I have a ’04 LB7 with 2300 miles on it. I have a slight engine vibration right at 1100 rpm. At engine speeds below or above 1100 rpm there is no vibration. As the engine warms up, the vibration seems to diminish, but never completely goes away. This is not engine misfire and it is there in neutral or in gear, so it shouldn't be Allison related. What seems strange to me is that the vibration abruptly cuts off at engine speeds of 1200 rpms and higher and at 1000 rpms and lower. I can live with it unless anyone suggests that there may be a more serious mechanical problem developing.

Does anyone else have a similar engine vibration? Edited by: Dura_Mike

does it smoke at all?

There is no smoke at all. Fuel consumption seems normal at 14 mpg (all city stop and go).