4 speed shifter alignment

by Oliver Scholz

Three of our four Fieros have the 4 speed transaxle, and each of them had shifting problems from day one. All standard methods like shifter cable adjustment as described in the shop manuals, clutch or clutch pedal adjustments brought no notable change. On one of the cars it was impossible to shift into first without flashing the backup lights on. Adjustment of the backup switch was not possible, since the only adjustment that kept the backup lights off during shifting kept the backup lights off permanently. The 5-speeds don't have this problem, since the backup switch is mounted on the transmission on these cars.

This is when I realized that there must be a different way to adjust the shift cables. This method does not rely on inserting those adjustment pins into the shifter mechanism. The shift (forward/backward) cable is usually not the problem, but the select cable is. First I removed the backup switch and shifted the tranny into third gear. Now I loosened the nut on the select lever at the transmission. I tightened the nut again so that the shifter is at its right limit. Next I shifted into first gear. Now I loosened the 10mm bolt on the reverse inhibit roller on the shifter mechanism (don't remove it!). Then I moved the reverse inhibit bracket so that there is no more play and tightened the bolt again. Now there is a stop at each end to aid you in shifting, and both stops are now aligned with the transmission. Before, either 1-2 would shift right, but 3-4 wouldn't or vice versa. Finally I installed the backup switch again and adjusted the screw on its plunger so that the backup lights would come on only in reverse. This turned out to be no problem after this small adjustment that is not mentioned anywhere.

Another overlooked adjustment is the shifter shaft selective washer. If the 1-2 gear shifting is not smooth, and the cables are properly adjusted, this washer that helps position the shifter shaft may need to be replaced with a different thickness washer. The procedure is described in the shop manual, but the adjustment described above helped to make the car shift much more smoothly. This may or may not help you, adjust at your own risk. You can mark the old position of the reverse inhibit roller mechanism and always go back to your old setting if this adjustment doesn't work for you.

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