Differential, Torsen vs 3.15

[AZ_Ryan]

The window sticker lists the gear as an option with a cost but no actual code for the axle. Looking for the different factory codes on the door jam stickers for each of the installed axles.

For what purpose? 3.15s LSD are standard on non Performance Pack GTs. 3.55 LSD are an optional upgrade and will be on the window sticker.

Performance pack GTs have 3.73s torsen for manual, and 3.55s torsen for automatics.

Based on that, it's pretty easy to tell.

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[Tripower]

For what purpose? 3.15s LSD are standard on non Performance Pack GTs. 3.55 LSD are an optional upgrade and will be on the window sticker.

Performance pack GTs have 3.73s torsen for manual, and 3.55s torsen for automatics.

Based on that, it's pretty easy to tell.

What difference does it make for what purpose? Personal edification and future reference for others who might also be interested in such details. You're stating what we already know, what we don't know is what all the actual Ford axle codes are on the door jam stickers, and that is what my question was regarding, not what a window sticker says.

 

[rustedrotors]

I read somewhere the stock 3.15 were torsen diff when I was looking into buying my car. After having it for 22k miles I know its not.

My least favorite part on the car is the differential. Clutches are too stiff for my 235's. Feeling its a big reason the rear end come loose in turn too easily on these mustangs.

I went on this thread seeing if anyone has a preferred gear lube for the diffs. My plan when serving the diff was to reduce the action of the diff, or maybe just swap out carriers with a 8.8 open. Don't peel out, but take the turns hard with the car.

Far as carriers with high gear ratios go, typically there 2 types. To get low gears like 2.73, 3.08, and 3.15 the pinion gear is large. So they make a carrier where the ring gear is more away from the pinion, accommodating a larger pinion. With high gear ratios, the pinion is smaller. So they make carriers with the bolting face of the ring gear closer to the pinion. Usually, the highway gear carriers limit out at 3.73. Some manufactures of gears make thin ring gears or extra thick ring gears to make your carriers work on a higher range of gear ratios.

With 2 3 or 4 speed transmissions, gear ratio was really important. Some folks with a lot of hp need the ratio reasonable, so they don't run out engine rpms at high speed on straight aways on some larger tracks. For auto folks, getting the shifts programmed properly is a way better upgrade than changing the ring n pinon out.

Even in my old gto / transam days, I would modify the the clutch packs. Either take out a clutch section and add a etra steel to make up the difference in spacing, or take a torch and do the low rider thing to the clutch pack spring. Heat up a section of coil and let it expand.

Figuring out what I want to do with the newer style one. I might mill down the Zspring a little less wide, reducing the spring force. OR remove a clutch on one side or one on both and add steel to make up the space.

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