrong on any of this
It's been a few years since I owned a 4R70W.

OP, not trying to hijack your thread here. I agree with the others that you have a head gasket or cylinder head issue. These things can fail in such a way that the coolant only leaks into a cylinder or two and not into the oil.