I don't think it is going into park for you. Maybe you could try turning the output shaft a bit to see if it goes in all the way. There is a shaft that slides in a cog when it goes in park, and it might just be off.

 

I just Googled 2005 GMC cluster and found this pic. Probably has nothing to do with your stuff, but who knows.

 

That looks like a diesel. I'm pretty sure this was 6.0 truck. I saw the engine sitting there.

 

That pic was from a Suburban that got converted to a Duramax. I think they use a 4L80E for that conversion, but I'm not sure.

 

It's going into park. The park detent is the big one at the front. I'll double check, though.

If is a similar trans to that diesel, I wonder if just changing the detent plate would fix it, or if the whole valvebody would need changed. There must be a different neutral safety switch for that diesel one, too.

 

I did a bit of research. The P-R-N-D-M-1 is for the 6-speed trannies. When in "M", the indicator changes to 1-2-3-4-5-6 for manual shift with a paddle. The mystery continues.

Going to bed now, I'll check back first thing in the morning. Hopefully someone knows what exactly is going on.

 

^^^ Exactley, thats the cluster my Duramax has.



Your not missing a gear LOL, you just dont have something right with the gear switch somehow.

 

If you have the cable disconnected then one would have to think there is an issue internally. Was there any work done to the trans since it was pulled from the yard? Also when you try to move the shifter with the cable disconnected, make sure your linkage arm is not touching the oil pan. If the valve body was off of this unit make sure that the detent for the rooster cone was installed facing the correct way. Also make sure that the rooster is connected to the manual valve. If the manual valve was missed then it might not go to low depending on where the little bar on the rooster is. Normally when this happens you will have forward in all ranges but I can not remember if all the detents will still be there. HTH Vince

 

you could just unbolt the oil pan and count the notches for the spring steal on the valve body gear select....

 

I'm going to start working on it now. I did have the trans apart to do the shift kit, so something might not be together quite right. There is clearance for the shift lever everywhere, so that's not the problem. I will count the detents in the rooster comb, too. I'll let you guys know what I see.