When I lock my hubs in I have a terrible grinding noise coming from the front diff only when I let off the gas. When I get back in the gas the noise stops. It sounds like gears not matching up or a hub that is not fully engaged. I have replaced the hubs with new Warn standards so I know they are not the problem. Last night I pulled the cover and rechecked the pattern and backlash and all looks good. I talked to tractech and they said it cannot be the Detroit check the Pinion bearings. So pulled the driveshaft off and there is no play in the yoke at all. So I took it for another drive, with the hubs locked in and in 4-Hi, going in a straight line about 35mph when I let off the gas it grinds like hell, now while coasting if I swerve back and forth the grinding stops like the Detroit unlocks, but when the wheels straighten back out it grinds again. So now I unlock the hubs but keep it in 4-Hi and it still grinds, and if I swerve back and forth it does not stop like it did when the hubs were locked. I think the Detroit is bad. What else could it be?? /forums/images/graemlins/1zhelp.gif Sorry for the long post but this has got me baffled.