my 1992 4runner (3vze) automatic is the most reliable car ive ever driven, however my family recently purchased a house in the pocono mountains in pennsylvania. we'll the last 2 trips ive taken up there have been beating the crap out of my trans. im assuming its overheating, because there are no leaks(hhad it checked by a mechanic) but when cruising @ 70 or driving in the hills the transmission spews fluid out. i can tell because ATF is being thrown all over my rear window and the cars behind me. The trip i took last weekend i had to add 3 1/2 courts of ATF over the course of the weekend. I was checking it constantly because i just replaced the engine and am in no positiion for a new trans. so i gotta save this one. any ideas of how to solve this? There is a trans cooler hooked up to it but i am considering a larger one. Does anyone think this will sove my problem?

Thanks for any advice!

 

Wow that's weird no leaks but it spews fluid out? I guess you can't tell where the ATF is spewing from? Is it maybe the vent on top of the tranny?

 

yea thats what i was assuming when i was told there were no leaks. i cant tell exactly where from because the entire underside is wet.

 

overfilled ATF fluid perhaps?

 

Get under there with a can of brake cleaner and clean it up. Then watch close for a few miles to see where it's coming from. How can a machanic say there is no leak with fluid every where? Did he put dye in the ATF or something?

 

no it wasnt overfilled when i noticed it on the window i checked the fluid level and barelly got a reading on the dipstick. and yes mt goat dye was added I work at a chevy delaership (after the first time it happened, i watched it closely fo rthe week following and no leaks) and i trust the mechanics and their evaluation. however their knowledge of yotas only goes so far. the spewing only occurs on long trips at speeds inexcess of 65. or when the engine is under load(uphill etc...)

 

Has your ATF temp light come on during those trips?

 

no i have never seen the temp light lit up on my truck. is it possible its a blocked screen or something within the trans? but that still wouldn't explain why it only does that on those trips.

 

Might check your cooling lines and cooler to be sure they aren't blocked or pinched or somehow restricting flow. An easy way to do that is disconnect the return line and put it in a bucket and have someone start the engine while you check the flow. Just do this long enough to verify the ATF is flowing good and shut the engine off ASAP and of course top off the transmission with ATF after.

 

id get a temp guage then theres no question.

plumbing an aftermarket secondary cooler is fairly brainless and ive seen it make a noticable diffrence on my fluid temps (in conjunction with the guage)

 

Yeah I agree, the only way to know if its a slight overheating issue would be a trans temp gauge, I've heard the idiot light only comes on when it's really cooking, like over 300 deg F IIRC.

I'm trying to picture what would cause that much sudden fluid loss and the only thing I keep coming back to is a pressure build up inside the tranny causing a blowout of fluid past a seal or vent. What could cause this? One possibility is a vent that is blocked causing a buildup of air pressure. Or maybe a cooling line that is restricted.

 

yea... im afraid of it being something blocked internally. the steel lines to and from the trans to the cooler are brand new, because i had the replaced when the engine was replaced with the reman'd one. its a real PITA to find a trustworty tranny shop around here too. I used AAMCO with my firebird and they really screwed me over. poor quality, retured the car not fully assembled and damaged(claiming the tow truck driver did it when i know he didn't, i was there) so i know if i go to them theyre going to give me the "its the end of the world speech", i might take it to the stealership just for some insight.

I'm considering a trans fluid temp gauge but is it possible to put the sensor in the hose leading to the cooler rather than within the trans itself?

 

Yes I'm doing that now with this:

 

will probably order it tonight. anythoughts on a digital gauge? are they efficient enough or should i stick with the good ol' needle?

 

You said that there is a tranny cooler hooked up to it now. Is it hooked up to where it flows through the original cooler on the radiator and then through the aux. cooler and back to the tranny?

 

yea, thats how its set up as of now, but the auxillary cooler looks like a piece of crap, its located behind the grill infront of the radiator, i'm looking at getting one similar to the B&M with the 12V fan attached to it for optimal cooling.

 

Mine is an electric full sweep gauge from Isspro: http://www.egauges.com/vdo_mult3.asp...=EVA-R&Units=E I'd stay away from the mechanical gauges I guess, I don't see any reason a digital read out would be less efficient, whatever floats your boat. The Isspro gauges match my factory gauges well, with black face, white numbers and the red pointer. You can order the green bulb covers to match the factory green lighting we have and wire the lighting through your dimmer switch so it's not too bright.

 

thanks for the advice mt goat and everyone else that has responded. it has great value to me. But what im still trying to figure out is, is there somekind of vent on the transmission that when the pressure gets to high within itself it opens up to release fluid? or is the trans completely sealed and i'm blowing fluid out past a seal?

 

Well I just went and looked at my 93 A340H tranny and took some pics for you. This may be what you're talking about, its at the top of the tranny rear the bell housing:


This vent is at the back on top of the transfer case:


Those were the only vents I saw. To access the first one it might be easiest to remove the shifter from the floor and look through the hole in the floor. If there is ATF all over the top, thats probably where its coming from. Notice mine looks a little oily and dirty right around the vent opening.

 

mt goat you are my hero, that appears to be where the fluid is coming from, now the question to be answered is why?, for now im going to assume its an overheating issue. i just ordered my trans temp gauge so i hope to have it in this weekend. speaking of that, how and where are you mounting yours? I was looking for a single a-pillar pod but am unable to find one. do you know of a manufacturer?