Randalla Posted February 9, 2014 Report Share Posted February 9, 2014 Thanks for the great feedback. Guess I'll keep looking. Fortunately the current trans works fine at 60 mph or below, so I can drive it around town at least. Looks like the better way to go may be swapping a manual in. Guess I'll start collecting parts. 1 Quote Link to comment
ggzilla Posted February 9, 2014 Report Share Posted February 9, 2014 What is the problem going over 60 MPH? 1 Quote Link to comment
Randalla Posted February 9, 2014 Report Share Posted February 9, 2014 Engine is reving too high. 1 Quote Link to comment
datzenmike Posted February 9, 2014 Author Report Share Posted February 9, 2014 Have read this thread from the beginning and still have a few questions. My 510 has the stock 3N71B transmission in it currently. Discovered today that I have no third gear so I need to swap out the trans. I have located two transmissions, reportedly in very good shape, a 3N71B out of a 280ZX Turbo and a L4N71B out of a Maxima. My preference is to modify as little as possible (mounts, drive-shaft, drive-shaft tunnel trimming, etc). Is there anybody out there that has successfully mated either of these two transmissions to an L16? If so what modifications did you need to make? . I will say here that I have a '74 L18 automatic 710 and I thought I also had no third gear. If up-shifts to second in about one car length and is very easy to miss. Second to third is mistaken for the shift into second and the motor revs and revs, up and up and up and ????? wtf where's third??? The only way to feel it is to quickly floor it from a start and the auto senses the load and delays the shift point. Under stiff throttle the shift to second is much more noticeable, and then third. Everything was fine. 1 Quote Link to comment
ggzilla Posted February 10, 2014 Report Share Posted February 10, 2014 Engine is reving too high. Is revving over 5000 rpm? Remember the L16 redline is 7000 rpm, yellow line (safe cruising) is 6500 rpm. And the L16 was designed back when speed limit was 75 MPH. It is so good running at high rpm they put in theDatsun pickups (only country that got L16 pickups). 1 Quote Link to comment
kevins750 Posted February 10, 2014 Report Share Posted February 10, 2014 Mine shifts into 2nd before I finish a right hand turn from a stop 1 Quote Link to comment
ggzilla Posted February 10, 2014 Report Share Posted February 10, 2014 I drove a 510 everyday for two years and always thought it was a 2-speed auto. Cruised at 65 mph no problems though. 1 Quote Link to comment
danfiveten Posted February 10, 2014 Report Share Posted February 10, 2014 Mine cruises at 80-85 no issues 1 Quote Link to comment
datzenmike Posted February 10, 2014 Author Report Share Posted February 10, 2014 My auto did 90MPH once. I worked out the RPMs to 5,500 or so. That's nothing for an L18. 1 Quote Link to comment
mo.woodie Posted February 19, 2014 Report Share Posted February 19, 2014 Hi i was wondering which year and car the l4n71b came to australia and would it fit the l20b. Cheers 1 Quote Link to comment
ggzilla Posted February 19, 2014 Report Share Posted February 19, 2014 I would ask on Ozdat forums. 1 Quote Link to comment
datzenmike Posted February 19, 2014 Author Report Share Posted February 19, 2014 We got it on the '84 Maxima RWD (maybe the '83 as well) but that's all. Our Maxima used the L24 so yes our L4N71B would fit any other L series motor with 6 bolt crank. It is about 1 inch longer than the 3 speed 3N71B auto. We did also get it on the '87-'89 D-21 Hardbody with the Z24i and VG30 but the removable bell housing bolt pattern is wrong for an L series. The 300zx VG30 also had the L4N71B but was a heavy duty variant with larger output spline. 1 Quote Link to comment
mo.woodie Posted February 19, 2014 Report Share Posted February 19, 2014 Thanks i'll try Ozdat but this thread was a great read and very informative the 4 speed is the way to go for me . Cheers Quote Link to comment
revhead Posted December 9, 2014 Report Share Posted December 9, 2014 (edited) Hi all, Just joined, but have been reading Ratsun for a long time. I have come across an auto trans for a customer and I am stumped. I usually deal with only manual trans, but this guy wanted an O/D Auto, so I started the hunt for an L4N71B. Found a junkyard in texas with an '83 Maxima, had the trans shipped and so on.. It gets here and it is an 3N71B OD. What did I get? Looks very similar to the L4N71B, bellhousing bolts up to an L28 and everything looks ok except I didn't get the flywheel and the stock 280Z auto flywheel doesn't fit. From what I read I thought the dished flywheel was for the lockup converter, but none of the OD trans in the early years ever came with lockup. I am confused. I tried to get the flexplate from the same yard and they claim they don't have it, but I'm going to try again. I know it was on there at one point because i got the bolts with the converter. Edited December 10, 2014 by revhead Quote Link to comment
datzenmike Posted December 9, 2014 Author Report Share Posted December 9, 2014 Top L4N71B. This one is an L series bolt up although there were Z series ones in the early D-21 Hardbody and the W- 21 Pathfinders Bottom is a 3N71B 3 speed. The L3N71B is similar in looks on the outside but has internally a larger locking torque converter. The L3N71B does not have a 4th gear nor is it overdrive. From what I have observed the L3N71B locking torque converter flex plate (automatic flywheel) is the same as the L4N71B and deeply dished. Locking torque converter from L4N71B (LEFT) and ordinary 3N71B (RIGHT) Flex plate...3N71B (LEFT and L4N71B (RIGHT) Probably already mentioned but the first locking torque converters were installed in mid year '82 vehicles. It was not used on the 280zx turbo but was on the '82 -'83. Maxima '82 only. '83 and '84 was the L4N71B 720 truck 11 '82 and up. No L4N71Bs at all. S110 200sx 12 '82 through '83 1 Quote Link to comment
revhead Posted December 10, 2014 Report Share Posted December 10, 2014 Thanks for the info. I see Pioneer still sells a flexplate for the 720, so hopefully that will solve my problem. I edited my above post because The trans i have is a 3n71b OD, not an "L" version, but yet it still looks like i need the dished flywheel. I can barely find any info on this trans. I assume it is rare, but is it any different from a 4n71b? I'll post pictures tomorrow, maybe someone put the wrong converter in this trans. 1 Quote Link to comment
datzenmike Posted December 10, 2014 Author Report Share Posted December 10, 2014 There were 3N71B and L3N71B but no OD (which I assume is Over Drive?) There were locking torque converters but this is not an over drive. It locks the engine to the transmission input shaft and removes any converter slip. It's 'automatic' in 3rd gear around 45 MPH at light throttle and reduces the RPM 200-400. Slight increase in mileage and transmission runs cooler. 2 Quote Link to comment
OK12V Posted January 12, 2015 Report Share Posted January 12, 2015 I just read through this thread and still need some assistance if you don't mind. My plan is to swap L20B with 3N71B shorty (26" ) in to my Suzuki Samurai. It will be attached to samurai divorced tcase. That's why I can only fit 26 incher in. If I understood correctly from this thread, short tranny came with 510s and 620s, but attached to L16 engine. Is there a vehicle that has L20B and short 3N71B ? I rather look for complete vehicle, so I could make sure it runs and drives before the swap. If there is no such thing, Is there other makes/models years shorty came with? 1 Quote Link to comment
revhead Posted February 9, 2015 Report Share Posted February 9, 2015 Here is what I have.. a 3N71B OD. might possibly be the rarest 80s nissan transmission ever according to the lack of info on the internet haha. It is at the trans shop right now. He is trying to figure out a way to make it a little tougher by adding another clutch plate. He said direct only has 3, OD has 2. It does have lock-up. 1 Quote Link to comment
datzenmike Posted February 9, 2015 Author Report Share Posted February 9, 2015 Got any more all encompassing shots of this trans? The 3N71B from the 280zx turbo is probably the heaviest duty auto made. Has several extra clutches and plates in it and a special shift modulator valve. It also has a special higher stall speed converter. If you want a heavy duty 3 speed this is the one to look for. The later L4N71B is likely as tough but is a true 4 speed. 1 Quote Link to comment
revhead Posted February 10, 2015 Report Share Posted February 10, 2015 This is the only other one I have right now. Leave it to me to find some oddball crap. I requested an 82-83 maxima OD trans and the original one I bought somehow wasn't in inventory, so the guy says they had to go pull this one and this is what was shipped to me. At first glance I thought, great!, looks like the right thing. Now after lots of looking around, I have no idea what application this trans originally was for. It does have the L24/26/28 bellhousing pattern and bolts right up. 1 Quote Link to comment
datzenmike Posted February 10, 2015 Author Report Share Posted February 10, 2015 Yeah that's an L4N71B. They were basically a 3N71B with a fourth gear added on the front. They came out in '83 ish so maybe they were still cast with 3N71B on them. Well the OD really does mean Over Drive. I had an '84 Maxima L4N71B. They were used in the S12 with CA and VG30 engines and the early 2wd D21 Hardbody/WD21 Pathfinder with Z24i and VG30 engines. Only the Maxima had the L series bell housing.... I saved mine. 1 Quote Link to comment
Charlie69 Posted September 29, 2016 Report Share Posted September 29, 2016 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} 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? Mike I forgot to add the 1980 kingcab that the steel pinion and the large gear had a L20B, a L3N71B automatic, and a 4.11 rear end ratio. I have never seen another with this combination. Just curious can I swap the bells housings from a L4N71B 83 Maxima trans with a bell housing from a 1989 Hardbody E4N71B trans. The reason being I would like to install the Maxima trans in my 86 720 z24 king cab, This bell swap if possible would keep me from having to wire in the the E4N71B trans control box. 1 Quote Link to comment
datzenmike Posted September 29, 2016 Author Report Share Posted September 29, 2016 21 tooth is considered purple. I see the color and the ratio differential listed in books and on line. However it only applies and is relative to the vehicle listed. Here's why... A car with a 25.6" tall tire and a 3.90 ratio might use the same gear as a truck with a 28" tire and a 4.11 ratio. You can't just say that an X gear is for a Y differential. Besides different ratios there are optional tires and rims sizes offere on some vehicles. Mike I forgot to add the 1980 kingcab that the steel pinion and the large gear had a L20B, a L3N71B automatic, and a 4.11 rear end ratio. I have never seen another with this combination. Just curious can I swap the bells housings from a L4N71B 83 Maxima trans with a bell housing from a 1989 Hardbody E4N71B trans. The reason being I would like to install the Maxima trans in my 86 720 z24 king cab, This bell swap if possible would keep me from having to wire in the the E4N71B trans control box. I think the bells are the same other than the L/KA bolt pattern. This a 4 cylinder auto? I'm leery of the VG30 auto in fact leery of the E vs. the L designator. The L was a 'lite' heavy duty while the E was more heavy duty. Check that the output spline on the mainshaft is the same diameter and number of splines. This is (I believe) the difference between a non turbo 3N71B auto and a turbo L3N71B in the turbo 280zx. Pretty sure the drive shaft splines count or diameters are different. 1 Quote Link to comment
Edz280zx Posted March 30, 2018 Report Share Posted March 30, 2018 As 83-84 Maxima transmissions are becoming more scarce, I'm wondering if the bellhousing off of the L-series 3N71B would fit on the L4N71B out of the 300zx (or any other vehicle for that matter). I understand that it would involve a different flexplate and torque converter, I was just wondering if they could physically be bolted together? I've been looking for an answer and haven't found a clear one. Anyone? 1 Quote Link to comment
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