LSD vs FZ Transmission, Speed Sensor Bung is Different. Any Options?
 

Hey All,

First time here everyone, working on a 09 SS Cobalt LNF that had a "LSD" labeled transmission that was also a replacement (not the original trans). Well it broke. I have a "hopefully" swapable trasmission to replace it. It is a "FZ" labeled trans from a Saturn Redline.

The problem: The LSD trans uses what appears to be a vehicle speed sensor. There is a bung for it. The FZ trans also has a bung in the same location however the bung is sealed. There is no opening at the bottom of bung. Or does the 09 SS not need this to be connected? I'm not sure if maybe it was unplugged before...

Have any of you ran into this? Any way to make it work properly? I'll follow with pics..., Thanks for the help

LSD stands for limited slip differential.

the transmission you have without the vehicle speed sensor will be from a 2004, they used a vss and reluctor wheel on the passenger side steady bearing, it was a 1 year only deal. all 2005 and newer f35 transmissions had the vss in the transmission. there is no way to make a 2004 ion redline transmission work in a 2005+ vehicle, its not as simple as running the ions steady bearing setup as the tooth counts are different.

you could use the ion transmission as a core, have those guts put into the case from your transmission, along with the limited slip diff (as the ion trans likely isnt a limited slip), but that is a lot of work to set up. your best bet would be to find a 2005+ transmission.

Thank you, Good to know. Glad I stopped at this point and confirmed.


Would swapping a portion of the transmission case from LSD to the FZ be a possibiliity? Or drill a hole to access the gear :nono: :) You mention the tooth counts were different...the gear that sends signal to the vss has different teeth counts? Not sure if the diff gear sends the signal to the vss on the LSD...


Is it harder to sell the FZ Ion 2004 transmissions due to the design? What are they worth? I can swap a trans case possibly but would rather had a straight forward swap like you mentioned...

the speed sensor picks up off a reluctor wheel on the diff, i do not believe the 04 ion transmission has that reluctor wheel, so its not as simple as drilling a hole.

as for swapping parts, its not an easy thing to do. you would have to use the case half that has the sensor in it, id use the limited slip diff that already has the reluctor wheel on it. you would obviously use the input and counter shafts from the ion trans, and would have to use the swap the ion ring gear onto the limited slip diff (supercharged cars had a 4.05 final drive, along with the hhr ss, where the ss/tc had a 3.82). doing all this would require properly shimming everything and isnt a simple process, and it does require some special tools. if you havent worked on a manual transmission, this isnt one to learn on.

hard to say what the 04 transmission is worth, kind of a small market, and they can use an 05+ transmission if they need (they just use their existing speed sensor on the axle).

Good advice Sharkey