I'm thinking of putting an overdrive in my '65 122. It has a stock tranny in it right now and, well, I want another gear. I'm getting sick of my screaming engine that's asking for another gear.

I've heard that you have to remodel the tranny tunnel to put in the short shifter overdrive. Is that true and is it easier to find an overdrive with the electric shifter on the steering column?
kpotter@cln.etc.bc.ca

Phil says: Yes, you would have to remodel the tunnel to fit the 1800-style remote shifter. However, you could also use your present top cover and shifter on the OD transmission, in which case no mods to the tunnel are necessary in an Amazon (not so the 444/544). All M41 transmissions used an electrically actuated OD, so you'll need a switch -- the "electric shifter" on the steering column is the most graceful solution if you can find one, but a toggle on the dash works too. Make sure you understand how the OD relay works before hooking this up. This is a common and most worthwhile mod -- good luck!

More from an enthusiast: The shift plate for an OD tranny is different on the 122. There is a relay in the OD top (123GT or OD equipped) that is not on the M40 top. This is to prevent engaging OD in any gear other than 4th. With the column mounted OD switches becoming scarce, I suggest using the shift plate out of the '75 240 series that has the switch in the knob. This of course if you do the floor as I did on my 122.
Jerry Sira
dnjsira@erols.com

Jim says: The transmission cover for an M41 from 140 models with the long shifter has provision for the lockout switch (as well as a backup light switch; choose the right hole). Many are found with a plug in the hole for the OD switch. Using this cover, you won't need to modify the tunnel.