swapping 4L80E for a Allison..on a 93 7.4 dually

[Terrick down Under]

G'day everyone. I have a 93 CC,DRW long box. 7.4 and 4L80E.

 

The motor and box have done over 400,000k's. Had the box rebuilt 6 months ago, shift kit, full tow package, strengthened torque converter, valve body upgrade. I have spent $7000AUS on this box. It drives and shifts real nice empty or with my 2700lb truck camper on. Even towing a 20'x8' trailer.

The problem is....every so often it drops the converter lockup, thus no engine breaking or o/drive, full or empty.

The last time it played up 4 hours into a 10 day holiday, then started working again about 2 hours from home. SOOOOOO frustrating. It comes up with TCC fault. The only way for it to reset is to stop the engine, wait 3 minutes and try again. Sometimes it will reset for days/weeks and some times for 5 minutes.

 

Has anyone swapped out the 4L80E and installed an Allison?????? what did you do about the ECM?????

Any input would ne gratefully accepted.

Terrick