RE: Overdrive Transmission

[steve375]

Is there such a  thing as an overdrive transmission kit that serves as an aftermarket for a Henry J does not have overdrive transmission as standard equipment? If so, where would I find one to purchase? How difficult is it to install? Thanks.
Steve

[kaiserfrazerlibrary]

What people generally do is find a donor overdrive transmission assembly (gearbox with the overdrive) and the drive shaft.  The transmision and overdrive unit are checked over and serviced or repaired as required and then the unit is installed in the car.  Bolt pattern for the flywheel is identical and the rear axle end of the overdrive's drive shaft matches.  The various electrical components mounted on the firewall and other places (such as the relay) get installed and properly wired.  An overdrive control assembly (with mounting bracket) comes out of a parts car as well and goes into the vehicle.

Consult the transmission, overdrive and electrical sections of the 1951-53 HJ Shop Manual that Kaiser-Frazer put out for more information, diagrams and other details.

[Fid]

Here's the whole overdrive transmission if you want -

http://www.ebay.com/itm/1950-WILLYS-3-SPEED-OVERDRIVE-TRANSMISSION-T-96-/251287826369?pt=Vintage_Car_Truck_Parts_Accessories&hash=item3a81ebefc1&vxp=mtr

You may have to replace the companion flange, and the two side levers with those from your current transmission but it will work. You would also need to get the correct drive shaft or have your current drive shaft shortened as the overdrive adds 18" to the unit.  You would also need a relay, kickdown switch (which can usually be obtained from a club vendor), associated wiring and a control cable.
The non-overdrive Henry J 6 cylinder cars have a different rear end than those with overdrive but if you're adding overdrive that is not that important - going the other way (removing overdrive) then it is.