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datzenmike

Datsun L series auto trans pix

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Automatic..1st....2nd...3rd.. 4th....rev

L4N71B ... 2.458 1.458 1.00 0.686 2.182

 

Hey Datzenmike, doesn't that mean that 4th is technically a better gearing than even the 5th speed on a FS5 series transmission?? BTW: Excellent write up about this obscure transmission, it helped me find the S.O.B. at my local Pick-N-Pull.

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Better? depends what you want. The '80-'83zx has an o/d of 0.745 in 5th, so yes, it (L4N71B) would be a larger over drive than that. It wouldn't be better for a heavier truck with small 4 cylinder as is might lower the RPM too much for cruise speed specially against wind or hills. For a much lighter car, a car with gears or a truck with low gears this trans has merit.

 

The L series L4N71B was used only with L24 six cylinder engines with more torque. In fact 4 cylinder L series engines weren't even made any more when this transmission was built

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Better? depends what you want. The '80-'83zx has an o/d of 0.745 in 5th, so yes, it (L4N71B) would be a larger over drive than that. It wouldn't be better for a heavier truck with small 4 cylinder as is might lower the RPM too much for cruise speed specially against wind or hills. For a much lighter car, a car with gears or a truck with low gears this trans has merit.

 

The L series L4N71B was used only with L24 six cylinder engines with more torque. In fact 4 cylinder L series engines weren't even made any more when this transmission was built

 

Agreed on both counts. I have an Army injury that pevents me from being able to drive stick shift, and for nostalgia sake, my 610 4 door came with automatic anyway, so no hard feelings about the loss there. I would LOVE to have 5 speed, but why have a car you couldn't drive? I lucked out with my find: The L4N71B trans was behind an L20A, extremely rare here stateside, but someone down at the used Japanese engine shop must have seen this L series 6 cylinder and thought it was an L24, and stuck it in the '84 Maxima I found it in. As for my luck, it gave me a 6 bolt flex plate, instead of the 5 bolt which would have been worthless on a L20B. :D

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Better? depends what you want. The '80-'83zx has an o/d of 0.745 in 5th, so yes, it (L4N71B) would be a larger over drive than that. It wouldn't be better for a heavier truck with small 4 cylinder as is might lower the RPM too much for cruise speed specially against wind or hills. For a much lighter car, a car with gears or a truck with low gears this trans has merit.

 

The L series L4N71B was used only with L24 six cylinder engines with more torque. In fact 4 cylinder L series engines weren't even made any more when this transmission was built

 

Datzenmike, what would you do: I need some advice for my 4 door 610project. I have a parts car 2 door 610 with a set of 3.70:1 gears in the back, but I want some better speed, so I thought getting a set of 3.36:1 gears out of a Turbo Z would be the right thing to do. Now I can't drive stick (nerve damage in legs from Army injury) so I plan to run the 4 speed auto. Which gears would you use? :confused:

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Guest jaimesix

Hey William.

 

I was reading this thread. The transmission you have from my car is the 3N718?? or the F4W63? I do not recall, last time I drove on that gear box was 04. My books do not specify which one was in the car. The books mention both.

 

That gear box is in excellent condition. The ratios as I remember worked very well, no forcing of the engine, no high RPM syndrome. My advise would be to go with that transmission, it is in great shape. If you find you are not satisfied with it later on, you can always look for another one. Good thing is that the one you got is in good shape. Getting a tranny of a junked car is a gamble, and you would be betting your life on any junked trannies.

 

There are other ways to play with the results, by using another differential. Once the car runs, you will be able to test and tune the car to your particular specifications.

 

The L20B is an engine that has great torque, the best of them all ( L series 4 cyl.) I guarantee there will be no problems power related.

 

Like the old cowboys say," No aiming w/o unholstering.":)

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jaimesix - yes to answer your question, the transmission I got from you is the 3N71B, but I was able to score a L4N71B, the 4 speed variant. I want the overdrive, a little less on the RPMs for the freeway driving that I mostly do. Just trying to keep the life in the engine a little longer. I don't doubt the transmission you gave me still has life left in her, just want to have the options available to me. While I have the car in for bodywork, my friend is going to help me fab a mount for the rear of the 4 speed, so I can keep the stock 3 speed available in case I need it. Didn't want you to be disappointed. :mellow:

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Guest jaimesix

Hey William.

 

No worries, not dissappointed at all. The transmission is in great shape, so it will make a great back up unit.

 

I drove to Shasta on that transmission/L20B set up, and it drove great, the RPM was not that high. My 710 with 4 speed manual is a lot worse at full speed on 4th gear.

 

I will be dissappointed if that 4 door never makes it to the roads!

 

Jaime.______________________________________________________

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Hey William.

 

I will be dissappointed if that 4 door never makes it to the roads!

 

Jaime.______________________________________________________

 

Don't say things like that! It scares me:eek:

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So what autotranny was stock in the 79 620? The 3N71? What would be the logical upgrade? (closest to bolt on and easiest to find)

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So what autotranny was stock in the 79 620? The 3N71? What would be the logical upgrade? (closest to bolt on and easiest to find)

 

Likely to be the 3N71B. Straight 3 speed auto. I am having to fab a custom mount for the L4N71B, which is the 3 speed with overdrive (pushbutton off). You cannot use the 3 speed driveshaft, the output splines are different. So, for logical upgrade? I would say the L3N71B with locking torque converter. Models? I am not sure. Datzenmike would probably know.

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Datsun/Nissan Transmissions

Gearing Chart

 

--------------------------------------------------------------------------------

Notes

Gears ratios/% change on upshift

 

Tranny Model # description

Application 1st 2nd/% 3rd/% 4th/% 5th/%

510 R3W56L

3 spd column shift 3.263 1.645 1

 

510 Sedan F4W36L

4 spd "A" type 3.382 2.013/40% 1.312/35% 1/24% w/L14 or L16 motors only

510 Wagon F4W36L

4 spd "A" type 3.657 2.117/42% 1.416/33% 1/30% w/L14 or L16 motors only

Roadster 1500 4 spd 3.515 2.41 1.328 1 Design unique to 1500

Roadster 1600 F4C63L

4 spd "A" type 3.38 2.01 1.31 1 w/Porsche (servo) steel synchros

Roadster 1600 F4W63L

4 spd "A" type 3.38 2.01 1.31 1 w/Warner brass synchros

Roadster 2000 FS5C71A

5 spd "A" type 2.957 1.858/37% 1.311/29% 1/24% 0.852/15% w/Porsche (servo) steel synchros

Roadster 2000 FS5W71A

5 spd "A" type 2.957 1.858/37% 1.311/29% 1/24% 0.852/15% w/Warner brass synchros

240 Z F4W71A

4 spd "A" type 3.549 2.197/39% 1.42/34% 1/30% US spec

240 Z FS5C71A

5 spd "A" type 2.957 1.858/37% 1.311/29% 1/24% 0.864/14% non-US spec

260 Z

(2+2) FS5C71B

5 spd "B" type 2.906 1.902/34% 1.308/31% 1/24% 0.864/14% non-US spec - same as Nismo C/R OD box

240-260 Z F4W71B

4 spd "B" type 3.592 2.246/37% 1.415/35% 1/30%

280 Z F4W71B

4 spd "B" type 3.321 2.077/37% 1.308/37% 1/24%

280 Z FS5W71B

5 spd "B" type 3.321 2.077/37% 1.308/37% 1/24% 0.864/14%

280 ZX (8/78-7/79) FS5W71B

5 spd "B" type 3.321 2.077/37% 1.308/37% 1/24% 0.864/14% also 810 Maxima

280 ZX (8/79-6/80) FS5W71B

5 spd "B" type 3.062 1.858/39% 1.308/30% 1/24% 0.773/23%

280 ZX (7/80-6/83) FS5W71B

5 spd "B" type 3.062 1.858/39% 1.308/30% 1/24% 0.745/26%

280/300 ZXT

(81-84) FS5R90A

5 spd "C" type 3.5 2.144/39% 1.375/36% 1/27% 0.78/22% Borg/Warner made T5

300 ZX F5W71C

5 spd "C" type

300 ZXT (87-89) FS5R30A

5 spd "C" type Nissan made variant of the B/W T5 style tranny

200 SX (70-79) 5 spd 3.382 2.013/40% 1.312/35% 1/24% 0.854/15%

 

200 SX (6/79-6/81) 5 spd 3.321 2.077/37% 1.308/37% 1/24% 0.864/14% w/Z20E motor

200 SX (7/81-9/83) FS5W71B

5 spd "B" type 3.592 2.246/37% 1.415/35% 1/30% 0.813/19% w/Z22E motor

200 SX (10/83-10/84) 5 spd 3.592 2.057/43% 1.361/34% 1/27% 0.813/19% w/CA20 motor

200 SX (11/84-2/86) 5 spd 3.321 1.902/43% 1.308/31% 1/24% 0.833/17% w/CA20 motor

Nismo

Truck C/R OD FS5C71B

5 spd "B" type 2.906 1.902/34% 1.308/31% 1/24% 0.864/14%

Nismo

Truck W/R OD FS5C71B

5 spd "B" type 3.321 2.077/37% 1.308/37% 1/24% 0.864/14%

Nismo

Truck DD F5C71B

5 spd "B" type 3.321 2.27/32% 1.601/29% 1.24/22% 1/19%

521 Truck

(68-73) F4W36L

4 spd "A" type 3.657

3.382 2.117/42%

2.013/40% 1.416/33%

1.312/35% 1/30%

1/24% w/L4 series motors

used both gearset variations

620 Truck

(74-80) FS5W71B

5 spd "B" type 3.592 2.246/37% 1.415/35% 1/30% 0.813/19% w/L16 and L20B motors

720/D20 Truck

(80-86) FS5W71B

5 spd "B" type 3.592 2.057/43% 1.361/34% 1/27% 0.813/19% w/L20B, Z20, Z22, & Z24 motors

D21 Truck

(86 and up) FS5R30A

5 spd "C" type

 

 

 

 

Nissan made variant of the B/W T5 style tranny

Nismo

W/R OD FS5C71B

5 spd "B" type 3.321 2.077/37% 1.308/37% 1/24% 0.864/14%

Nismo

C/R OD FS5C71B

5 spd "B" type 2.906 1.902/34% 1.308/31% 1/24% 0.864/14%

Nismo Opt 1 DD F5C71B

5 spd "B" type 2.818 1.973/30% 1.47/25% 1.192/19% 1/16%

Nismo Opt 2 DD F5C71B

5 spd "B" type 2.348 1.601/32% 1.296/19% 1.138/12% 1/12%

Nismo Opt 3 DD F5C71B

5 spd "B" type 2.192 1.601/27% 1.47/8% 1.138/23% 1/12%

Nismo Rally DD F5C71B

5 spd "B" type 3.321 2.27/32% 1.601/29% 1.24/22% 1/19%

Nismo

Ultra C/R FS5C71A

5 spd "A" type 1.858 1.388/25% 1.217/12% 1/18% 0.852/15%

Nismo

Middle C/R FS5C71A

5 spd "A" type 2.678 1.704/36% 1.262/26% 1/21% 0.852/15%

F - Type of control F=Floor (direct) R= Remote

Abreviations S - Tranny style S=special overdrive top gear (no letter indicates direct drive top gear)

C/R=close ratio 5 - Number of forward gears 3 spd, 4 spd, or 5 spd

W/R=wide ratio C - Drive/Synchro type F=front wheel drive R= rear wheel drive W= Warner synchros C=servo synchros

OD=overdrive 71 - Gear-pair center-to-center spacing in mm (distance between mainshaft and countershaft)

DD=Direct drive A - Sequential model version suffix (alphabetical)

"A" type - shifters are rubber mounted (infamous monkey motion) "B" type - shifters have a solid cross pin

"C" type - shifters are retained in a top cover plate by a circlip (called a "top loader" in American tranny

 

http://www.gracieland.org/cars/techtalk/gearing2.html

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Well my question is super duper simple , what transmission has overdrive that will bolt up to my l18 in my 1074 629 short bed ? without no modification like changing how long my drive shaft is or modding my transmission mounts or anything like that .

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Datzenmike, can the lock up torque converter be used in an older transmission (3N71B or L4N71B) that did not originally have a lockup torque converter?

 

Do you happen to know the part # for the lockup torque converter?

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How does the L4N71B do coupled to a stock L20B?

 

What gearing would you suggest for my 520 with an L20B & 3N71B?

 

What gearing would you suggest for my 520 with an L20B & L4N71B?

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Datzenmike, can the lock up torque converter be used in an older transmission (3N71B or L4N71B) that did not originally have a lockup torque converter?

 

Unfortunately the locking torque converter tranny is also different inside the transmission itself. You can't just swap on the one part. BUT you could get a lock up tranny from a 720 truck and because the front bell is removable, you could swap the L series bell onto it. Voila'. Oh yeah the torque converter is larger and the flex plate is also different shape to fit this. So you would need those parts too. This is a picture of a locking and a regular flex plate from the engine side:

 

autostdflywheel001.jpg

The L4N71B is a 4 speed transmission and was never equipped with a locking converter.

 

 

 

 

How does the L4N71B do coupled to a stock L20B?

 

What gearing would you suggest for my 520 with an L20B & 3N71B?

 

What gearing would you suggest for my 520 with an L20B & L4N71B?

 

 

Well that is a very tall overdrive ratio but at least it is an automatic and a certain amount of slip is built in.

 

For an empty truck I think 4.375 is fine with the 3N71B automatic and even with one converted over to locking converter. The RPM drop is only a couple of hundred at 40-50 MPH I think. Don't forget both trannys have the same first three gear ratios but the L4N71B has about a 30% RPM drop in 4th. This means a 3000 RPM cruise on the highway at 60? in third, would drop down near 2000 RPMs in 4th. Will an L20B have the power at 2,000 RPMs to push the truck through the wind at 60 MPH? Don't know. At least on hills or windy days the 4th gear can be switched off manually.

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Thank you Mike as always you are very helpful with your knowledge and pictures.

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I have a question regarding a few variants of the L3N71B gearboxes..

 

We have a total of five of them, and all have the longer tail sections. My question pertains to the castings on that tail section; on the driver side (same side as the 3N71B/JAPAN casting is) I found four different casting codes: 1A, 3A, 1B, and 2B.

 

The 1A we know for certain came out of a 72 240Z. One with the 1B casting has a tag on it from a previous owner (no knowledge of how accurate the tag info is) that says "'81 200SX." There is a second box with this tailshaft casting on it. The 3A casting has a mark on it (looks like shoe polish almost?) that reads wither 5, 6, or 810. (I was presuming 510 while looking at it but had to admit it could have been any of the three.)

 

Now, we've got a gentleman who is interested in a 260 short block/head/flattop collection of separate parts, as well as the transmission from the Z. Unfortunately, the TC from the Z-car was thrown away, but the 3A gearbox has one in it.

 

Do any of you guys have any information that can help me with these different castings? Are the tail sections essentially the same as long as they are "long?" I would presume this torque converter works for the Z, but I am not certain the guy will need it; he has a running AT right now, this would be a spare (or, possibly, five spares?)

 

 

 

Interestingly enough, this Jatco gearbox is also used broadly in Subarus of the 80s and into the 90s; Subarus 4EAT is a 4N71B with some interesting modification done to fold it in half, and the 3AT was a locking 3N71B as well. This gearbox has been around the block ALOT.

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Post the numbers on the tag on the right (pass) side, I can try to ID the trany from that. The 1A 3A and such are like just casting revisions. Some small change that doesn't affect it's use.

 

The PL 510 auto had a short tail so if it was a 510 it may have been from a later HL510.

 

The '81 200sx would have the Z series bolt pattern and won't bolt properly to the L series.

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That casting was the only one I noticed (although I must confess, after noticing the model number and that stamping i did sort of stop looking.) so is this another cast-in mark I an looking for on the passenger side?

 

I'm going to need to make an L-series and a Z-series bell housing pattern to ID the two anyhow; we've got these four autos plus eight, nine, ten or more unidentified manual gearboxes. (monkey motion and non, some of those roadster) It wouldn't be too hard to find some signboards left behind by a failed primary candidate and make up a couple of round bits with holes in the right spots and an outline, would it?

 

I should have looked harder at the tail housings, but some of these gearboxes were pretty buried and simply getting to this one mark on all of them was something of a feat! I am about 85% certain it was the same length tail on that box; when I first saw the shortened one my mind balked.

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Datzenmike or anyone else that might know the answer to this question please reply.

 

I pulled the speedodrive pinion out of a 1980 720 king cab L20B with what I thought was a 3N71B transmission. The tag on the inside of the passenger inner fender well does not list the rear differential ratio on the 1980 720. The black 1980 Drive pinion is made out of steel, the 1984 drive pinion is aluminum.

 

Violet or white or beige (unsure of color bad eyes) 21 teeth 1980 720 KC L20B L3N71B? HF?? Blue 18 teeth 1984 720 Z24 L3N71B HF38 (3.889}

 

DSC01096.jpg

 

DSC01095.jpg

 

I am wondering what rear differential ratio would be for the violet 21 tooth gear would be?

 

Also would like to know if the 2 drive pinions are interchangeable due to the diameter difference of the gears?

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Charlie, yes the pinions changed to aluminum ( I'm not sure when, around '80 ) but other than steel or aluminum they fit the same. I have asked others about this larger diameter and they assure me it works.

 

Ignore the ratios, probably for a car with smaller tires.

Speedocogs.jpg

 

.

 

All automatic 720s after Nov '82 with Z24 motor used a 3.70 ratio rear end and the blue 18 tooth pinion.

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Hi Mike, I have personally pulled 3 Blue cogs out of 84 85 automatic standard cab 720 trucks with the passenger side plates reading HF38. I thought HF38 translated to H190 3.889:1 Ratio

 

Here is a plate I pulled from the truck I got the blue cog from.

 

DSC01097.jpg

 

Sent you a PM

 

Thank you Mike.

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