Okay well makes more sense there was a lot going on in that other thread that I didn't understand. So doing the swap is more work in the long run then finding another 4r44e trans or rebuilding the one I already have?
Do you know why my trans will not go into drive but will go into the other 2 gears?
lol, I hear ya.
It's not hard work if you know what you're doing. But the computer issues are where the common back yard mechanics skew off. In all honesty, this route would probably be cheaper. The 4R44E-5R55E transmissions should really be built by people that know everything about these transmissions. But unfortunately, most shops don't have these people. All the transmission shops do is basically throw parts at the trans, replace whatever they physically see is wrong, and/or replace the part that the code said has problems. You never really get a full rebuild. You always end up losing because the parts that should have been replaced did not get replaced, and you'll most likely end up having to drop the trans again 10,000 miles later when those other parts get replaced. What sucks about a quality full rebuild is that they cost upwards of $2k+. You get what you pay for, and paying $1K sadly isn't enough.
Now on the other hand, if you replace this 4R44E with the 5R55E and get it working, you may end up having problems with the 5R55E as well, and end up having to have it rebuilt down the road too. So it's really a game of chance as to what you want to do. I'm not saying the 5R55E is gonna blow tomorrow, but it's just something to consider. But hopefully the 5R55E is stout and will be problem free for a long time.
As for your problem at hand currently, from what I understand, when you put your truck in reverse and drive, it seems like it's in neutral. Well, the quickest thing to check is whether or not the Manual Lever Position Switch(Neutral Safety Switch) is aligned correctly. If this out of alignment, it could very well cause the truck to feel like it's in neutral, because it could very well be in neutral. The MLPS is located on the driver's side of the transmission. You can't miss it, it's a big half circular black switch with a lever coming out the side for your shift linkage. Block the wheels, set the e-brake, unplug the MLPS wiring connector, and pop the shift cable off the shaft. Then, remove the gold selector arm from the trans lever. It is a pretty big nut, I can't remember the size. Once you get the selector arm off, look for the word Neutral on the body of the switch. You will see directly below the word Neutral that there is a vertical line on the switch itself. This is Neutral for the selector switch. Now look down at the little white plastic ring. You should see a little tooth in the inner section of the ring. When you find the tooth, you should see a line similar to that of the neutral line. Note it's position and how far it is from the Neutral line. If it is not aligned with the Neutral line on the MLPS switch body, then your MLPS is out of alignment. Manually put the center ring back in line with the MLPS. Then reinstall the MLPS, making sure you do not knock the ring back out of line. Make sure when you tighten the selector shaft that you put it back in Neutral or else the truck will not start. Park is towards the back of the truck, so if you lose your place, turn the selector switch towards the rear of the truck, and then count from there. Once this is done report back and let me know how it turned out. If you need a diagram, I can make you on tomorrow.