I have a guy who needs a vss gear from an isuzu, but I also have ones laying around from muncie 4 speeds - are they interchangeable, or does he definately need one from an isuzu?

thanks.

well, my auto th125 & my muncie 4 speed used the same VSS & gear - so, based on that - I would say yes
but - I dont know for a fact

If the gears have the same number of teeth on them, they are interchangeable. If not, you can still use the gear, but the speedometer will be off.

does anyone have a vss gear from an isuzu they can count the gears on?

The plastic gears are all color-coded for the number of teeth. There is a cross reference table in the Fiero illustrated parts book I have that I can scan and post later this afternoon. It states every year, tire, transaxle combination, and gear color/number of gear teeth you should have in order to maintain speedo calibration. Stay tuned.

I dont mean to hijack but I also have ?'s on VSS gears...

My 86 has a isuzu 5sp mated to it & the speedo is 15 mph off (too fast). I'm wondering if I just need to change the VSS gear. I'm guessing that the previous owner used the VSS from the original trans.

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86 GT
87 coupe restoration project.

As promised, here are the speedo gear charts for all years. Start further below by selecting the right year chart for your car. Then look at the lower half of the applicable chart and look up which tires you have. Then detemine which transmission and axle ratio you have (use this list if you're unsure):

1984
MD9 = 3 spd auto 3.18:1
MY8 = 4 spd man 3.32:1 (Coupe)
M19 = 4 spd man 4.10:1 (Sport Coupe)

1985
MD9 = 3 spd auto 3.18:1
MT2 = 5 spd man 3.35:1 (2.5L / Isuzu)
MY7 4 spd 3.65:1 (2.8L / Muncie)

1986
MD9 = 3 spd auto 3.18:1 (2.5L) or 3.33:1 (2.8L)
M17 = 4 spd man 3.65:1 (2.8L SE / Muncie)
MT2 = 5 spd man 3.35:1 (2.5L / Isuzu)

1987
MD9 = 3 spd auto 3.33:1 (2.8L) or 2.84:1 (2.5L)
MG2 5 spd man 3.61:1 (2.8L / Getrag)
MT2 5 spd man 3.35:1 (2.5L / Isuzu)

1988
MD9 = 3 spd auto 3.33:1 (2.8L) or 2.84:1 (2.5L)
MG2 5 spd man 3.61:1 (2.8L / Getrag)
MT2 5 spd man 3.35:1 (2.5L / Isuzu)

Then, see which "DRIVEN GEAR" letter applies in the second to last column of the lower part of the chart. Go to the top of the chart and look up that letter code under "DRIVEN GEAR" and you'll see the part number, number of teeth, and color of the gear that you should use to maintain speedo calibration, providing you haven't swapped out any of the parts with parts from other years, of course.

quote Originally posted by nmw75: I dont mean to hijack but I also have ?'s on VSS gears... My 86 has a isuzu 5sp mated to it & the speedo is 15 mph off (too fast). I'm wondering if I just need to change the VSS gear. I'm guessing that the previous owner used the VSS from the original trans.

alwasy 15 off, or at what speed is it 15 off?

It seems to be off at the higher speeds. 45-55 speeds.