Need Help Troubleshooting C6 Shifting

[fatherdoug]

My C6 auto will no longer shift into park. There were no warning signs, it just wouldn't go into park when I shut it down last night.

The transmission is a rebuilt with about 50,000 miles on it. It has worked flawlessly up to this point. All the other gears are correct. If I put the shifter in R, it does go into reverse.

I am pretty unfamiliar with transmissions. I am looking for some guidance as to whether or not the transmission is toast or can be repaired with a minimum of effort. I want to make a decision before I haul the truck 130 miles to the nearest transmission shop.

[SuperCab]

When you move the shifter to the park position I'm assuming it acts as if it's in neutral? No drive in either direction but the park pawl not engaged either?

[fatherdoug]

I hope I am answering your question, Frank. The shifter will not move all the way to the P position. The engine will not start when the shift indicator is as far to the left as you can get it. I have to move the indicator to N in order to start the truck. The truck is driveable with shifting in all other gears, and the indication of the gears is correct. And yes, it acts as if the park pawl is not engaged.

[SuperCab]

Well it's been a long time since I've messed with a C6 but it sounds like the rod that actuates the park pawl may be stuck/jammed. Hopefully someone else has a better idea than that

[fatherdoug]

Thank you, Frank.

[dustybumpers]

Chock the wheels, set the brake
climb under, and check linkage
I bet the rubber/plastic bushings are broken/ missing. and it can't work properly

see if you can push it in place at the transmission


If everything looks good, then the pan has to drop down, there's a spring in there that broke

[fatherdoug]

Thank you, Charlie. That sounds better than a rebuild. I tried manually moving the linkage from underneath, and it would still not go into park.

[fatherdoug]

Am I correct in assuming the neutral safety switch could not be part of the problem? Bear with me, I am a transmission dufus.

[Fellro]

If you have one going around the shift linkage, it is possible.

Make sure it isn't something to do with the column. My 75 had issues there, had a surprise one day when it popped out of park and took off. Should have paid attention to the lawsuits about them just going into reverse... It wasn't running, just was on a bit of a slope. Popped out of park and went to rolling. Take the linkage loose and see if you can get park. If not, then it is definitely transmission related. Then you take the shift arm off, take the switch off and try again. If still no, then the park pawl linkage or such is the cause, which only requires taking the pan off to get to.

[dustybumpers]

^^^^^^
What he said
The newer gen 8 trucks are FAMOUS for the column problem
and the park paul spring thing is self explanatory when you drop the pan

Probably time for a oil/filter change anyhooo