Location for 4L80E trans temp sender

[J Vernon Bailey]

What is best location for transmission temp sender on a 4L80E transmission? Return from radiator or line to radiator? How to identify which line is which? What about in pan?

What does everybody think?

[mhagie]

Everyone has their own opinion but I go for the simple method.
On my 700R4 I bought a B&M deep sump pan and added their drain plug kit about 1" up on the side of pan, it is tapped 1/8 pipe thread,a electric gauge sender fits perfect.
Some will say to be absolutely Correct sender must be intstalled at inlet to rad cooler but the pan is good enough for me and easy also. :D

[john8662]

A very simple place to mount the sender is in a plug already in the transmission case. On the drivers side of the transmission on the same side as the shift linkage you will find a small pressure plug. I used this for the sender installation. The new sender actually fit right in the plug hole, same thread type.

[damork]

I probably followed the more difficult route, but wanted a separate drain plug and temp sender location.

I bought the 4L80E 2wd pan which has the drain plug. Got a weld in bung from Autometer and have it located about 1 or 2 inches ahead of the shift lever on the drivers side, it is just below the upper edge of the pan - don't recall the exact dimension but enough to clear inner parts when bolted up.

The thread is a 1/8 pipe plug so it accepts standard senders from most any supplier. I use a VDO setup and all works well. I opted to stay with the stock pan as I chose to attack the heating issue with a huge cooler rather than the higher priced pans. Some of the pans approach $200 or more, my cooler was about $80 and so far pan temps stay under 175F.