4L80e Questions.

[cleansquare]

So this 4L80e I got rebuilt is supposedly a 93-93 year model. Im installing it into my carburated 85 c20. Already got all of the computer stuff sorted out and installed. It has a new converter. The wiring harness inside the pan is the new style that I had added to fit my standalone controller harness. My questions are these.

1. There are two connectors on the drivers side. One has to be the speed sensor. Which one is it and what is the other one? Heres a pic. My harness only has one connector and it seems to be the same size as these I just dont know which one. The bottom bigger plug is the main control obviously.



2. This transmission has quick connect plug ins for the trans cooler lines. They are also very far apart, much further than my original screw in type lines which are quite close to each other. Should I find some quick connects, and use rubber hose to connect them to my existing lines? Anyone know where I could find such quick connects?
Here is a picture of them.



3. I was informed that my th400 dipstick would not work with this trans. Im assuming I need to find one from a 4L80e equipped truck. ANy idea where to aquire one from?

4. Driveshaft shortening. I measured the 4L80e from tip of bell housing to the end of tailshaft. 31 1/2" (the pic shows it wrong).

Measured the TH400 from tip of bellhousing to end of tailshaft and its 28 1/4". This tells me the driveshaft needs to be shortened (since the 4L80e is longer by 3 1/4")...correct? This is critical because my front driveshaft is not a slip yoke, its bolt in to the trans yoke and then its hard bolted into the frame at the carrier bearing. The rear driveshaft length will not change. As pictured here.

Is this an acceptable way of measuring to get this measurement?



Thank you to anyone who can help.

[cleansquare]

Im getting some quick connects from my trans guy to just cut my other trans lines and connect them that way.

I've been told that the rear sensor is the output speed sensor but still have nothing to plug into the input.

Talked to the DS guy and hes going to cut my driveshaft down tomorrow

Going to order a braided steel dipstick flexible tube from summit.

[storm9c1]

OK, that does not look like an early 4L80E to me. The early ones have threaded cooler lines and they are similar to the TH400, both up front. The 80E was eventually redesigned to move one line toward the rear to fix a lubrication issue. And the quick connects were added.

For the sensors, the rear one is the speed sensor, the front one is the input RPM sensor. You only need the front one if your computer needs this to calculate torque converter slip. Otherwise you need the rear one for VSS.

Dipstick -- that's an easy one. Use the stock GM locking dipstick. Here are the PNs:
dipstick tube: 15729870
dipstick: 15969246

And the torque converter cover: 15687274 -- make sure this is the stamped steel version. There are two PNs and I may have them mixed up.

Drivesharft: I was always taught to put the trans+engine in the vehicle THEN measure your drive shaft length! This is the only way to know for sure what you need. Adding a different trans may require you to move the whole combo forward or back. I had to move my engine about 1/2" for the trans pan to clear the front cross member on my C30! If I had the driveshaft cut before I found this out, there may have been a problem. But I waited and did it last.

[GRADYS Performance]

the torque converter cover: 15687274 -- make sure this is the stamped steel version. There are two PNs and I may have them mixed up.

Will this part number fit the 91-96 4L80E case with 3 bolt holes on each side? I believe it is considered a K or 4WD case. It is being used in a 2WD application.