Do you need to change reluctor ring in rearend, if you change ratios

[badz409]

I want to change 3.23 gears to 3.43, do i need to change reluctor ring. also how do I get the speedo right.

[Gary94Formula]

If you have the 3 series carrier, you shouldn't have to replace the ring. You'll need to get the PCM re-programmed to fix your speedo..

[Injuneer]

You might want to mention the year of your car. Since you are asking about the ABS reluctor ring, I guess we can assume its a 4th Gen.... but why make people guess? If for example, its a 93, it affects how you correct the speedo. That would be different than the 94 and later cars.

[badz409]

3.23 gears to 3.43 is reluctor ring ok

I goofed, it is a 1995 Firebird Formula/ ABS & Traction Control

[Injuneer]

If you have traction control, you do not have a reluctor gear on the differential carrier, nor a sensor on top of the housing. With TCS there are individual rings pressed on the outer end of each axle, and a sensor on the backing plate. Those will not be afected by the gear ratio change.

For the 94+ cars the gear ratio change needs to be programmed into the PCM. A mailorder tuner can do it for you, and pick up a few HP while reprogramming. Or you could find a used Hypertech programmer - changing the gear ratios is one of the few things they are useful for. Or get programming software like TunerCat or LT1_Edit and a cable and program it yourself.

[01Z]

I want to change 3.23 gears to 3.43, do i need to change reluctor ring. also how do I get the speedo right.

The reluctor should be determined by your carrier. I know from experience that my 2 series Torsen has a much more narrow ring than the 3 series Auburn. I was afraid I would lose my ABS when swapping carriers so I tried to swap the reluctors. It wouldn't work but apparently the sensor is happy with the narrow reluctor that replaced the wide one.

Short story: if you aren't changing carriers then you have nothing to think about regarding the reluctor ring.