Allison Speedometer Diag Tips 

I had a last gen colorado with a 4wd unavailable message. After hours of tracing found a bad wire on the passenger side of the engine next to the exhaust. Shipped the truck and it came back with the same problem a few days later. Fought with it for a while until out of desperation i unplugged the aftermarket brake controller. Problem immediately went away. Plugged the controller back in and the 4wd unavailable message came right back. Got to love it when you find a problem but its not the main problem lol

That's a rare truck. Also, there is a company that makes replacement parts. For the quadrant stair. Company is called good systems.

Have you seen any tahoes or any GM? C theaters from 07 to 09. What's the rare interior color mccocoa brown inserts?And ebony outsorts