Laycock J Type Overdrive Free OD YouI did fit them once I found that out (from this forum) them but they still seem to leak so maybe to get a leak free OD you need the copper washers *and* the breather clear.851-265. Over a period of 40 years, Laycock Engineering manufactured over three and a half million Overdrive Units, and over one million of these were fitted to Volvo motorcars.Just for general information for anybody searching OD leaks, a really common cause is that some of the studs that hold the overdrive together go through to the inside where the oil is. The Life and Work of ThOMAS LAYCOCK 1812-1876 Frederick.The J type Overdrive was introduced in the early 1970s, and was adapted to fit Volvo, Triumph, Vauxhall Opel, American Motors and Chrysler motorcars and Ford Transit vans.

V8 Register MG Car Club Section Fc, MGB Workshop Manual AKD3259 (15th Edition).