Dan DuBief

Hey Folks,

Recently rebuilt my 4L60E, had the output shaft snap (I blame the tune + 35in tires). Anywho, upgrade pretty much everything in the trans (Including hardened Sonnax Shafts, 5 pinions, only the original input drum and rear support and some steels were reused) And after reinstalling and going for the initial test drive, I'm only able to go forward in what seems to be 2nd or 3rd gear. As well as reverse. No oddball sounds coming from the trans (What I can hear over the exhaust anyway...) Everything I've researched points to this being electrical (Which I am quite grateful for, but am not 100% ruling out mechanical issues).

So far, I've verified fuses are not blown. Connectors are all connected and fully seated (my new Rostra transmission harness seems to have come loose in the bore on the case itself, but confirmed that was fully seated to the main harness).
I have yet to do the following:
Verify 12VDC + and Grounds going to the transmission connector
Dropping transmission pan to test solenoids

Using HPTuners VCM Scanner, I didn't have any codes, validated I had one O2 sensor that was not connected and repaired that, but no TCM or transmission related codes to be found anywhere. I am able to see the transmission shift into position and being reflected in the CAN data. D 1 2 3, etc. As well as commanded gear selected. One question I have here, is using VCM Scanner is this what the PCM is telling the transmission to be in? Or is this the data from the pillow switch in the pan telling me the pressure is routed that way from the valve body?

4x4 works properly, so I believe its just the transmission at this point where my issues lie, (Along with a starter that needs shimming).

I plan on digging into the transmission connector this afternoon and confirm that the cable is getting 12VDC + to the pink wire, as well as a suitable ground is present. Aside from that, any ideas I can pursue so I can prevent myself from potentially having to drop this transmission?

Appreciate any insights you all can give!

Thanks!

Dan DuBief

Well, ran thru all grounds going to the PCM connector, and all good. Also verified the 12v is good thru the IGN0 fuse in the cab, and down to PIN E on the transmission connector. So looks like next step is to drop the pan, and test me some solenoids and harness. I'll likely also pick up a spare valve body and harnesses from the pull yard to make a bench harness (or intermediary LED Test harness) to validate both operation out of the truck and back in the truck using the stock wiring.

Also need to find me a pressure gauge as well. More to come.