Hard shift/whistle/TC related?
I should state right off the bat that I am a red-seal certified partsman, trained in the automotive and now work for a Kenworth dealer, so I'm very well versed in all aspects how a truck is built and should perform, but my experience in that automotive stuff is getting further and further away as I get greyer. Ask me about parts for your Cummins and Cat engines and i'll pull that right out of my back pocket. However i have not owned an AT trans loaded vehicle in over 12 years, and it was a bullet proof C6 in my old Bronco.
Right off the bat when I picked up the truck up from new there is a whistle in the truck that comes on at about 50kph and stays till 65kph. When i manually downshift into 4th or below without changing my road speed the sound goes away. The local dealer has tried several times to find the source of the noise, the only fix they were able to attempt was a couple of pieces of weatherstriping on the door seals thinking maybe the noise was originating from there. They also tried their 'electronic ears' to no avail. Still whistling, waiting for catastrophic failure before the dealer will adress this again.
During a recent 2500km trip i noticed that when the truck is in cruise and has to gear down into 3rd gear for a hill, the trucks shifts quite hard into 4th coming back up. Has anyone else had this same issue?
And finally, having only glanced at the issues concerning the TC, I have no grinding only a whistling as far as 'odd' noises go.
Last edited by KWPartsGuy; 08-11-2012 at 02:29 PM.