C4 Transmission Temp probe location?

[High Pressure]

I have a new Autometer trans temp gauge with a temp sensor that has a 1/8 NPT threaded body. The probe is "grounded" through the threads. The probe extends about .500" beyond the threads. I think most are installed in the trans pan or after the cooler. My issue is the new Art Carr trans pan is cast aluminum and does not have adequate wall thickness to drill & tap a hole for the sensor except directly below the threaded pan dip stick tube location. I don't think this is the ideal location ... the probe would be close to the exhaust down pipe. So...I am considering 2 options...

1) Weld an aluminum bung to the cast pan and drill & tap a hole. Of course, I don't have the ability to weld aluminum?

2) Install it in the C4 pressure test location (believe it is a 1/8 NPT) on the C4 (drivers side up near the bell housing). I think the temperature measured at that location would be after the pump. I would not know how well the fluid was cooled but sure could measure the "cooking" temperature... Would the probe block/restrict a required flow passage? If someone could look at a stripped down C4 case to confirm this truly an option.

3) Any other options?

[chuzie]

Tranny temp probe placement has always been an ongoing debate and a can of worms in and of iteself.

My concern would be the temp after the cooler.

I like option 1 and option 3 = Place it inline with the cooler via a fitting and secure it accordingly?

[High Pressure]

Well, I reviewed the trans temp probe location again this am.. Decided that the location below the trans dip stick location was further away from the exhaust down pipe then what I originally thought.. So I have drilled & tapped a hole into the pan. We will see how it works out...

[chuzie]

Looking forward to seeing temp data.

[bucketobolts]

I've seen a fitting that you can splice into your cooler return line (rear fitting on the tranny), though I have never used one it should work ok. The only other place I would mount it would be in the pan. Just think of it as an engine. You really don't want a temp gauge in the inlet hose to the radiator, but rather the returning cooled water or better yet the actual water in the block. And you will get a difference in temps from the block to head, front to rear of the engine. But the general idea is to keep an eye on overheating. If it overheats it overheats no matter where the temp sender is.

[High Pressure]

Thanks Bucketobolts & Chuzie, I mounted the sensor in the pan... that turned out to be the easy part. The Art Carr extra capacity pan turned out to be a pain... The inside walls of the cast pan did not have adequate clearance to bolt up to the trans case due to interference with the Art Carr reverse manual valve body. I could have sent it back but I had just modified it to accept the temp sensor. So... Sunday midday... what do I do... I break out the die grinder and made the required clearance.. It was not one small spot.. had to work on 3 sides and grind several millimeters out. Initially... the pan would not even fit joint face to joint face and the pan bolt holes were 1/2 of a hole off position due to the interferences.. I'm sure if I would have spoke with someone on Monday.. they would have told me the pan was designed for a factory C4 valvebody and not their Art Carr valvebody! LOL

Hope to wire up the sensor in the next few days..

[chuzie]

that sucks!