So my 4l60e shat itself a while back. (broken drive shell)

I rebuilt it myself and purchased a new remanned stock stall torque converter.

Everything shifts perfectly, but I have no TCC lockup. I only have one fault code, the dreaded P1870. I performed the TCC regulator valve repair during the rebuild so its not that.

Any suggestions on what would cause no TCC lockup? I'm kind of out of ideas on what to check.

I presume ill have to pull the trans back out (sigh) but i havent yet because to be honest, i don't know what to check.

 

what converter was it. I would suspect it if your confident in your work on trans. but then I dont know squat about trans... lol. mine did that and I sent it back to patc and had em go through it. they ended up rebuilding converter and trans.

 

haha yeah. Basically I spent 7 months studying the transmission, maticulacely tearing it down and rebuilding it from scratch using mostly new parts - just as a project/learning experience for me.

I've obviously made a mistake somewhere, from my research:

- TCC regulator valve in the valve body - I pulled that and checked it. I actually used a reaming tool so theres a possibility that i reamed it incorrectly and caused a leak. I'v ordered a cheap chinese vacuum tester so I can test the work, but it will be a few weeks before it arrives.
- TCC Apply valve in the pump - I removed the valve and confirmed it's correctly inserted. this was correctly inserted. I can't vacuum test the circuit without dropping the trans again.
- O ring on the input shaft - I thought i had put that on but now I'm second guessing myself.
- PWM and TCC solenoids - tested with a battery and commanded them on with a tech2, confirmed they are working correctly. Resistance values are correct.

So my plan is:

Drop the trans and check the o-ring. If the o-ring is in place, vacuum test the pump and valve body TCC and PWM circuits.

If no problems are found, assume TCC was DOA and send it back.

Just figured i'd post my troubleshooting steps incase it helps someone. a missing o-ring on the input shaft would be the most likely cause I think, given I trust the other repairs I did.

Wish me luck!