I have an Athern deisel that has a problem. When it takes right turns it is fine, but when it goes left it sounds like its gears are grinding or something, it is a very obnoxious noise. Someone once told me that it could be my radius. It is a large engine, and I am running it on an 18" radius, but I was wondering if maybe some oil or something might help. I have no idea what to do, any help would be great. Thanks.