Auto transmission 4x4 temp probe?

[Cuong Nguyen]

I remember being told a long time ago that some Pathfinders were equipped with a simple transmission temperature dummy light. When I did my 4x4 conversion, I mildy tore apart the donor automatic transmission to do some rewiring. I found an extra wire that my 2wd transmission did not have. The wire lead up to what looked like a temperature probe. I'm assuming this probe is just a one way deal to signal the dummy light that your tranny is overheating. I'm wishfully thinking I could use the probe and wire it to a temperature gauge.

 

The wire is orange and you can see the probe in the other picture.

 

[Precise1]

Nice!! Thanks for posting that. I think that ties into someone's post of taking the voltage off of the ECU input (or something) to drive a gauge rather than a new sensor. I think Tungsten on that and an older Russian member we haven't heard from, Terrano something years ago. I'll dig to put it together...

 

B

[MY1PATH]

Thanks for the picture lol.

wow there is allot of room under there. Looks like I could put a 1/8 NPT bung almost anywhere on the pan (bottom or 3sides) and not hit anything exept maybe that big round piece on the top left of both pics. FWD driver side?

 

Keep us posted, I really need to get a gauge and cooler goin. During Our cold spell the 94 was shifting really hard from 1st to 2nd.

[adamzan]

Keep us posted, I really need to get a gauge and cooler goin. During Our cold spell the 94 was shifting really hard from 1st to 2nd.

Dude that's normal. There is actually a TSB on it somewhere. Says to use the specific Nissan fluid for cold weather. It won't hurt the tranny and from what mr510 told me it is actually better for an auto tranny to shift fast and hard.

[nismothunder]

Dont forget to put your filter back in when your done.

 

Yeah,a hard fast shiftis better,theres less slippage and less heat genrated.That one of the reasons when you use a shift improver kit when towing a lot.Less wear and tear on spendy auto parts.

[MY1PATH]

 

So for clarity the filter bolts in and locates a pickup tube close to the center an sends fluid to the hole on the bottom left of picture.

Now, where does the fulid enter the pan? Does it just pour down from that opening in the bottom center of picture?

I want to weld in my sensor fitting as close to the path of where the fluid enters the pan as possible.

So if I am corrcect about where the pan fills from my fitting will be on the passenger side of the pan.

 

 

OR... I also just found Banjo Bolts with 1/8 npt openings on the head for temp and PS sensors. So what size is that banjo bolt that goes to the cooler?

 

OR... I could try and locate that orange wire where it runs into the AT computer and tap into that...

 

EDIT: 94FSM AT-36 shows that orange wire/sender as acutally just a heat triggered swich hooked directly to the warning light. It becomes Green/yellow stripe at the harness.

White and Black should be the actual sensor and they become Red and Black at the harness. Red runs to the AT(pin12) computer and Black Runs to both the AT computer(pin15) and the ECU(pins 29&21).

Edited December 6, 2010 by MY1PATH

[Cuong Nguyen]

Yes,fluid is sucked up by the filter through that circle hole on the bottom left to the TC which eventually spits everything onto the clutches/gears and all is drained down the bottom through all the orifices most mostly through that big hole you speak of in the bottom center.

 

So at what temperature does the sensor trigger the dummy light?

 

[MY1PATH]

So at what temperature does the sensor trigger the dummy light?

That, I could not find. I'm guessing too High tho lol. But if I had to pull a number out of my @$$ I'd say over 210F.

 

Thanks for the info on drainage, do you think you could also measure the Banjo Bolt for the Cooler lines(12mm x 1.25?). I may consider just getting one of those if I can't find a spare pan to weld on... I like to avoid vehicle down time...Or I could just make the wife drive the doge and take all the time I need in the world doing it.

 

http://www.summitracing.com/parts/RUS-640700/

Edited December 7, 2010 by MY1PATH

[GrimGreg]

 

So at what temperature does the sensor trigger the dummy light?

 

 

I think I remember someone saying 280 deg.

[Precise1]

I can not remember but I do remember it being in the two hundreds and much higher than I would want to see. I'm certain it was posted in a thread, I think by someone living in Colorado...

 

B

[MY1PATH]

I think I remember someone saying 280 deg.

 

 

owch!

 

hey Cuong, could you take that Banjo bolt for the cooler line out and measure it?

I'm guessing its 12mm x 1.25 but I don't want to drain my tranny just to find out.

[Cuong Nguyen]

I would help you out but the trans is not here with me

[MY1PATH]

 

EDIT: 94FSM AT-36 shows that orange wire/sender as acutally just a heat triggered swich hooked directly to the warning light. It becomes Green/yellow stripe at the harness.

White and Black should be the actual sensor and they become Red and Black at the harness. Red runs to the AT(pin12) computer and Black Runs to both the AT computer(pin15) and the ECU(pins 29&21).

So Digging into the 94FSM more I have found that that aswer Is NO, you cannot run a regular tranny gauge of the factory temp sedender for the ecu. I ran the temp sender tests for the factory unit (AT-48) on the autometer unit I plan to install and the Factory unit puts out much lower voltage signals.

 

Here are the temp/voltage specs for the factory sender:

68F = 1.56v ---> 175F = 0.45v

 

Here are the temp/voltage specs I got out of the autometer sender:

70F=7.5v ---> 180F = 5.3v

 

No the sender is not broken as its gauge read the same thing my thermometer did and If you wired it up to the factory sender you temperature would would register beyond the limit of the gauge.

[Cuong Nguyen]

I would help you out but the trans is not here with me

[MY1PATH]

Got my tranny filter today. Inside it was a note stating that the filters with square pickup tube(like the one below) should not be used because are obsolete and do not provide adequeate protection... Just thought Yall should know...

[Cuong Nguyen]

Was it an OE or aftermarket? I imagine if there was a service file if if was factory. I know in the case with the z31 oil pickup tube the discontinued the old style and started l producing new replacements that utilize the flat gasket instead of the faulty o ring design. Only issue is that I don't know when I'll ever get my replacement tube since it's on back order..

 

I wonder what the new style looks like. I wonder how the square style can cause problems. I can only think the screen is so fine and can clog easily. But you would have to low on oil to be spitting clutch disks.

Edited December 11, 2010 by Cuong Nguyen

[MY1PATH]

the new style has a round tube where the square one is on yours and a few stampings at differant angles on the boad side.

The overal shape is the same.

http://info.rockauto.com/getimage/getimage.php?imageurl=http%3A%2F%2Finfo.rockauto.com%2FWIX%2F58906.jpg

the board won't let me post the image here

[Cuong Nguyen]

I guess the design change was to decrease the likelihood of sucking up air or no oil from sloshing around.

[Towncivilian]

My R50 is 2WD, and did not come with a bulb installed in the "A/T OIL TEMP" dummy light position. I have installed an LED bulb there and it lights when the ignition switch is "ON". I have an auxiliary transmission cooler so I will likely never see this light illuminate. Next time I do a pan drop, should I look for a similar probe as in the OP? I'm wondering whether this dummy light actually would light at a certain temperature on my 2WD.

 

For the in-pan filter, I don't recall what my Beck/Arnley aftermarket pickup screen looked like. I know it had a round pickup tube, but I don't know what the screen itself looked like. Is this something I should be worrying about with my 2001.5 RE4R01A?

[adamzan]

I used a beck arnley kit on mine as well and I haven't had any problems in the 70,000km's that it has been on there.

[Towncivilian]

I found a pic of a 2WD 2001 RE4R01A:

 

 

 

Here's what the FSM says about the temp sensor:

 

 

As far as I can tell, it doesn't have one. Something that looks like a couple black wires are visible, but there is no sensor. Am I correct?

Edited October 4, 2011 by Towncivilian