Got it to pass smog, the work begins now... 1986 Nissan 720 project

[A guy named Rick]

I am going to determine if its a 4 or 5-speed tonight.

[datzenmike]

It's for the best

[A guy named Rick]

Just confirmed it is a 5-speed.

 

I have the ecu from that 280z (wasn't intending to convert it to efi. At least i wasn't yet at that time). Could I tell for sure what year the 280 was from that? I was told it was a '76, hell, I even saw the car. It was an old co-workers brother's car, he was planning on doing a V8 swap from an Infiniti M45. Sounded like a cool idea at the time. It could have maybe been a '77, and that would mean it was the original transmission.

Edited September 16, 2021 by A guy named Rick

[datzenmike]

August '76 and on build dates (usually on the driver's door jam tag) was the start of the '77 model year and the optional 5 speed.

 

Yes post any numbers on the control module.

 

Look for

22611-N4212 or A11-60000*  manual, federal and California emissions

22611-N4800 or A11-601000* automatic, federal and California emissions

 

* May not have the Nissan part number but should have this one from the electronics maker (JECS) on a foil label

[A guy named Rick]

I'll try checking tonight.

 

I'm pretty sure now that it's the original transmission, and from what i recall there wasn't too many miles. Pretty honest people i bought from. But now I'm thinking, would going wide ratio be better, especially for towing if i were ever to later down the line? Also acceleration too would be better? Or is it better with the mid ratio? Just wondering. I'll make do with what i have anyways.

If/when I extract the transmission from the 240z, would it potentially be easier just pulling the whole motor and transmission together, then separating? Not a whole lot is actually hooked up to the motor, and not even anything to the transmission except the driveline.

Edited September 17, 2021 by A guy named Rick

[datzenmike]

 

It's not a truck with welded in cross members in the way. It should just drop out under neath.

 

A wide ratio would have better torque for pull-a ways when loaded. Unless a working truck doing this every day, it's hard to see going to the bother.

 

Did you measure the length of your transmission?

[A guy named Rick]

Nah haven't got around to measuring either. Would it matter much anyways? I have to swap bellhousings since it would be going from an L to a Z.

[datzenmike]

Yes. The 720 had two different lengths. If you have the 26" shorty the z car 5 speed won't fit unless you find a shorter drive shaft. 

 

You know that the front case would also need to be swapped as well? The front case on the 720 box would need to go onto the Z car 5 speed to convert it for use with the Z24 engine.

[A guy named Rick]

42 minutes ago, datzenmike said:

Yes. The 720 had two different lengths. If you have the 26" shorty the z car 5 speed won't fit unless you find a shorter drive shaft. 

 

You know that the front case would also need to be swapped as well? The front case on the 720 box would need to go onto the Z car 5 speed to convert it for use with the Z24 engine.

I'm pretty sure i have the short one. When I had it out before, it seemed small.

I thought front case was the bellhousing. or, the entire case needs swapped? hey, whatever works. My Z isn't going anywhere anytime soon, and instead of rebuilding the one in the truck, I'm all for swapping parts. If this means the entire case, then that's what I'll do. i was thinking i would only have to swap over the front half of the case. I'm however not looking forward to the black widows that are undoubtedly under the Z.

[datzenmike]

The difference in lengh is in the rear part so the Z car one will be too long to fit.  It's 31.5" long, the shorty, if that's what you have, is 26".

[A guy named Rick]

I will have to measure then

[Charlie69]

You can shorten the front drive shaft and mod the rear transmission bracket to make the longer transmission work.

[A guy named Rick]

On 4/29/2019 at 1:26 PM, datzenmike said:

'85 to '86.5 720 and S12 (200sx) 71Bs had the larger 62mm bearing and cover plate. '86.5 and on the 71C was used and they all were 62mm. Any 71C cover plate will work if you machine out to 62mm for the counter bearing.

 

Check the gear oil every year and replace every 30K

 

👆 Also this too would pose an issue wouldn't it? ☝️ I may as well just rebuild what's in the truck 😔

[datzenmike]

IF you were to swap the earlier L series case on just pull the 62mm bearing and slip the 56mm one on.

[A guy named Rick]

I would be pulling the L series to swap the Z series case onto. But same concept, except knowing the Z series needs attention i would probably just get a new 62mm bearing to be safe.

Edited September 18, 2021 by A guy named Rick

[datzenmike]

What about the length????

[A guy named Rick]

sorry, just edited previous post. i was just saying if i were to do that. i haven't measured yet, i need to, just busy with work. i would of course do that before going through the trouble.

[A guy named Rick]

On 2/26/2016 at 7:49 AM, Phixius said:

I got some info for the 'C' type trans and comparison to longtail 5spd...

 

Tranny measurements. ..

Bell to dust shield..
S14 KA -- 33 1/2"
Longtail (L) 5spd -- 31 1/4"
Track KA/Z24 30 1/2"

Bell to output shafts
S14 KA -- 33 5/16"
Longtail 5spd (L) -- 31 1/2"
Truck KA/Z24 -- 29 15/16"

Shifter hole location
S14 KA -- 31 1/2"
Longtail 5spd (L) -- 29"
Truck KA/Z24 -- 26"

 

pictures.

 

http://i642.photobucket.com/albums/uu142/phixius/20160215_183726_zpsw8kygtav.jpg

http://i642.photobucket.com/albums/uu142/phixius/20160215_183741_zpss4az94xl.jpg

http://i642.photobucket.com/albums/uu142/phixius/20160215_174945_zpslvsladqm.jpg

If my memory serves me, the middle transmission looks like mine that's in the truck.

Edited September 18, 2021 by A guy named Rick

[datzenmike]

You have a 71B. Those are 71C transmissions.

[A guy named Rick]

oh. yeah. totally missed that.

Wait. do i have a 71B? 1986 720. Did they have a 71C also used?

Edited September 18, 2021 by A guy named Rick

[datzenmike]

The 71B was used through the 720 till it's end in '86.5. The 71C was used on the next gen D21 Hardbody. The S12 which was produces from '84 through '88 also switched to the 71C from the 71B in '86.5. The only other RWD vehicle back then with the 71C was the new '84 300zx non turbo.

[bottomwatcher]

Depends on how you are going to use your truck. I used a couple 280Z trans in my 82 4x4 on 31s. The gearing was too tall. Really had to slip the clutch in first gear especially when pulling a trailer. The high overdrive was nice on a flat spot of road though. They grenaded their countershaft bearings eventually and I switched to a C series about 17 years ago and it is still going strong.

[A guy named Rick]

I doubt i will be towing anything at all with it, especially not in the near future. I also have plans to swap to a KA eventually. Also, it is a 2wd, regular cab, running 215/55r16's

I'll crawl under the truck and measure tonight.

[A guy named Rick]

So i measured, it looks like i do have the shorty. weird, i didn't think it was that small. i measured from the front of the bellhousing to the back and it was about 26. from the joint between the front and back half, it's about 14 inches or so to the end of the tail shaft?

[Charlie69]

The long transmissions are in the king cabs as far as I know.