In particular the gear ratio 8PZC, I know 8PCC is 3.33 but this?

Thanks, Jonathan

Remove the bolt, pull out the speedometer/speed sensor and look at the color of the gear. That will tell you the gear ratio. For instance it it is Blue the FDR is 3.33:1. The repair manual lists the gear colors and the ratios that the sender is set up to interface with.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

quote Originally posted by Dennis LaGrua: Remove the bolt, pull out the speedometer/speed sensor and look at the color of the gear. That will tell you the gear ratio. For instance it it is Blue the FDR is 3.33:1. The repair manual lists the gear colors and the ratios that the sender is set up to interface with.

Thank you for your help, is this considered Blue?

green gear was 29 teeth.
blue gear was 30 teeth.

who knows what color yours started out as....

MD9 TH125C Automatics will typically have the large GREEN 10 tooth drive gear. I believe that's for a 2.73 FDR
There are two smaller VSS speedo gear sizes.
BLUE 30 tooth - 3.33:1 FDR
WHITE 31 tooth - 3.331 FDR probably for smaller 14" tire sizes on the Duke cars.

Yours looks like the blue and you should have a 3.33:1 FDR trans.. Best ratio for pick-up / 1/4 mile but a bit worse for gas mileage.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Thanks guys, Igreatly appreciate the help.
Jonathan.

You a have a very late model 1988 Canadian made th125C with a 3.33 ratio manufactured on March 10 1988. It has two 35 tooth chain sprockets, heavy duty chain and clutches. It also has a three plate torque converter with the revised TCC solenoid (new design) to achieve lower rpms at highway speed while cruising, it probably came in a special order 88 Formula, the id tag originally had PZC in large letter across it. This is the best th125 that came in the Fiero but only the very last production cars got it.

[This message has been edited by Horse (edited 09-03-2015).]

You can barely read the PCZ on the label but it is still there, I got it in 1990 from a junkyard car with 9500 miles. I am hoping it is still good as mine went bad. This board is amazing.
Thank you all once more.
Jonathan