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5 speed id help


Stitebunny

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It's an FS5C71A.... very nice!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Oh yeah. When the '70 240z came out and was raced, it unfortunately had a poorly geared wide ratio 4 speed and no 5 speed at all. In fact, in N America there weren't any 5 speeds for the S30 until '77. In Europe (I believe) there was a 5 speed available and many found there way to N America. The FS5C71A is a Roadster 5 speed and has a removable bell housing. It was easy enough for Nissan to cast an L bell for it and convert for use on the Z car.

 

The synchronizers are Porsche steel servo type able to stand up to severe racing. Most transmissions are Warner type made of bronze.

 

Theses L series FS5C71As were quite rare then and even more so today. Racing is hard on cars and the transmissions in them. These vintage legal transmissions are in great demand by racers who want to keep racing their vintage cars. Most parts for them are cast from pure unobtanium.

 

The gearing is

 

1st.... 2.957

2nd... 1.858

3rd.... 1.311

4th.... 1.000

5th.... 0.852  Although there were two other Nismo Option boxes with Middle close ratio and Ultra close ratios.

 

The reverse lamp switch is #32005-21000 I don't know if it's still available. Was on the 510 3 speed standard and 240z 4 speeds but only to '72

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It's an FS5C71A.... very nice!

 

 

Oh yeah. When the '70 240z came out and was raced, it unfortunately had a poorly geared wide ratio 4 speed and no 5 speed at all. Strange, as the Fairlady Roadster before it did have a 5 speed box. In fact, in N America there weren't any 5 speeds for the S30 until '77. In Europe (I believe) there was a 5 speed available and many found there way to N America. The FS5C71A is an old Roadster 5 speed and has a removable bell housing. It was easy enough for Nissan to cast an L bell for it and convert for use on the Z car. Theses L series FS5C71Bs were quite rare then and even more so today.

 

The gearing is

 

1st.... 2.957

2nd... 1.858

3rd.... 1.311

4th.... 1.000

5th.... 0.852

 

Wow... It could possibly be a NISMO competition box???

 

That is the closest ratios you can get for a 510 gearbox without a custom gearset.   With 3.90 or 4.11's that should be a bit of fun. 

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Gears: 1.838, 1.388, 1.217, 1.0, 0.852

 

Can I assume this is in it?

 

 

The gearing is

 

1st.... 2.957

2nd... 1.858

3rd.... 1.311

4th.... 1.000

5th.... 0.852 

I believe the above is what came on the European S30 5 speed. (It may have been an option but this was what you got)

 

These were available from Nismo and were available for racing. 

The mid close ratio gears are...

1st.... 2.678

2nd... 1.704

3rd.... 1.262

4th.... 1.000

5th.... 0.852

 

The ultra close ratio gears are...

1st.... 1.858

2nd... 1.388

3rd.... 1.217

4th.... 1.000

5th.... 0.852

 

 

Stitebunny

It would be a bit of work but if you mark the driveshaft with chalk and raise the rear wheels off the ground and place in first gear. Then crank the motor over 10 times.

 

The drive shaft will turn ...

close ratio............... 3.38 times

mid close ratio........ 3.73 times

ultra close ratio....... 5.38 times

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Gotcha! 

Thank you!

 

So now that I know it's fairly rare, am I going to have a hard time finding a reverse light switch?!  Or might it share one with more common gearboxes?

 

Also I was just looking through a service manual I got with the car and the previous owner had hand written in some numbers to figure the top speed at 7,000 rpm based on the gearing of the "240z speed" with a given rear end ratio

 

He has gears:

 

1st 2.960

2nd 1.855

3rd 1.310

4th 1.000

5th .850

 

Possibly a rough estimate by calculating turns on the input shaft??

 

I guess next I'll see what rear end I have.  This is a wagon by the way.  And there was a spare rear end with the car also.

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Gotcha! 

Thank you!

 

So now that I know it's fairly rare, am I going to have a hard time finding a reverse light switch?!  Or might it share one with more common gearboxes?

 

Also I was just looking through a service manual I got with the car and the previous owner had hand written in some numbers to figure the top speed at 7,000 rpm based on the gearing of the "240z speed" with a given rear end ratio

 

He has gears:

 

1st 2.960

2nd 1.855

3rd 1.310

4th 1.000

5th .850

 

Possibly a rough estimate by calculating turns on the input shaft??

 

I guess next I'll see what rear end I have.  This is a wagon by the way.  And there was a spare rear end with the car also.

 

Reverse light looks like the same one as on my ZX box.  Should all be the same, I bought a new one for like $20.  The part number should be around these forums somewhere.

 

That's a nice gearbox, the shorter 5th is great for the track if you use it for that. 

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I am a little confused, how can you tell this is a rare roadster 5 speed from the common roadster 5 speed from the outside, I thought you had to look inside and check the synchros.

 

Wayno I believe all 71A Roadster 5 speeds had the C 'competition' steel synchros in them. The common one would probably be the close ratio with the two other Nismo less likely

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Wayno I believe all 71A Roadster 5 speeds had the C 'competition' steel synchros in them. The common one would probably be the close ratio with the two other Nismo less likely

 

How are you able to tell he has a rare one from the outside?

I agree he does have the hard to find "L" bellhousing, but other than that being rare, how can you tell this guys tranny is a comp. one?

 

I have this in my attic.

 

DSCN0832.jpg
 
DSCN0831.jpg
 
DSCN0830.jpg
 
DSCN0833.jpg
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I didn't remember (or realize, I guess I've only seen 'em apart) that the bellhousing bolts are on the INSIDE. 

 

Wayno's has very different casting ribs... like a Roadster one, I think.

 

One of the guys I know that rebuilds Roadster gearboxes has found either style synchos in the gearboxes. 

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Wayno that is a 4 or 5 speed? [edit]All 71B 5 speeds were C competition steel synchros AFAIK.

 

Look in the fill hole and look for brass. Here are pictures of steel synchro rings from a 71B tranny.

 

 

FS5C71Bsteelsynchroswideratiocompetition

 

FS5C71Bsteelsynchroswideratiocompetition

 

To compare...

 

FS5W71Bteardown006Large.jpg

 

synchroLarge.jpg

.

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As far as I know, most 71Bs had brass synchros. Any transmission with a "W" in the model code (FS5W71A) would be brass "Warner" type synchros.   An FS5C71A would have Servo-type (sometimes called Porsche type) synchros, which are the steel ring servo type.  They have a very different feel to them, but are VERY, VERY expensive to replace when they break.  Some people mistaken the "S" for Servo type Synchros... the S indicated overdrive.  Lack of an "S" means 1:1 top gear.

 

The US got 5-speeds as an option in the 2000 Roadster, but the 1600 only had the 4-speed as far as I know.  You could order a 5-speed conversion for a 240Z and 260Z from the dealer, but they weren't delivered as a factory option until the '77 model year.

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My 1867 roadster has a 1968 U20/5 speed in it, and I have this extra 5 speed in the attic, as far as I know, all the 2000cc roadsters came with 5 speeds.

The 4 speed/R16 that came in my roadster had a flat bottom removable plate, as it did not split apart in the middle like the 5 speeds.

I have always been lead to believe that you had to physically look at the synchros to know if you had a good one, as the transmissions are the same on the outside, but you started talking about how this guy has a competition gearbox by the photos, but maybe you know something I don't know that others that do know are not willing to tell me.

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