More insight regarding those overdrive transmissions

March 1, 2011 | By Richard Prince

Question:

A few clarifications should be added to your reply to Paul Novacek in the November issue. (He wanted to know if Ford had a three-speed overdrive manual transmission in 1959 and if it would bolt up to his 428 engine.)

First, he should be very careful which overdrive transmission he uses. Ford used several different models over the years, and two different bell housing bolt patterns (1949-64 and 1965 through the mid-1980s). There were three main models of these; a light-duty version only used in the lighter-bodied six-cylinder cars, a medium-duty model used in the heavier cars and any application with a V-8, and a heavy-duty version that was used behind the “high-performance” motors, starting in 1960, I believe. This latter unit could be had as an option until the late 1960s.

The light-duty version is completely unsuitable for use behind a powerful, high-torque motor like his 428, and even the medium-duty version will be marginal at best. The inability of these transmissions to take the ever-increasing power outputs was one of the main reasons they lost popularity at Ford. Transmission failures were common with even the slightest abuse. Ford refused to install an overdrive behind the 428, limiting maximum engine size mated with an overdrive to a 390.

An original overdrive from 1959 will be either a lightor medium-duty model. Mr. Novacek will want to find a heavyduty version, but these are extremely rare. Most of the heavy-duty versions were installed in 1960s 1⁄2-ton pickups and have a short tail shaft with no slip joint, complicating a swap into a car.

Both the medium-duty and heavy-duty models can be identified by their “top loader” cases, with the heavy-duty model having a 4-pinion planetary overdrive unit in contrast to the 3-pinion overdrive in the lighter units. If he does find one, no adaptor should be needed.

The FE motor series (332 through 428 cid) has both bolt pattern bell housings available, so he need only find one that

matches his transmission. A matching year starter motor may also be needed. He should also be aware that some additional wiring is needed. A 12-volt supply to the solenoid and governor, a kick-down switch, and relay/ignition interrupter will be needed.