So I finished up with the D1 CDL shifter install. After getting everything put back together, I moved the shifter, with the truck in neutral, to test out the linkage. Everything moved smoothly so I took it for a drive, in high/unlocked. I noticed that at about 25-30 MPH, under acceleration, I could hear a faint rotational noise coming from the transfer case/tranny area. At a stoplight, the idle felt rough under the seat. So I dropped it into neutral to make sure I was still in high/unlocked...I was. It wasn't doing this until after I engaged/disengaged the CDL for the first time after the install. The tranny and T/C were both serviced about 850 miles ago with new fluids and a new filter for the tranny. Other than the faint noise and a slightly rough idle under the seat it is running fine. Any ideas what might be going on?

 

did you figure out what the problem was? Mine is the exactly the same thing as your after I install a shifter in.

 

Normal when using a D1 shifter. You might consider removing the tunnel plate again and use a piece of heavy inner tube rubber to cover the entire opening then reinstall the plate.

 

Thanks,

I also notice that only after been driving for 30+ mins.