I remember the first time that I got behind the wheel of my 240Z! I felt a rush of excitement, and my transmission swap made a world of difference.
If you want to have a driving experience that feels just right for you, you need to balance authenticity and performance. When you're picking between a 5-speed and a 6-speed gearbox, you have the power to completely change the way your S30 behaves. I've talked about the options for each choice based on how the car drives, your restoration plans, and even how easy it is to find the right parts. You want to choose the best setup for yourself, and doing that will turn your ride into something completely yours.
Now is the time for you to make that choice. Let's learn about both options!
Table of Contents
Factory Transmission Options
The Datsun S30 can give you some different transmission options during its long run. Learning about them helps you to be more aware of the driving experience. You have the four-speed manual in the early S30 models, and it can give you a mechanical feel that car enthusiasts still like! You feel the connection with the car when you use it, and it has enough power for those fun backroad adventures. In 1977, Datsun brought in a five-speed manual for US-market cars, and you soon had two options to remember.
The wide-ratio version came first, and it made highway cruising feel much smoother. Later on, you could use the close-ratio version, which racing fans find fun to drive.
I chatted with Mike, who owns an S30 in California. He explained that he enjoys the four-speed and he feels that it seems more in tune with the car's original soul. It makes driving feel a bit more authentic. At the same time, some drivers, like Janet from Texas, have found that upgrading to a five-speed can be a good move. She saw her fuel economy get better on long trips with the extra gear that lets her ride more comfortably on the highway.
Remember that swapping transmissions can become hard pretty fast. You can run into problems - especially because the bellhousing can change from year to year.
What might feel like an easy upgrade can turn into an expensive headache if you don't do your homework. Collectors care about keeping these cars as they were built. They believe that staying true to the original factory setup preserves the history and general worth. That's why you might pause to swap out the transmissions, even when newer options might improve performance.
You should also know about the automatic transmission. In 1971, Datsun started with a three-speed automatic with a hydraulic torque converter and planetary gear sets. It was a setup that created smooth driving. But it might not give you the responsive feel that some drivers want.
The Traits Of The 5-Speed
Your early experience with the Datsun S30 may have introduced you to the classic FS5C71A transmission. This particular setup works because it comes with a two-piece bellhousing design. The fun Monkey Motion shifter mechanism helps to make driving feel playful and fun, too!
By 1972, Datsun decided to take a few items up a notch with their FS5C71B transmission. They made it a bit tougher by moving to a single-piece bellhousing and packing in some stronger internal parts. You can also get a shorter rear extension, trimmed by about half an inch. The transmission is built to manage some spirited driving as well.
You'll see that the FS5C71B is available in two varieties, and they can change your driving feel. The wide-ratio version spreads out the gears so you can enjoy more relaxed and comfortable cruising out on the highway. The close-ratio version gets your engine revving high between changes. It's perfect for when you choose to take your car to the track.
I remember putting these versions to the test during my time back at Willow Springs. The wide ratio felt a little more laid-back in the corners. But it kept you comfortable on the straights. The close-ratio version kept the engine singing right there in its power band through each and every twist and turn.
You might find that the way you can get replacement parts plays a big part in how you end up picking the right transmission. It's harder to track down parts for the earlier FS5C71A (especially since that two-piece bellhousing has become rare now). The later FS5C71B still has parts that are readily available to you, which might help make your life a little easier.
When you choose to swap between these transmissions, then you'll need to plan things out ahead. The different bellhousing designs mean that you can't just bolt one into place instead of the other. You'll need to spend some time thinking about it.
The change mechanisms need a few modifications to get everything working. You might see that each version fits different driving styles and goals. If you like cruising comfortably on the highway, you might lean toward the wide-ratio's relaxed top end. But if you care about track performance, the close ratio's tighter gear spacing could give you that extra edge. And if you're a weekend warrior, you might end up finding something in between to fit your preferences.
When you look at the mounting systems, they can tell an interesting story of development. Early cars used softer, rubber-mounted shifters that helped to cut down on vibration while giving you a gentler feel. Later designs swapped these out for more rigid mounts, which give you better and sharper feedback, though you might see more drivetrain noise.
Possible For A 6-Speed
You can get your Datsun S30 with a few transmission options. The factory offered a 4-speed manual, a 5-speed manual, or a 3-speed automatic, and these were built to work reliably for years.
Enthusiasts have shown that you can also upgrade your S30 with a 6-speed transmission from newer vehicles. Dedicated 240Z and 280Z builders like to use the Nissan 350Z's CD009a transmission, which has tighter ratios and added durability. You can use this modern gearbox. It can give you the chance to experience a refreshed driving process.
When you choose to install a 6-speed transmission, you need to make some alterations to your car. You'll need to modify the transmission tunnel to fit the bigger gearbox. You also need to swap your driveshaft for a custom aluminum unit. Then, you'll need to recalibrate your original speedometer to match the new gear ratios. These adjustments make sure that you get the most out of your upgrade.
The benefits outweigh these challenges if you're serious about performance. A 6-speed transmission lets you achieve better acceleration and precise control on track days. Builders remember that power delivery can become smoother, and general drivability improves after the swap.
You need to plan when converting your transmission. You have to align the L-Series clutch with the new transmission input shaft because this component guarantees that everything operates in harmony. You might see fitment problems with the dual-mass flywheel and clutch assembly heights. That means you'll need custom parts and precise measurements.
You should also think about the cost of a 6-speed conversion. The parts alone need some investment, and if you can't do the work yourself, labor costs add up fast. Builders often spend weeks or even months perfecting their transmission swaps to achieve optimal results.
Recent examples show these upgrades in action. One documented 240Z build showed 231 horsepower and 210 pound-feet of torque at the wheels after installing a 6-speed transmission. The builder credited the modern transmission for unlocking what the engine is capable of. It could give you an engaging and fun driving experience.
Tips For Swap Compatibility
You have been checking your bellhousing alignment - that's something you really want to get right! If your bellhousing lines up well, you can set yourself up for a smooth and successful swap. A small misalignment of just a few thousandths of an inch can cause problems, so you need to use a dial indicator to measure it accurately.
You also need to make sure that the transmission you chose will physically fit inside your car. S30 owners often pick the 240SX 5-speed transmission because it matches the bellhousing pattern, which means fewer problems for you to manage later. Just know that your driveshaft length might need some adjustments.
You should have the clutch setup during the swap process because the parts need to work together well. Check to make sure that your clutch disc, the pressure plate, and the throwout bearing are all compatible - remember that the L-series parts do like to work nicely together.
Some modifications to your crossmember could become necessary to support the new transmission - issues can come up if you upgrade to a more modern 6-speed transmission from a car like the 350Z. It might need some custom mounts to get a fit.
You might have heard some stories on different forums about someone spending a few days trying to find out why their new transmission just won't turn. One owner even found that a machining job on the bellhousing face fixed the binding problems, so you should keep an eye on that area as well.
Also, be sure to look at the shift rod openings. Builders sometimes end up boring out the first and second-gear change rod holes when they upgrade their cars to newer transmissions. This extra step can save you lots of time and frustration later on.
The choice of transmission can change the differential gearing setup because different gear sets can change the final drive ratio. This adjustment can also change how your car performs and how manageable it is to drive. You'll need to remember that when making your choice.
You might find that swapping between transmissions from the 240Z, the 260Z, or even the 280Z is pretty easy. These models share a bit of common parts together. In some cases, later-model transmissions might bolt right in with only minimal work. Enthusiasts like you have said that custom adapter kits can make modern 6-speed swaps way easier, too.
Maintenance And Community Support
The Datsun community is always there to back you up whenever you're working on your transmission. You can join some local clubs or hop onto online forums where experienced owners happily share tips and tricks. They provide input on everything from basic maintenance to rebuilds! You'll soon see that these friendly exchanges can give you lots of advice to make your project a little less scary.
When you need them, you'll find that parts for the stock 5-speed transmission have become much easier to get recently. A handful of suppliers sell Datsun Z transmission rebuild kits that come with everything you might need. You get fresh bearings, seals, and synchro rings that all work well with transmissions from 1972 through 1983. This support helps you handle repairs with a clearer idea of the job.
You'll also like how accessible the documentation for the 5-speed transmission is. The factory service manuals list every single component along with diagrams and specifications. That makes sure you're aware of what you're working with. The community builds on this by giving even more resources that make the process just a bit easier. You can manage repairs with more confidence.
Longtime S30 owners frequently share stories about how the community's support helped them save their transmissions. You could be inspired when you learn about a friend who recently rebuilt his worn-out 1974 240Z gearbox using tips and advice from a forum! He used easy tools he already had, and he spent less than $500 on parts. His car is now running well, even better than before.
Local specialists actively participate in Datsun forums to give expert advice to owners. They frequently share tips about common problems and repair methods that help you stay away from big, expensive mistakes. They also have records of which parts work best and can give you input from people who have done the work themselves.
You might also find that used transmissions from later model S30s can be direct replacements if you need them. A 280ZX transmission bolts right into an early 240Z with only a few easy modifications. This kind of compatibility can give you more options, and the community also shares guides that detail transmission interchangeability.
Finally, forums and social media groups now play a big part in helping you find rebuilt assemblies. You can read firsthand accounts about different suppliers and rebuilders, so you get a clearer sense of what to expect. These real reviews help you feel confident to make well-educated decisions about parts and services so your car receives the care it deserves.
Build Your Dream Car
When you look back at the transmission options that you have looked into, you can see that there isn't one perfect answer for every single build! I've learned over time that chasing the toughest option doesn't always pay off. A well-planned 5-speed swap can give you everything that you need. This helps save you the issue and the extra cost of tracking down rare parts or dealing with hard modifications.
The main factor that matters the most to you is matching the transmission to your goals and your driving style (like how you want to use the car). Whether it's for weekend cruising, track days, or driving, in most situations, you might feel tempted by the desirability of having maximum gear counts. But you might later see that an easier option works for you just as well.
When you start making decisions for your build, you should think about giving your S30 the care that it deserves. At Skillard, we understand that performance and style matter when creating your Datsun. Our catalog is complete with bumpers, aluminum door cards, custom center consoles, and spoilers - all designed specifically for the Z car!
Check out our website to see how we can help to turn your vision into a finished reality. Whether you're just beginning your restoration process or putting the finishing touches on your dream build, we're here to help make it happen.
