Gearboxes

Z

zedhead260

Well-Known Forum User
I was wondering if anyone had any infomation on external gearbox identification. As far as I am aware, there must be at least 6 different boxes across the Z range (up to 280ZX). As a lot of Zed's get modified and played around with it would be interesting to research this so we all know what we are looking at (with regard to ratios etc).
I have a couple of old 260Z boxes kicking around from late cars, and will post my findings as soon as I check them out. <img src="http://www.zclub.net/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>
 
Z and ZX gearboxes have ID numbers, but hese are not embossed/printed on the boxes like the cylinder heads (E88, N42, P90 etc.) as far as I am aware. The casting numbers may mean something, and a little bit of collaborative reseach by members may well show a pattern that I'm not aware of!
The five speed UK boxes are designated FS5C71A for the 240Z up to Dec 1971 (the easily identified "straight-stick box), FS5C71B for 240Z/260Z from Jan 1972 and FS5W71B for all 280ZX boxes. The latter number appears to apply throughout the 280ZX run, but some mods to gear lever pivot point and ratios to suit the later 3.9:1 differential were introduced. All 280ZX boxes have the baulk ring style synchros, unlike the Z boxes which struggle along with the weaker and high wear cast iron, split-ring style synchroniser. The later 280ZX boxes seem to have a subjectively better feel to them, which leads one to believe that other components were refined as the years passed.

A survey of gearbox markings is a great idea, although bear in mind that over a 33 year time span, a lot of box swapping will have gone on, as all these boxes are physically interchangeable (more or less...). Go to it anoraks of the world.
 
I have just checked my 2 boxes. There appears to be four distinguishing marks.
1- inside the clutch housing at the base of the spindle.
2- by the reverse light input.
3- on the gear caseing.
4- on the left of the selector.
The readings are as follows - box 1 / box 2
1- S3E519 / 7107
2- L3 / L6
3- #2.5.19 / #10.2.22
4- 37 / 40
Both of these boxes came out of late 260's so I was hoping for some good results, but as you can see this is not looking good for starters. But they could be different boxes, which of course is the whole point to this.
I wish I'd noted these makings before I fitted my late 280ZX box. But then these boxes are easy to identify due to the gear lever bushing. I do have one more box to check but it is at a mates house and it will be a while before I get a chance to look. <img src="http://www.zclub.net/iB_html/non-cgi/emoticons/mad.gif" border="0" valign="absmiddle" alt=':angry:'>
 
00r28f14_sm.jpg

 
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 NISMO Close Ratio Competition 5 Speed  

Mike and all,

This topic comes up often, but so far there does not seem to be very extensive documentation on on the internet, to my knowledge.

I  believe Carl Beck, of the IZCC, has been working on some sort of documentation.  You might look around the IZCC website at www.zhome.com

I have almost every transmission type ever made for the early Z cars in storage and have thought of photo documenting them all, but I have so many projects stacked up so far that my effort will have to wait.

However, I have begun documentation on all the many clutch and transmission parts involved in a transmission transplant into a non-original Z car model. You can get some idea of how i am going about my photo documentation of these subjects by checking out Throw-out bearings comparison page.

Feed back, suggestions and comments welcome. 

Eric Neyerlin - owner of ZPARTS.COM
eric@zparts.com
 
The model designations of the gearboxes works as follows:
FS - floor shift
5 - 5 speed (4 - 4 speed)
C/W - close/wide ratio
71 - gearbox model (not sure about specifics)
A/B/C - gearbox 'series'

I use series as a generic term, the A series boxes have the porsche synchros & the 'monkey-motion/stirring-pot' shift (I know there's a gear here somewhere...) The 'B' series have the Borg-Warner synchros & the imporved shift mechanism (as shown in the ZPARTS photo). The C series is the model seen in the R31 onwards Skylines (and other 4/6cyl Nissans). I do not know if the Z32 gearbox is a member of this family or not.

Bear in mind that there are long & short extension housings for both the 5 speed 'B' series boxes. There are also the 'smooth-casing' models as seen in the A10 Stanza/Violet. Incidentaly these are also 'upside-down' gearshift models, as per the 'Option' boxes (option 1/2/3 etc). You can also change over the bellhousing on the 'short' 5-speed (as per R30 Skyline) with that of a 'C' series from the 'CA' model of engines to get a short 5-speed for that CA18DET conversion in your Datsun 1200...

Sorry a digression to a pet potential project  <img src="http://www.zclub.net/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=':p'>
 
Did we ever find out if there was a way to identify a gear box sensibly? I want to know exactly what I have, I may have to take it to pieces I think.
 
Wow, you pulled this old thread out of the darkest realms ! It was one of my first posts.

There is another stamping on the top of the clutch housing, usually difficult to read due to corrosion but i noticed it when cleaning my late 280 box up. Thought this could be something, but currently don't have any gearboxes lying around to check.
 
I have tidied the poll up now, bizarre.

I'll climb all over my gearbox tonight see if I can spot anything.
 
I guess there is still no conclusion as to how to identify a box properly? I will be getting a 280ZX box soon and I don't know what year 280ZX it came from. Is there any way to telling if it's the later box which has a better 2nd to 3rd ratio? Or would I have to go to the trouble of fitting it and finding out?
 
I have pulled two late ZX boxes and they both have a totally different stick arrangement to the earlier ZX box. Don't know if they have a different pivot position because I don't now have an earlier one to compare them with but I'll take a measurement if that will help.
 
Pics of the early and late 280zx sticks and one of the late pivot position. I'm told that with the late box and stick there is no requirement to make any adjustments to the gearstick aperture unlike the early one. Don't know myself because I hav'nt tried it yet.
 

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Late 280ZX boxes are the easiest to identify because of the shape of the casing (as well as the differences in gear lever).
 
Am I imagining thinks Nigel or did you post up a picture of the rear of an early 280ZX box (1 ear)? Where has it gone?

Well I've checked mine and it has one ear so it is an early box (as I thought) but I didn't have to alter the aperture for the lever.
 
The aperture of the for the lever doesn't need altering. On the later box, the lever needs to be bent into shape, otherwise you will not be able to select 1st, 3rd & 5th once the console is fitted (you may also find yourself punching the dashboard).

I don't know if these issues are the same with the early box.
 
Ok checked my box last night, it has one "ear" is this not a later model box as pointed out by Nigel?
 
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