on a turbo400 where do i tap in for the sensor, the pan, upper, or lower coolant line? thanks!

I have always put the sensor in the pan with good results. My .02$ :grinpimp:

Don't put it in the cooler line. All that will tell you is how much the torque converter is slipping.

I like putting them in the pump pressure test port (as long as it is an electronic sender).

Thanks guys!

anyone eles have a favorite spot?

yeah, the trash, both the temp sensor and the tranny... :)

where is this 'pump pressure test port' on the trans?

where is this 'pump pressure test port' on the trans?

Found this on google real quick.
http://www.karl-ellwein.org/th400/shifterlinkageandtempsensorms.jpg

The test port should be 1/8"NPT just like an electronic sender. If you have a mechanical gage it won't fit and you might as well put it in the pan. Also don't use teflon tape on the sender because it won't get a good ground and might clog up the valve body. I always use a drop of the liquid teflon sealant but dry should work too.

thats a big transmission (above) lol

yeah, the trash, both the temp sensor and the tranny... :)

im guessing u have a better tranny in mind?

Found this on google real quick.

The test port should be 1/8"NPT just like an electronic sender. If you have a mechanical gage it won't fit and you might as well put it in the pan. Also don't use teflon tape on the sender because it won't get a good ground and might clog up the valve body. I always use a drop of the liquid teflon sealant but dry should work too.

Thanks!! that works perfectly, mines got a little plug I just pulled out. the gauge is an electronic sender. I didnt even think to look on yahoo, or google. I did a search here and didnt find much. Thanks again!

Thanks!! that works perfectly, mines got a little plug I just pulled out. the gauge is an electronic sender. I didnt even think to look on yahoo, or google. I did a search here and didnt find much. Thanks again!

No problem :grinpimp:
Hard to justify putting it in the pan or somewhere else when putting it in the test port takes less then a min. The temp might be a degree or 2 higher then the pan but the gage won't have that much resolution anyways. Putting it in the test port makes the hardest part running the wires through the firewall...

Don't put it in the cooler line. All that will tell you is how much the torque converter is slipping.

I like putting them in the pump pressure test port (as long as it is an electronic sender).

Would there be any reason to ever monitor the temp in the output cooler line? Just thinking that it would be easy to hook a switch between a sending unit in the cooler line and a sending unit in the pan so you could use the single guage. Thing is, I don't know if it would provide useful information or would just be a waste of time...

I can't think of any reason but that doesn't mean there isn't.

The fluid goes from the pan to the pump and then splits, is reduced in pressure and sent to the torque converter. I think the cooler line is after the converter. Not all the fluid in the trans goes through the cooler. I have never rebuilt a th400 and am just going by memory... About all it will tell you is how hot the converter is. For the most part I think the converter can handle the heat and the rest of the trans can't??? Maybe if you are burning up converters and the pan temp is within range it would be a good idea??

I dont' particularly like putting them in the pressure tap hole, I prefer to put them in the pan. Some of the pressure ports on trans are dead headed to the test port, so you will get no flow of oil across it. Others are in line, and if the sensor protrudes too much into the passage, you will reduce volume of fluid available to the clutch packs and valve body. But again, it is just my opinion.

The oil does split from the pump, a portion goes to the valve body for shifting and clutch apply, and the rest goes into the converter then out to the cooler and when it returns cooled down, it goes back into the case and to the lube circuit. That way, the wear components, bearings, bushings, thrust washers, etc, have a constant supply of cool fluid acrossed them.