So im swapping the motor from my wrecked 2001 5.9 mag to my 99 5.9 mag. Both 4x4 auto and trying to leave trans in place. I pulled the motor out of the 01 yesterday no problem but then started reading forums last night and have some questions. Someone was saying to mark the torque converter and flex plate as they are keyed wich i didnt on the donor truck. Upon looking this morning i dont see any sort of key or directional specific things on it. So my question is does it matter what orientation the donor trucks flex plate mounts to the recieving trucks torque converter? Like if the doners flex is 180 out of what the recievers plate was does it matter ? Also can the torque converter just fall out and any tips on keeping it in place? It didnt on the donor but just another thing i came across. Any other tips and tricks on going back together would be great thanks!

 

I'm not saying there might be truth to the idea of timing the torque converter, but I never have and never had an issue.

The torque converter does float on the input shaft when removed from the engine and can bump off, depending on what you're doing they usually stay pretty good, but if you plan on bumping it around all a simple wiring from converter to bell housing is enough, or screw a board across the front anything simple, its safe insurance incase jack would fail or anything could happen.

It wouldn't hurt to make sure the converter is floating freely on the shaft, a seized pump/converter would lock the converter in the trans and be signs of eminent failure, but test gently as pulling very vary will release the converter seal and make a fluid mess.

 

Something you may want to consider is removing the flexplate from the donor engine and placing it on top of your existing transmission's torque converter and marking the back of the flex plate with paint to ensure the flexplate's bolt pattern lines up to make the bolt-up of the torque converter easier when installing the engine. Ensure that you have removed the crank sensor from the engine and move it out of the way before installing the motor is very helpful. The crank sensor is one of the most common things to be damaged during the engine install, since some folks leave it on the engine.

 

It's only 4 bolts, And if it needed to be oriented a certain way they would be positioned so all the bolts will only go in that way. If I'm working on something I'm not familiar with I will put paint marker on both the converter and flex plate before I remove the bolts. Had to many surprises after I get some of the bolts in only to find out the rest don't line up.

 

95 and older needed to be properly indexed, as the balance weights for the engine were on the torque converter. They moved to the flexplate in 96, so, the newer trucks, the holes should be evenly spaced.