[khpaladin]

We got our 'NellyBelle' (DW named her) in '98. She is an '81, 40ft coach, with a 6V92TA pre-DDEC, w/335hp (we were told, I'm not sure), w/ an Allison MT654CR 5-speed auto, and a Rockwell 3.70:1 rear axle ratio. We had a reputable shop do an in-frame on the engine, overhaul the tranny and differential, and do a mated dyno on the drive train. We have a GVWR of 35200, but are running about 31400, and pulling an '86 Honda Accord.

Initial start-up gives a small amount of white smoke and then runs clear at idle. All fluids are good with color and levels. I was told to keep the engine oil level about a quart low to minimize 'slobber' tube flow. This seems to work well and does not change oil pressure or temperature levels. Though we can run 75+ on the flat, we run 65 at about 1900rpm for fuel economy, and no exhaust trail. We get good takeoff from a standing start with a small puff of dark smoke, easy merging on the flat. When hitting small hills we start to loose power, and on 6% plus grades we can go down to 35-40 mph at about 2100-2200rpm with clear exhaust. On the flat we get around 11mpg, on hills we get around 5-6mpg, and overall average about 7-8mpg.

Since I have no background in diesel engines, I rely on others for diesel information and performance, and am not sure what the correct question should be. I've been told that this drive train should perform a lot better on hills, so I'm not sure it's suppose to loose that much power. I've been told to adjust my turbo boost, which I don't understand what that is, and don't think I have it. Just wondering if other coaches with similar drive trains are having this problem or is it just the nature of the beast and we live with it.

Best Regards