Terrano (2002-2003 manual transmission) has developed a very bad shudder in recent days. Does not seem to be wheel or steering related and there is nor real shake or vibration in the steering wheel. Don't think it is suspension or gearbox/ engine mounts. Don't think it is drive shaft or u-joint. Problem has started at the same time as problem with transfer box lever coming loose. 4wd high and low are working (tested it in muddy grass) and 4wd light on dash going on and off as it should be. But because the two issues arose at the same time I'm thinking they may be related. Any ideas?