Ford 3 speed manual transmission

[gbritnell]

Gentlemen,
Years back I had built a Borg-Warner T-5 transmission to go behind my 302 V-8 engine. Back over the winter I thought about making one for my recently completed Fordillac V-8 engine. My son has a friend who's into all things flathead so he loaned me an early 50's Ford 3 speed trans to measure. I didn't take the whole thing apart but far enough to measure the gears inside. With the preliminary sketches made I competed a set of Autocad drawings and started making chips.
When I built the T-5 trans I opted to make it with spur gears because of several reasons but for this one I thought I would go all out and make the appropriate helical gears for it. The case, tailshaft and covers are made from 6061 aluminum while the gears and shafts are made from steel. The shafts are W-1 drill rod and the gears are 1144 grade steel.
The reason I didn't make helical gears for the T5 was because you have to make helical templates for each gear you cut and I didn't want to spend that much time.
With the math for the gears calculated I cut all the gears and to my surprise and delight they meshed well with a minimum of clearance.

 

[gbritnell]

The shift quadrants were made of steel and are indexed by small bearings in the side case. The balls are held apart by a spring. When the quadrant is turned the ball fits into the half round notch and holds the lever in place.

 

[gbritnell]

The spline shaft and bushing stock was purchased from Stock Drive Products out of New York. The bushing stock was large enough in diameter that I was able to machine the shift collar from it. without having to fabricate it. These can be seen in the gear pictures.
The main case was a practice in machining as there were a number of radii that needed to be cut and blended. The area over the countershaft has a conical bulge to it and it had to blend with the radii of the main shape of the case. I had to make adapter plates to mount the case on so that it could be put in the dividing head for machining.

 

[Cadillac]

Let me get this straight. You built a entire 3-speed transmission. Everything! That’s pretty spectacular, awesome job!

 

[gbritnell]

With all the machining complete I spent hours with small burrs, mounted stones and various files to finish the case.

 

[Mini Cooper S]

That is spectacular! Great job.

 

[gbritnell]

The tailshaft posed it's own problems. There was no way to machine it from one piece, that it the tailshaft and the rear mount so the tailshaft had to be turned, milled and finished before the rear mount could be attached. The mount was machined leaving extra stock on the radius that fits up against the tailshaft. I milled a slot in the tailshaft housing where the mount would go and slowly worked the radius down until it fir almost perfectly.

 

[gbritnell]

Here are some pictures of the finished transmission.

 

[Mtnmac]

Nice work... Any pictures of the gear cutting setup? I’ve made a few gears in my time, but never helical gears.

 

[gbritnell]

With the trans complete it needed some way to shift it. In the hot rodding days, at least my days in the late 50's and 60's, there were a lot of guys converting their column mount shifters to floor shifters. In the day there were many companies making shifters, the most notable and still in business is Hurst. I borrowed an old 3 speed shifter from a fellow hot rodder and made drawings of it. After making and fitting it I found that the original levers on the trans were too long so I had to make shorter ones otherwise the shift lever would over-travel and pop out of position.