4l60e crazy shifting issues! long story behind it

[jessimusprime]

Hello everyone, I'm new here and hoping I'm posting in the correct area. I started rebuilding automatic transmissions about a year ago and have been a mechanic for over 10yrs. Every transmission i have done has come out very nice except one in my personal vehicle. It's a 4l60e in a truck and i swear ive pulled it back out half a dozen times (two just for fun). The initial failure was just shot 3,4 clutchesand worn bushings. I decided to go with the alto red clutches and raybestos steels, beast shell, sk shift kit, vette servo, drilled plate, and pinless accumulators. It worked ok but was a bit sluggish, i ended up pulling it back out a couple weeks later to figure out that it was an easy fix by turning up the epc solenoid a bit. Installed back inthetruck and ran pretty good. I was happy but wanted a harder shift so i pulled pan and added just a bump more on the epc and called it good. Truck now ran nice. About a month later i was going to do the boost valve and there was a bad lip keeping the valve from coming out so i pulled it again and did the boost valve. Reinstalled only to have to pull it again to change the reverse input drum and band as failure occurred and i don't exactly know why. Fixed andran great again. Now the weird part. ... Three days ago all of a sudden 2nd gear was slipping horribly. I continued home 3 miles with no bad problems. Pulled Trans and opened it all up to find a burned band from what i believe tobe a bad servo seal because 4th was still good. Replaced drum again and band and added superior shift kit, Trans go plate and pinless forward accumulator.cleaned and reassembled valve body. Got it back in the truck and it's all bad. Put it in drive and it engages better than ever. Takes off great in 1st and then no shift to 2nd. I throw the shifter in 2 manual and it slams into 2nd but won't shift to third. Throw it in 3rd and it shifts and revs like neutral. But if i unplug the harness and put it in 1or 2 manual it will start in 2nd and i can up shift manually and it feels great. I can't figure it. Out. Any suggestions welcome. Thank you.

[moesplace]

solenoid on VB did you replace them and make sure all the valves move free that control all of your shifting

[jessimusprime]

I did clean and re assemble the entire valve body and couldn't find and problems. I tested the solenoids and they all checked out great. I'm wondering if the pressure manifold switch could have failed, i did use paint thinner to clean it because it was so nasty. But is weird because if i unplug the connector you can manually run it from 2nd through 4th and feels great. Thanks for the response

[moesplace]

had a problem a bad solenoid shorted when it got hot drove dealer nuts and me it was on there dime

[jessimusprime]

They are cheap enough so i will throw some solenoids at it but I'm thinking about just buying the whole valve body with electronics. Any body ever used the remanufactured valve body? Comments?

[jessimusprime]

Ok dropped pan and ran tests on solenoids. Sol a 22.7 ohms sol b 22.5. I also ran power and ground to both and they click and sound fine. The 3 2 solenoid was replaced 6 mnth ago and tcc solenoid is new due to breaking the old one as it came out. I don't know of a way to test the pressure manifold switch but I'm really leaning toward that being the culprit. I watched a video saying that a bad pressure manifold could cause it to drop out of gear or "neutral". Mine still will not shift at all and if it finally does it just neutrals. Any help would be great. Thanks guys.