Hi all. Thanks for all your suggestions. I had another crawl under the zed and amazingly, the mechanic who fitted the new front insulator diff mount forgot to tighten up the nut in the centre which secures the mount. I've tightened it up and all the clunking when driving off and changing gears is gone. All back to normal. Obviously with the nut not done up properly, the mount was I gather letting the diff and shaft move up whenever torque was applied. I'm happy it was such a simple fix. Again, many thanks for all your suggestions. Cheers. Roy