After an arduous battle to fit my Datsun truck transmission into the 240z’s tunnel, I finally bolted it up… and was sorely disappointed that I had to remove it once again.
My throwout bearing (pictured) was pressed directly against the clutch, and the clutch fork wouldn’t budge. Since driving a manual car is impossible without a clutch, I had to reinstall the throwout bearing. A phone call later, I had ordered some friends. Another phone call later, I had pizza en route so those friends I had ordered would stick around and work on fitting the transmission back in with me.
Everything went relatively well, and I found out that the 280zx-t (s130) driveshaft fits beautifully in place of the stock 240z driveshaft. That’s a bonus because it’s a lighter and stronger unit, decreasing my rotational mass, which increases drivetrain efficiency (throttle response, overall power, mileage).
If you’re swapping transmissions any time soon, it’s a good idea to install the transmission onto the engine outside of the car, and make sure you attach the driveshaft to the transmission before the transmission is in place. It can be a real pain to detach the transmission from the driveshaft, since there are 4 bolts holding the two together and they can get pretty dirty over time.
Finally, there’s a 5speed transmission that’s correctly installed. Cross one more thing off the to-do list, and tackle the next.
If anyone can help me identify the transmission I finally ended up using, that’s be great. I believe it’s a FS5R30A because it came out of a pickup. If that’s true, I’m a very happy camper because it means I have a 1:0.751 or 1:0.711 ratio 5th gear, meaning 70mph will run at very low rpm). That should put me in the general vicinity of 2500rpm @ 70mph
for reference:
(205*.50*2)+355 = 560mm = ~22 inch overall diameter tires
| Rpm = | mph x gear ratio x 336 |
| Tire diameter (in inches) |
rpm = (70mph * (.751 * 3.3 ) * 336) / 22 = 2 649.5rpm @ 70mph
I still need to calculate exactly when the turbo will begin to spool up and when max boost is reached, but that rev range should be perfect for cruising and daily driving. The lower gears on truck transmissions are generally very close-ratio, which works great with the wide rear differential to keep my revs down for long drives.
