Datsun Manual Transmission F4W71B and FS5W71B
The “B” transmissions came in the 1972 240z, 260z, 280z and 280ZX. The 4 speed MT is designated as F4W71B and the 5 speed version is FS5W71B. There is some mixed info on when the 4 speed was available, Z friends say 1972 to 1976, but Chilton Manual # 2800 says 1972 to 1979.
It is easy to identify the 4 speed MT is designated as F4W71B, the rear extension housing has a removable cover to access the striking rod and lever. When you shift gears this rod and lever move to actuate the internal shift forks. The Automatic Transmission designated as 3N71B made by Jetco was Nissan’s only automatic transmission used in Z cars. The gear ratio and housing appear to be the same as the 3N71B.
The Datsun 4 speed manual transmission F4W71B from 1972 Datsun 240z
Datsun 4 speed manual transmission F4W71B Factory Service Manual Data
Year and Model, Gear Ratios, Oil and Capacity and Speedometer Drive Pinion Gear
The Datsun 5 speed manual transmission FS5W71B found in Datsun 280z and 280ZX
The 5 speed Manual Transmission designated as FS5C71B came with different gear ratios and tail housings. There is a “Wide Ratio” that was produced from 1977 – 1980 and “Close Ratio” that was produced from 1981-1983. You can tell the difference between these transmissions by looking at the tail housing.
I took a Transmission and Differential class, so I know a little about them. The gear ratio is determined by the output divided by the input. You actually count the teeth on the gears to do the math. The “Close Ratio” transmission is favored for the close gear ratios. If your racing, the closer the gear ratios are, when you shift your rpm drop is minimal. Looking at both transmissions gear ratios, the Close Ratio gear ratios are literally closer.
Differences between the Wide and Close Ratio FS5W71B 5 speed manual transmissions
There is some great info out there, I got these images from a post POGDEN made on https://www.classiczcars.com. and touched them up. The red, white, and blue (for USA) are the points mentioned in the article. The black text, are my observations from me looking at pics, may not be consistent. Would like feed back on , please.
Datsun 5 speed manual transmission FS5C71B Factory Service Manual Data
Year and Model, Gear Ratios, Oil and Capacity and Speedometer Drive Pinion Gear
Images of FS5C71B for Identification purposes with Service Data and Specification
I created these images also from the Nissan Motor Corp. Factory Service Manuals, they have the gear ratios and teeth count for each gear. OK gear heads, lets see some mathematical calculations. I apologize for the images, some where photo copied. I am a Datsun 240z guy, and have forked out some serious $$$ for hard copies. Feel free to send me your Hard Copy FSM, I will digitize them properly.
I Thank You, for your efforts to keep this knowledge available to the masses for free. FSM manuals came from Xenon### (changed website name to XenonZcar.com) and https://www.classiczcars.com.
Thanks Again!
My Nissan Motor Corp Factory Service Manuals available on https://240z.Life Page
Now here is a problem, possibly a misprint. This is a Wide Ratio Tail Housing, but it has Close Ratio gears. I need some input on this guys. I did notice researching the differentials, that Nissan went back to installing the R180 in the 1979 280ZX, they switched to the R200 in 1975 280z. I believe they were using up the last of the R180s they had. Maybe in this year, they upgraded the gear ratios to the “Close Ratio” but used up the last of the rear tail housings for the “Wide Ratio”. The bolt pattern looks the same, but some bolts are longer because it is a different casting. Not sure.
