First atf change on my rebuild transmission and I figured I'd throw in a transgo shift kit in it while I was in it. I really wish I took readings of pressures before I tore into it. Now I'm looking at 90 psi at 1200 rpm dead stop and 120 psi with the tv valve all the way foward at 1200 rpm. I've done a bunch of reading on this site and read some great guides. But I cant find someone with the same problem I'm having. According to transgo I should be seeing closer to 120 -155. Only other mods to the transmission was a single disc billet torque converter and a upgraded 2nd gear strut and anchor. Am I ok to run at these pressures? Is my pump going out? Or do I need to upgrade the accumulator piston and governor solenoid? (Seing 150 psi at WOT in od ) thank yall in advance. FYI amazon sells a 47re  transmission pan with a drain plug for 27$ if your like me and too broke for the fancy billet aluminum ones. 

I have a @Dynamic built stage 2 transmission; below are the line pressures the transmission now has:

• stopped in drive 85psi @800 rpm
• light throttle 2ed gear 105psi
• light throttle 3ed gear 110psi
• light throttle 4th gear 120 psi @2200 rpm 
• full throttle 1-2 shift 180psi @2800 rpm
• full throttle 2-3 shift 175psi @3100 rpm
• full throttle 3-4 shift 150 psi
• 100% throttle 4th gear w/torque converter locked 160psi @70mph 

As for adding a drain plug in the transmission pan there is an article in the 24 Valve 2nd Generation transmission section.

https://mopar1973man.com/cummins/articles.html/24-valve-2nd-generation_50/52_transmission-transfer-case/adding-a-transmission-drain-plug-r674/  

 

 

 

Thank you for that! I've only recently been reading up on @dynamics work. Wish I had found it before I put this shift kit in. But those numbers give me something to aim for. Where your transmission is making pressure is much diffrent then mine. My highest pressure is at WOT 4th gear 150. WOT 1st gear is about 120. 

Does anyone know of a more unlikely cause for a p0720 code to pop? I've changed out the output shaft speed sensor (factory one had a pretty obvious failure) but now I'm wondering if something else in the transmission can be causing it. 

Ohm test the wires from the PCM to the transmission speed sensor for open circuit and check the connectors for corrosion/poor contact. 

Edited August 28, 2024Aug 28 by IBMobile

Think I got it solved checked all wiring and found the connector was full of atf from the original failed sensor. Cleaned it out and can't seem to get it to act up. Also had a failed (missing)  0 ring on my 1-2 shift accumulator piston causing some leakage internally. I officially broke the transgo customer service. Over 90 emails back and foward and dropped the pan 5 times. They were very helpful but we officially determined I need to just go 6 turns on the pr valve instead of the normal max of 4 to get me to the 150-range for line pressure. 

Good to hear and thanks for the feedback.