All put back together, and low and behold, the stupid tranny leaks fluid, and doesnt seem to shift well. Like it will stay in 1st gear at aboult 3500 RPM for like 10 seconds before it will shift.

Also I'm wondering if the engine isnt eating tranny fluid also. Either that or its old and tired and smoking oil. (what color is tranny fiuid when it burns anyway?).

I've heard people talk about the vacuum modulator, and i'm wondering where it is on my truck, or if it even has one. Truck in question is a 94 ranger 4.0 4x4 with the wonderful A4LD tranny. Any help is appreciated!

 

My repair manual indicates that 93 & 94 Rangers with the A4LD tranny have a vacuum diaphragm.

It's located about midway, low down on the passeger side of the tranny case, aft of where the dip stick goes into the tranny, behind a retangular heat shield. There are two larger diameter cylindricial shaped castings on the side of the tranny case, between it & the tranny dip stick.

There should be a vacuum lne attached to it, running up to the intake manafold. Pull this vacuum line & check it for tranny fluid.
If it's wet inside with tranny fluid, the modulators vacuum diaphragm is bad, so replace the vacuum modlator. It isn't difficult to do.

With the vintage of this ride, Id also think about replacing the vacuum line too!!!!

Let us know how it goes.

 

pawpaw, do you know where this connects to the intake manifold? there are 4 hoses that come off of my intake. One goes to the fuel pressure regulator, one goes to the vacuum cansiter for the HVAC stuff, one is for the brake booster, and another is for the cruise control module. The one that i'm assuming is for the cruise control module is wet and has fluid in it, which i know is bad, but is this actually the cruise control module, or does it somehow go down to the tranny?

 

Sounds like the modulators diaphragm is ruptured & engine vacuum is sucking the tranny fluid through the vacuum line into the intake manafold. This is a common problem with this kind of failure.

I don't rightly know about the hose routing, but if that hose is the only one with tranny fluid in it on te intake manafold end, I'd suspect it's the one from the tranny modulator.

Disconnect the hose from the modulator end & check it for fluid, if it's wet, tape the new hose to it & pull it up to the intake manafold & trace it's connection point down that way. Also you'll have routed the new vacuum line in the same place as the old one & it'll be ready for hook up.

I think there is but one fastner holding the modulators heat shield on & one fastner for the clamp holding the modulator in. So it's easy to change.

 

Well thats good, wish i would have figured all this out BEFORE I just had the exhaust done and put a cat. convter back on! It would have been too easy to get to it with the cat out of the way!

 

Check coolant for ATF leak too. ATF in radiator is usual problem too

 

Just a little side note; when you remove the old modulator there is a small straight rod that may fall out. Don't lose it! and if it comes out with the modulator don't forget to put it back in! VERY IMPORTANT LITTLE PART.

 

Danged good point Rags!!!!!

 

well i figured out which line it is, and there is no fluid in it, so i'm kind of hesitant toward replacing the modulator. And there is NO WAY i can get my hand up there the way it is right now, so my question is: is the best way to get at it just unbolting the tranny crossmember? or should i do something else. I really really dont want to touch the exhaust, because its brand new and all welded together. Also will it hurt the exhaust if I unbolt the tranny crossmember and tilt the engine, i dont want to destroy the new headers/exhaust system.

 

It is a real PITA to get to with the exhaust on, BUT! it can be done! The engine, trans, and exhaust have to be cold. The hard part then is getting the shield off. Then with a little blood, sweat, and tongue twisting, you can get it replaced.

The heat shield may not be able to be put back if the bracket that holds it is rusted.

I did it on 2 trucks and got er done.

 

Now I'm a little confused here Peter!!!!!

So lets review & rethink what you've told us you've found so far, on your troubleshoot.

Are you saying you removed the vacuum line at the trany modulator end & it was dry, but on the manafold end it was wet with tranny fluid?????

What color was the fluid in the line, at the intake manafold?????

The only other "oily" like fluid, that would likely be there, might be brake fluid, if the power brake vacuum booster diaphragm were ruptured & it was sucking brake fluid from the brake master cylinders reservoir.

So, if you aren't seeing the brake fluid level drop in the brake master cylinders reservoir, the fluid you found in the intake manafold vacuum line isn't likely to be brake fluid.

When you said the tranny was back together but acting up on up shifts & leakng fluid & the engine was smoking & wanted to know what color smoke tranny fluid made, I assumed you didn't have a physical external tranny fluid leak, but a hidden leak & unexpained tranny fluid level drop, so about the only way that could happen & have the engine suddenly begin to smoke, would be for the tranny vacuum modulators diaphragm to be ruptured & sucking the fluid up through it's vacum line & into the intake manafold!!!!!

SO, seems to me we need to review your problems & findings so far, on your troubleshoot.

Does the tranny have a visable external fluid leak????

Does the tranny now act up on up shifts & use fluid, but there is no sign of an external leak?????

Did the engine suddenly begin to smoke, immediately after the tranny repair?????

If you removed the tranny modulars vacuum line AT the modulator, was it damp insde, or was it completely dry inside???? You don't need for fluid to actually run out of the vacuum line, for there to be a leak in the modulator. If the vacuum line is moist, or damp, or has an oil film inside, the modulator is suspect.

Anyway clarify if you will, what you've found so far, so we don't jump to the wrong conclusion here.

You may have two or three problems, who's symptoms mimic, or overlap each other, or maybe we've misinterpreted what you've posted & come to the wrong conclusion!!!!!

The main thing thats confusing me & giving me pause, is your posted description of the finding on the vacuum line AT the modulator!!!!!

So clarify carfully what you found there. If the vacuum line was damp, or even had an oily film inside, the modulator is suspect imo.