Hi All,
I have a 1972 142S with a standard 4 speed gearbox , I have been toying with the idea of switching to a 4 speed with overdrive, my questions are,

Is it worth it in terms of Fuel economy?

Is it that much easier on the engine because of reduced RPM's

So whats the general feeling among all you guys who have much more experiance than I do??
Cheers,
Dave

One thing nobody has mentioned yet is that the OD tranny is about 30 pounds heavier
than the M40 so if you don't have good upper body strength or other ways of lifting
and positioning it on installation, it can be tough going.
--
George Downs, Bartlesville, Heart of the USA!

It is definitely worth doing, especially if you do a lot of above 50 mph traveling. I would not put it above getting everything else running and functioning properly on your newfound interest, and I would also make sure that it has been looked at and serviced by a competent tranny mechanic before you install it. They aren't bad to install as long as you have all the correct parts that go with them. You'll find it is quite a bit quieter in the cabin with the OD at freeway speeds. Let us know how it works out.

It is a simple conversion. The rpms do drop. The motor is quieter. But.....

It is hard to get one that is functional, and stays functional. After 35 years the seals and o- rings need replacement on many J-types by now. I have two J-types I am edging towards rebuilds as they no longer can generate enough pressure to stay engaged. The OD is something else to add to a long list of problems to fix and repair on old cars.

Joel
--
Antique Swedish Steel 71 142E color V#102

It's a bolt-in.
Maybe slight change in fuel economy.
Engines rev OK but it is easier on the driver!
--
George Downs, Bartlesville, Heart of the USA!