Originally Posted by Rogers 07

Well, It finally broke. After 130,000+ miles I had to get my car towed because of a part failure. I had just pulled into a dinner to get lunch, went to shift into Park and.... Nothing, The shifter just moved from D to P without moving the Transmission into park (Essentially it was stuck in D) So I just turned the engine of and called the tow truck!. When I got it home, a quick inspection proved the cable was indeed broken as the shift lever arm in the transmission worked fine and of course the cable link to the shift arm appeared to be in good condition (Meaning it was the end that attaches to the shifter itself that failed.. Of course !) Looking on line, I found a new GM Replacement cable for only $39.00 so that was good. Knowing it was going to be a PITA to change it, Here are the steps needed to change the cable.
1. Disassemble and remove the center console.
2. Unbolt and remove the shifter assembly (Only for 10 mm nuts)
3. Jack-up the car and secure with jack stands or (use a Lift)
4. Remove the exhaust center pipe (H pipe) section.
5. (Optional) put it really helps with access to the cable attachment point behind the shifter...Remove the torque tube cover, All the bolts have to come out and it seems like a thousand of then are in there!
6. Pry the cable connection of the transmission end shift arm (It just snaps on and off)
7. Remove the cable from the shifter, In my case it had already broken off at the shifter cable connection. It just snaps on and off just like the transmission arm end.
8. There is a cable retaining bracket that holds the shifter end of the cable about 6 inches behind the shifter attached to the tunnel. You have to push the cable up at the bracket to get it come out of the bracket (This is no fun as there is not a lot of room to reach up there.)
9. The transmission arm end of the cable is retained by another bracket bolted to the transmission, to remove it, there are two tabs you squeeze inward on the cable and it allows the cable to slide out of the bracket.
10. Once both ends are free of the retaining brackets, the cable can be removed from either end just by pulling it and guiding it out.
NOW for the fun part!!
11. Install the new cable into the tunnel and route it up where the old cable went. I recommend connecting the shifter end of the cable into the tunnel bracket first.
12. The cable can only be installed into the tunnel bracket in one position (Or orientation) , the cable must be guided up over the tunnel bracket, them pulled down into the bracket so that the cables retaining slot is fully engaged in the bracket. (Make sure it is in the right position or the shifter will not work properly !!!)
13, Install the other end of the cable into the transmission bracket, again make sure the two retaining tabs are fully engaged as you push/Pull the cable thru the bracket, (Again this end only goes in, in one position as there is a locating tab that must be correctly oriented in the bracket as well !! Were talking fun here !!
14. At this point Make double sure both ends of the cable are properly installed in there respective retaining brackets!! Repeat this step as often as need until you are 100% positive they are installed correctly!!
15. NOW reinstall the shifter and reconnect the wires connections that got to it.
16. Snap the shifter end of the cable onto the shifter pin, This can be done as you're installing the shifter in to the tunnel or from underneath if you removed the torque tube cover.
16. If all is going well, turn on the ignition, but don't start the engine (You don't have the exhaust hooked up yet). Push the brake pedal and you should hear the shift solenoid "Click" when you hear it, Move the shifter in to the Neutral position.
17. Before you hook up the Transmission arm end of the shift cable, Make sure the transmission is in the neutral position. To do this move the Transmission arm towards the rear of the car as far as it will go, it will stop clicking as it moves past the internal detents. At this point move the arm towards the front of the car two positions or "clicks"
18. You are now ready to attach the cable to the transmission shift arm. Again before you do it, verify both the shifter and the transmission are in the neutral positions.
19. The new cable comes with an adjustable link at the transmission end. To make sure the cable is properly adjusted, there is adjustment "tab" on the end that must removed after you have snapped the transmission end of the cable onto the transmission shift arm.
20, Before removing the adjusting tab, once again verify both the shifter and the trans are in neutral !!
21. At this point you can remove the tab from the cable end link. (It just pops off with a screwdriver) then once if the tab is off, the adjustment securing lock is then pushed flush with the cable end link, this locks the end link in position with the cable and ensures proper adjustment.
22. With the car still jacked up, and nothing touching the rear wheels, I put the shifter into P and started the car up (Still no Exhaust) then moved the shifter thru each position to verify proper transmission adjustment. If all works as it should, then you can reassemble everything you removed in the earlier steps.
23. If it does not work as it should. (See step 14 above) Recheck the cable brackets, one end or both may not be fully seated or correctly positioned. (Remember this is a PITA) but it is critical to proper shifting of the transmission!) When you are certain all is working correctly, reassemble the rest of the parts you removed!

This is not something to be attempted by the faint of heart or if you'r not very mechanically inclined then by all means have it done by a professional !

On the other hand it only cost me $60 for the tow truck , $40.00 in parts and about 5 hrs of time to do the job in my garage.