I did the wire changing in the plug from 4L60 to 4L80 and the pin 45 to the #26 position in the T42 plug. I used the Gen 4 version since I am using a E38 and T42 combo.
On pin E of the trans plug, I have 12 volts. The trans is full of fluid. The wiring harness in the trans is new. All new parts in the trans.
I can start the engine and move the shifter thru the gears and --nothing. Any ideas where to start trouble shooting this??
Thanks
With the trans plug removed, still no gears. should have 2nd with the plug removed.
I tried HPTuners scanner to force it into any gear---no gears

 

Conduct a pressure test.

How many qts of fluid?

 

Hi Jake, It's been a while since I filled the trans. I don't remember the number of quarts. I measured the dipstick with the pan off and adjusted it (Lokar). Shows full---engine running in park. What pressure gauge can I use and hook up point.
My GTO (sold) 4l80 is still running great---long time. I am in FL now.

I ordered a pressure tester gauge.

 

ZERO pressure in all gears at idle.

 

It sounds as if the torque converter is not fully engaged into the pump. What is the gap between the converter mounting pads and the flex plate?

 

It was 5/32"

 

If you have 0 presure one of three things it can be, Wrong converter not engaging put (very unlikely) Broken pump (Probable) PR valve snap ring was not seated and blew out of pump. I would drop pan look at that first since got to drain anyway , Then if its not that start pulling it back out to inspect pump . Those are the only things short of no fluid in trans that could leave you with no line at all .

 

Stock 4L80Es that have a Gasoline Engine, should have 1/8" to 7/32" Torque-Converter Pull-Out.
5/32" is Fine, as the Minimum is 1/8" and that is equal to 4/32".

Remove and Disassemble the Oil-Pump.

 

I will pull the pan and see if anything jumps out. And get ready to pull the trans.
I am not looking forward to doing that messy job. I was ready to drive this thing.
Maybe I forgot to install the filter--Naaa
Thank you guys for helping!

 

DING DING DING !! Snap ring in the pan and PR valve blew out. THANKS!!

 

Snap ring goes back on such that the flat side of the snap ring faces away from the boost sleeve.
OEM part number for the snap ring is 11503348 if the one you have is messed up.

 

That will indeed make 0 presure lol but easy fix ay least just make sure its seated in the groove this time.

 

I am a little worried that the trans is damaged from the idle time that I have on the new motor. I had no reason to try and put it into gear when I was trying to get it running. Trans was unplugged. Was that the same as running it dry with that relief valve blown out? There was a tiny bit of clutch material in the pan.
Thanks

 

Its unlikely you did any damage to to clutches etc , and the pump would have still pumped would have just been dumping back into pan , About the only and I would say MINOR WOULD BE THE TWO BUSHINGS IN THE PUMP. assuming you did fill the converter as best you could . I would go with it and run it myself.

 

The tiny bit of material is probably just what I call hidden trash can be in nooks and crannies in pump, cooler, planets and is always present after a build to varying degrees . clean builds will have very little , But still its why I have people change filter at about 500 to a max of 1000 miles first change then normal routine after .

 

Thanks again!

 

Trans goes into all gears---sitting on the rack. Not driveable yet. 100# pressure in all gears at idle. Gotta bleed the brakes and go for a drive. It would be nice to have a windshield at some time also.