Oldmech56

Had this very same problem with my Herald, turned out to be the new overdrive mount ...plus the new engine mounts that I had fitted., replaced the new engine mounts with second hand but much softer engine mounts and the noise reduced considerably , but was still uncomfortably loud. purchased a new overdrive mount from a reputable dealer.......no improvement, it was as hard as the first one . purchased two 8mm x 30mm cotton reel rubber mountings , made my own mount for the overdrive box and hey presto.....my Herald is now quiet, comfortable and drone free !!! I had struggled to drive more than a few miles up to now, as the transmission noise was unbearable.