To get back on point here...If you have a mid close or ultra close "A" box that you are looking to sell I am looking for them for my racing Roadster.

These would be the steel syncro "A" box transmissions (with either the long or short tailshafts). IF you have these transmissions and you want them to go to a good home where they will be used in a race car please contact me.

Thanks,

Ron

Ultra-Close Ratio: Part Number = MMCRK-32011

1st-1.858, 2nd-1.383, 3rd-1.217, 4th-1.00, 5h-0.852

Typos?

My copy of the Datsun Competition USA parts manual ( I think this is the second version ) lists:

'NMCRK-32011' and 2nd gear ratio as 1.388.

Option 3

1st - 2.554, 2nd - 1.758, 3rd - 1.271, 4th - 1.00, 5th - 0.850, Rev - 2.922

I can't find anything on this end that matches that gearing.

See the scan from the 'Nissan Sport Service' ( Japan ) transmission "bible" below:

Typos?

My copy of the Datsun Competition USA parts manual ( I think this is the second version ) lists:

'NMCRK-32011' and 2nd gear ratio as 1.388.

Hi Alan (everyone)

1 out of 2

Yes - NMCRK-32011 is correct (my typo)

No - 2nd gear is listed as 1.383 in the 73 & 74 Edition of the Datsun Competition Parts Catalogs.

See the scan from the 'Nissan Sport Service' ( Japan ) transmission "bible" below:

Very interesting... thanks.

FWIW,

Carl B.

On the transmission issue......what year 5 spd will fit in my 77 with a 4spd. I have heard all the way to 83. Any certain tranny to look for or any to stay away from?? Thanks

Hi Alan, Carl, infact everyone posting.....I just want to jump in and say thanks! for this thread. The info, and the way in which it is being imparted is the very essence of why this is such a great forum and site.

Thanks guys

Jim.

Hey while I'm at it, I've been told I have a ZX turbo gearbox (manual 5speed)

Any way to confirm this? That's all I've been told about the box, no model or year info, but of course I can check the 'box itself for clues.

Great stuff guys. I pulled my 5 speed out of my 12/70 build 240z last night. It is a A box and my guess is it has standard ratios.

There aren't any markings on it so how do I know what it is?

There aren't any markings on it so how do I know what it is?

James,

If it is the original FS5C71-A that came with the car from the Factory ( and who knows what might have happened over the car's 35-odd year life so far? ), then it should have the ratios on the far right of the chart below.

Of course, the only way you can be 100% certain of what ratios you have is to take the trans case apart and start counting teeth on gears ( not fun ).

Cheers,

Alan T.

No - 2nd gear is listed as 1.383 in the 73 & 74 Edition of the Datsun Competition Parts Catalogs.

Carl,

Take another peep at the chart I attached above. Notice that the 'Option 2' 2nd gear is listed as 1.388?

This is consistent in all of the Japanese literature that I have - ranging from 1970 right through to 1978 - through the factory Parts Lists, 'Sports Option' lists ( 14 issues ) and the 'Nissan Sport Service' issued tranny manuals and race tuning advice manuals, which give all the individual gear and counter-gear tooth counts and part numbers.

To be honest, I think I'd rather trust the information provided by the people that actually made the gears ( Nissan Japan ) over the people that sold them in the USA ( Datsun Competition USA ). But that's just me.

The difference is 0.005 between the two listings ( !! ). I think the Datsun Competition USA listing is just a simple typo.

Alan T.

Hey while I'm at it, I've been told I have a ZX turbo gearbox (manual 5speed)

Any way to confirm this? That's all I've been told about the box, no model or year info, but of course I can check the 'box itself for clues.

Hi Jim,

Thanks for the words of encouragement. I think this stuff is good fuel for the archives, to be found again in future using the SEARCH function.

As for your question, my personal take on this subject is ( as I replied to James ) that the only 100% sure way to know what you have is to start counting teeth on gears. You can try and work out the ratios by measuring the difference between input and output turns, but that always seems a bit hit-and-miss to me. Taking the case apart is not that difficult and it will also allow you to inspect the bearings, synchros and gears for wear.

I've seen transmissions with part numbers stamped into the top of the bellhousing, and also some with the part number printed in blue ink in the same position ( doesn't survive very well ). I've also seen them with no identification numbers or letters at all. Not very consistent, is it?

Cheers,

Alan T.

Hey while I'm at it, I've been told I have a ZX turbo gearbox (manual 5speed) Any way to confirm this? That's all I've been told about the box, no model or year info, but of course I can check the 'box itself for clues.

I don't know if this applies to Australian cars but in the US, the ZXT had the Borg Warner T5. Side by side they are noticeably different from any of the Nissan transmissions.

Hi Alan, Carl, infact everyone posting.....I just want to jump in and say thanks! for this thread. The info, and the way in which it is being imparted is the very essence of why this is such a great forum and site.

Thanks guys

Jim.

Hi Jim (everyone)

Thanks - always fun to share whatever I can.

Hey while I'm at it, I've been told I have a ZX turbo gearbox (manual 5speed)

Any way to confirm this? That's all I've been told about the box, no model or year info, but of course I can check the 'box itself for clues.

This should give you a good idea of what the Borg Warner T-5 looks like.

See <a href=http://zhome.com/ZCMnL/tech/BorgWarner.htm TARGET=NEW>http://zhome.com/ZCMnL/tech/BorgWarner.htm</a>

kind regards,

Carl B.

Clearwater, FL USA

http://ZHome.com

On the A box transmissions it is a case where you have to count teeth to be sure..So if you have an early A box and you are not sure what it is...you will need to split the case and start counting.