I've had my non overdrive 150 for many years and always wondered about fitting an overdrive. I've just seen the following advertised locally and wonder what, if any differences there are in the gearbox between the advertised 140 and my late model 150. Also and very importantly what changes would I need to make to my car to fit the overdrive 'box - cross member, tunnel etc?

A fully rebuilt JAGUAR XK140 OR MK VII MOSS GEARBOX AND OVERDRIVE.
Gearbox and overdrive have new bearings, seals etc. and any worn parts replaced. Correct speedo and rear mounting. Sold with warranty, no exchange required.

Any advice appreciated.

Geoff

 

According to my copy of Paul Skilleter's encyclopaedic book "Jaguar Sports Cars", the XK150 transmission followed the same pattern as the XK140, namely a Moss gearbox, and overdrive or automatic option. Really the only significant differences apart from the rather bulbous body style, was the introduction of disc brakes, and a revised cylinder head, (the B type) for the Special Equipment variants.

So the gearbox you mention should be a straight swap except that the addition of the overdrive unit means a shorter propshaft is needed, or you have to shorten it yourself. Clearly this is a job for a workshops skilled in such matters. In addition, the overdrive cars had a different diff ratio of 4.09 instead of 3.54

The last change to production was quite late and this was the introduction of the 3.8 litre engine to replace the 3.4. However, Skilleter mentions no other changes on late production cars.

 

Thanks Fraser, I've now purchased the overdrive gearbox so installing will be a winter project. Summer here so a time to drive the car, rather than take it to pieces!


Geoff