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Spare Diff delivered, question about casting

Zedyone_kenobi
Zedyone_kenobi
in Engine & Drivetrain

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Posted
comment_258433

I was cleaning off my diff I received from the Z store, and noticed that it had NO markings on the bottom of the diff. My stock Diff has two numbers cast into the bottom. One is T25, the other is something else, I need to go back and look. The light was bad.

The new diff does not have any stampings cast into it. Its just a curiosity, but I would hate it if my R180 is different from this R180. The gear ratio is about 3.5:1 ish. So thats correct for a 71 240Z 4spd car.

If somebody has time, take a look at the bottom of your 240Z Diff and let me know if it has any stampings?

I need a Z part interchange manual.


comment_258434
I was cleaning off my diff I received from the Z store, and noticed that it had NO markings on the bottom of the diff. My stock Diff has two numbers cast into the bottom. One is T25, the other is something else, I need to go back and look. The light was bad.

The new diff does not have any stampings cast into it. Its just a curiosity, but I would hate it if my R180 is different from this R180. The gear ratio is about 3.5:1 ish. So thats correct for a 71 240Z 4spd car.

If somebody has time, take a look at the bottom of your 240Z Diff and let me know if it has any stampings?

I need a Z part interchange manual.

I don't recall any casting numbers on the bottom of any of mine, but I don't know that I have ever looked either. I'll try to check on my spare unit, which came out of a 4/71 car.

BTW, a '71 4 speed would have come with a 3.36:1 ratio. A '71 automatic had a 3.54:1.

  • Author
comment_258438

Thanks for the correction, Arne. I just spun it around and counted...its 3.XX:1 something. But I will make note tonight and do it correctly!

comment_258472
Take the rear cover off and read the ratio stamping on the ring gear.

Actually, if you take the cover off you can just count the teeth on the gears. The 3.36 has 37 teeth on the ring gear and 11 on the spur gear (I think that is what it is called) The small one at the front of the housing.

The 3.54 has 39 and 11. If you are really lucky you will find 39 and 10, but don't get your hopes up... LOL

comment_258493
Actually, if you take the cover off you can just count the teeth on the gears. The 3.36 has 37 teeth on the ring gear and 11 on the spur gear (I think that is what it is called) The small one at the front of the housing.

The 3.54 has 39 and 11. If you are really lucky you will find 39 and 10, but don't get your hopes up... LOL

Why count them when the numbers are stamped right on the ring gear? It would say 37:11 or 39:11.

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