I have a 2000' Silverado and I just pulled the 5.3 and put in a 6.0. I got it all put back together and the motor started and ran fine. The problem I am having is now it won't go into gear. I am using the old wire harness and computer from the last truck and it starts/runs fine with the 5.3 computer minus the SES light. I am also using the original tranny. Another wierd thing happens now. When I shift the tranny from "3" to "D" the starter engages. With the truck off if I hold the shifter in between "3" and "D" I can actually start the truck. I am at a loss here. I have checked all the wires I can and I can't find any that might be pinched causing a short and I have no idea why the tranny now won't work when it worked fine before.

I am in desperate need of help,

Adam

 

It has to be one of the two connectors that plugs into the side of the tranny by the safety neutral switch. Did you completely take the harness off? Those two connectors sometime gum up and do not seat properly when connecting them back up.

 

My switch broke during the swap, replaced it and it worked fine.

 

Did you put a 6.0 tune in the computer for the motor. There are too many different tables to chance running the 5.3 tune in the 6.0. Also, what year 6.0 was it out of? I did everything you just did last year and no trouble. I would first check what these guys said. Also, check all of your starter wires. Did you label your wires when you took them off?

 

Are you talking about the nuetral safety switch? If so I forgot to mention I had to replace that. I broke it trying to pull the plugs out. They were stuck in there with something that resembled super glue. The indicator in the dash works fine. Shows which gear it is in.

The 6.0 is out of an '05. I started it with the 5.3 tune just to see if it would and it runs fine enough to drive it to the dealership to get it re-flashed. the only problem is the pump isn't working in the tranny. I pulled to cooler lines and nothing is flowing out.

 

You get better responses when you create ONE thread. This way everyone can see what has already been suggested or asked.
There's not certain people in certain sections.

Unfortunately I don't know how to help your issue. Sorry.

 

sounds like two different problems.... did you "upset" the torque converter in any way while it was disassembled? if the torque converter was not seated fully in the transmission you likely crushed the pump. The other issue sounds like you have a wire pinched some where, the wiring to the starter is very simple, so that would be a good place to start.

 

Yes, I was talking about the neutral safety switch. Mine broke trying to take it apart for the same reason. Could it have damaged a wire inside the connector?

 

I am sorry for the double thread but I have gotten more results on one than the other. to be honest I really wasn't sure which one to put it in so I decided to put it in both.

I did crush the pump when I first tried to bolt it up. I thought it was seated but it wasn't. I fixed it before I put too much presure on it, or at least I thought i did. I am in the process of re-checking the wires. I agree that I have one pinched somewhere, but locating it is a PITA.

I did break mine also when trying to pull the connector out. It had siezed up with something that resembled superglue. I had already replaced it before I tried starting it.

OK, I ended up figuring out that I had broke the pump in it. Today I pulled it out and took it to the tranny shop to get rebuilt. In hindsight I should have done this to begin with. The tranny had 145k or so on it and I was trying to be a cheap a$$ and not replace. I wish I would have since I would have my truck on the road by now. I wouldn't have put it all together just to find out I screwed up. So I wasted some time and effort trying to use the old tranny, lesson learned.

Thanks guys for all the help,
Adam