Quote:
Originally Posted by BAT
So the million dollar question is how do I tell what I actually have it I can not rely on the tag? I actually have 3 of these in the shop and sure would be nice to know what they really are.
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Here is what I did - quick and easy and probably accurate enough to help decide what the 1st and OD gears are.
1. With the tranny out of the vehicle, shift it into 5th gear.
2. Place tape on the input and output shaft and mark each shaft with a line at the 12 o'clock position.
3. Hand turn the output shaft (tailshaft) exactly one turn.
4. Look to see how far the input shaft turned. If more than 3/4 turn then the OD gear is 0.86 (although 0.78 is also possible in a Ford tranny), very very close to 3/4 turn would be the 0.72 OD gear. A 0.63 OD would be midway between 1/2 and 3/4 turns.
5. Do the same procedure with the shifter in 1st gear, but you must keep a closer eye on the input shaft so you don't miss a turn. You can improve accuracy in calculating 1st gear by turning the tailshaft 10 complete revolutions, and then dividing the input shaft revolutions by a factor of 10. i.e. 10 tailshaft turns caused 40 input shaft turns, so 40/10= 4, so you have a 4.03 1st gear.
I told a tranny shop what the tooth count was on the input shaft gear and a few other gears, and he told me what I had by doing some math. Sorry, but I don't know what his method was.