Burning Transmission Fluid?

[Rolkin]

I'm leaking about half a quart of fluid a week, it's not leaking on the ground at all.

When I start the truck I have some smoke coming out the back, but it only happens when I'm starting it and it has been sitting for over night or at work all day.

I'm wondering if it's getting burned somehow. Not sure how the transmission would be able to leak anywhere near the ignition system but I don't know where else that much fluid could be going since it's not leaking on the ground.

 

[jimbo74]

the tranny fluid is probably leaking out of a seal or into the cooling system if there is a problem with the radiator. it might not leave a puddle or drips because when cold, there is enough oil thinkness to clog the seal and not leak, but when warm, seep out.

there is no way your coolant is leaking out of your exhuast system....

there might be a way, if your radiaotr is toast, and you head gasket leaks, but thats highly doubtful

 

[BrooklynBay]

Check the vacuum line going to the modulator for ATF. Most likely, the diaphragm inside of the modulator ruptured. ATF could get drawn into the engine through the vacuum line.

 

[LXNavajo_94]

could this also account for atf getting into the lines going into my cruise control diaphram ?

 

[BrooklynBay]

Yes.

 

[Brett F.]

When mine went out teh ATF in the vacume system started causing pinging when in O/D going uphill.

 

[BrooklynBay]

I would recommend that you replace the modulator. It's located on the passenger's side of the transmission near the 2 servos. There should be a heat shield over it, unless it is missing.

 

[LXNavajo_94]

yep mine is bad. I pulled the vacum line off it today and yes there was atf in the line. So off to the parts store I went 12.99 for a new modulator. Whats the easiest way to get to this monster. Do I need to pull the cat or is there an easier way to get to it? Im just wondering as there doesnt seem to be much room to get a wrench on the clamp bolt.

 

[BrooklynBay]

There is an access plate on the floor above that area. It was originally intended for the manual transmission. Some people here have cut the floor a little bit to get more access, but I don't know if that is necesary, since a few people have done it without a problem. Be carefull not to lose the pin inside of the modulator. Use a drop of vaseline to hold it in place on the new modulator while reinstalling it.

 

[LXNavajo_94]

woohoo finally got the modulator replaced. I do have a few suggestions for any one attempting this repair. First off make sure you have let the transmission have plenty of cool down time before you attck it man that thing can get kinda hot. Second I found it much easier to get to after I pulled both front seats as well as the console the 2 kick plates just in front of the doors and the step molding on both sides I just folded the carpet back into the passenger floor area (also found about $8.00 of loose change under the seats lol) I also bought some sea foam I attached a short length of hose to the modulator vacum hose and started it up stuck the hose in the can of sea foam and let it suck up a couple of ounces. Alot of junk came out the tail pipe but the hose is clean now. I also replaced the soft hoses seing as they were a bit soft from who knows how much ATF being sucked through there. I checked my ATF level after and it was a little low and I topped it off. All in all it took me a about an hour and a half but I think it was worth it.And BTW Brooklyn thanks for the help it saved me a bunch of time well spent doing some flyfishing this afternoon.

 

[BrooklynBay]

I forgot to ask you to take some pictures of your step by step process. It would have made a nice how to article. I guess you could always take some pictures of the floor cut out, and seat removal process if you still want to make a how to on it. Was there enough room with the standard cut out in the floor, or was it a little on the small side to work with? I know that some people have complained about it being too small.

 

[LXNavajo_94]

tell ya what Ill do a complete write up with pics which might be a couple of weeks in the making its that time of year where busy doesnt even start to describe whats going on in my life. As for room I had enough room but could have used more although having smallish hands does help I did find that a short 10 mm wrench works better than a longer one thankfully I had both you might be able to get at it with a deep well on a 1/4 drive didnt think of it till after ward (sometimes brain storms don't come your way til after your finished ) but all in all it went smoother than I thought it would. The pin is kinda small and would be easy to lose if you weren't paying attention Mine came out with the modulator and I had just enough room to turn it upwards so as not to let it fall out.

 

[dchoward1977]

How hard was it to get your modulator out once the clamp was off. Mine won't budge a millimeter, even with a prybar. It's been on there for 12 years I imagine, and coated with rust. Hosed it down with liquid wrench, but still can't pop it out.

 

[LXNavajo_94]

mine came out pretty easy are you sure you have the clamp all the way off. there are 2 nuts one for the heat shield and one to hold the clamp on. if the clamp is all the way off then you might try turning it a little with a pair of channel locks or some other type of plier this might help break it loose. some one else might have a better idea but thats just my 2 cents worth

 

[biggeernie]

doing this job tommorow i will make a step by step guide

i am doing this job tomorrow morning on my 91 navajo. i will take a lot of pics and make a whole step by step replacement guide i just hope i dont mess up lossing the pin but i think i will do ok. i am going to take the seats out like he did. If some one can tell me how to put pics it would help me.

 

[BrooklynBay]

One way to keep the pin inside of the modulator while reinstalling it is to use either vaseline, or transmission gell. They come in a few different colors depending upon the holding power. For this kind of job, you could just use the vaseline. There are a few different kinds of modulators, so make sure that you get the correct one. The part that goes in front of the modulator is different on some modulators.

 

[BrooklynBay]

Here is a picture from Glacier991's photo gallery to better explain the difference in what I was referring to:

The first one has an adjustable knob on the back of it. The second one is the regular one.