This is a tad bit of a long read...sorry. 99 F350 7.3l with 4R100 trans. About a month ago I took out a monster trans that had about 60k on it and it was burnt up. No warranty. ..customer bought another monster. After the install when going into 4th the torque converter would instantly lock making it feel as though the truck was falling on its face. Monster had me do some data logging and from the info I provided they determined it had a bad solenoid pack. They sent a new one out...when I went to install the new pack I noticed when I dropped the pan that the fluid was iridescent looking...a bolt for the valve body was in the bottom of the pan and lots of material stuck to the magnets....needless to say that trans only lasted about 2 weeks after putting the solenoid pack in. Fast forward to today..got trans number 3 from monster under warranty. After the install everything seemed good. About 30 mins into highway driving the od light starts flashing. ..subsequently the P0741 code. I did put 2 new wire pigtails on the front and rear speed sensors. The pigtails were a ford service part but they were a bit different in design. I am pretty sure the wires are correctly oriented..if not would this cause the issue. I really am leaning towards a bad solenoid pack again. My buddy thinks the TC isn't seated properly....where do I start? Also has an edge programmer on it..but it's been on the same map all this time

 

The code means there is a problem with the torque converter clutch solenoid OR the wiring to the solenoid. The speed sensor pigtails cannot cause this code. Neither can the torque converter not being seated properly.

It's also REALLY easy to diagnose the converter not seated properly. If it isn't, usually you can't turn the engine over, but if you can, it means the pump gears have been busted to pieces and the converter snout is ruined. Either way the truck won't move if the converter isn't seated properly.

The problem is most likely a bad electrical circuit between the PCM and the transmission, but if you reused the same coolers with transmission #3, then contamination from the earlier failures could have put debris into the solenoid causing it to stick.

 

The cooler was flushed very well using several cans of cleaner designed for trans coolers as well as compressed air. The fluid was running pretty clear by the time we used the last couple of cans. Not dismissing what you are saying. ..anything is possible. The fact that this problem didn't exist on trans #2 but it does on trans #3 makes me think its an internal issue. I'm not confident in monsters quality at this point

 

What internal issue can set code P0741?

 

Solenoid pack? I wasn't saying internal as to reference a major part problem..perhaps I misspoke.

 

The only other thing I have skepticism about is the actual tc itself. I read an article about minimal wear on the tc hub causing more fluid to pass than what would be allowed under normal circumstances thus causing the pcm to detect slippage. ..maybe I'm wrong on this one.

 

Maybe that's possible. It won't set a P0741 code.

 

I'm sure monster will want me to data log it while driving. So you are thinking solenoid pack or wiring between the pcm and trans? Or some debris that's got the solenoid fouled up? That's what I gathered from your post.

 

Yes. Most likely is something wrong with the wiring between the PCM and the transmission. Also possible is some debris making the solenoid stick, or a bad solenoid.

 

Hi mark...monster sent a new tc and a new solenoid pack. After install the same issue persists. Do you have a schematic of the wiring...some guidelines as to what I should be checking please

 

I don't have a wiring diagram. When you find one, you need to check each wire to the torque converter clutch solenoid for continuity, short to ground, and short to power.