expavr
Well-known member
In response to questions about the design and function of the shift tower on a 49 merc trans an early (1940) Ford 4 Speed Truck Shift Tower was modified to make the side shift 49 Merc O/D trans function as if it were a toploader transmission. The attached photos (1-5) show how it translates the horizontal movement of the shifter into a rotational movement of the shift arms on the transmission.
1.Brackets that mount on the bellhousing and tailshaft of the trans to support the shift tower.
2.The shift tower has two fingers that are attached to the shift plates on the shift tower.
3.The shift plates are attached to the shift blocks which are attached to the 2 movable (fore and aft) outboard shafts. The center shaft is pinned with set screws and used to stabilize the shift blocks to prevent them from rotating around the axis of the sliding shafts.
4.The tip of the truck shifter fits into a notch cut into the top of the shift blocks and it operates in the standard "H" pattern.
5. The fingers on the shift tower engage the shift arms which are mounted on the Merc transmission shafts that engage the yokes in the transmission. 2 pre-lubed bearings are used between the fingers and the shift arms to prevent binding as the shift arms rotate.
6. The finished look in the cab of the truck.
7. The finished look in the chassis.
Necessity is the mother of invention and after struggling with a Hurst shifter which didn't perform or look right I talked a friend, who is a superb machinist and has access to all sorts of tooling, into help building this contraption. To give credit where credit is due this project wouldn't have gotten off the ground without his expertise. Its been in use for over 6 years with 6,800 miles on it and has performed fine. For maintenance I blow out the cavity between the trans and shift tower and lube the moving parts once a year.
Les Williams
1.Brackets that mount on the bellhousing and tailshaft of the trans to support the shift tower.
2.The shift tower has two fingers that are attached to the shift plates on the shift tower.
3.The shift plates are attached to the shift blocks which are attached to the 2 movable (fore and aft) outboard shafts. The center shaft is pinned with set screws and used to stabilize the shift blocks to prevent them from rotating around the axis of the sliding shafts.
4.The tip of the truck shifter fits into a notch cut into the top of the shift blocks and it operates in the standard "H" pattern.
5. The fingers on the shift tower engage the shift arms which are mounted on the Merc transmission shafts that engage the yokes in the transmission. 2 pre-lubed bearings are used between the fingers and the shift arms to prevent binding as the shift arms rotate.
6. The finished look in the cab of the truck.
7. The finished look in the chassis.
Necessity is the mother of invention and after struggling with a Hurst shifter which didn't perform or look right I talked a friend, who is a superb machinist and has access to all sorts of tooling, into help building this contraption. To give credit where credit is due this project wouldn't have gotten off the ground without his expertise. Its been in use for over 6 years with 6,800 miles on it and has performed fine. For maintenance I blow out the cavity between the trans and shift tower and lube the moving parts once a year.
Les Williams
