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FS5W71B swap into a '73 questions

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I recently acquired a late model FS5W71B 5-speed that supposedly came out of a 280ZX. It definitely has the right bellhousing bolt pattern, the single ear exhaust hanger, the reverse check plate, and the tall ears for the shifter. I've put it in 5th and counted input shaft to output shaft ratios, and confirmed it's the .745:1 5th gear. Based on the research I've done on this site and others it sounds like it should bolt in just fine, but I need to make sure I use the pressure plate and throw-out bearing out of either one or the other and not "mix and match". I have a completely new clutch/PP/TOB (Exedy) that I had bought for my 4 speed, and am guessing that it should be OK in the 5 speed? Can anyone confirm this? Also, the breather has broken off flush with the case. Any advice on removing the stub? The 5-speed came with a slave cylinder, should I use that one or my 4-speed's, or is there no difference? Looking at this web link http://www.atlanticz.ca/zclub/techtips/shifterbushing/index.html I do have the weird oblong shifter (bottom picture, right side) from the 5 speed. Does anyone have any idea what that internal spring is supposed to do in relation to the bushings? Is it one of those push-down to engage reverse features? Finally, this transmission only has one electronic sensor installed, up near the front (Reverse switch I believe), and nothing else. There looks like maybe something should be in the rear, and possibly got broken off. I need to do more cleanup in that area to be sure. I downloaded a copy of the '83 FSM from Xenon and the MT chapter shows 4 sensors! (Reverse switch, Top Gear Switch, O.D. Gear Switch, and Neutral switch.) In all the pictures of these transmissions I have found on line I have never seen 4 switches installed on the side of these transmissions. Does anyone know what the deal is on what reality appears to be VS what the FSM is calling out? In my picture the 5-speed is on the left, the 4-speed is on the right, The shifter with all the tape around it is the oblong one out of the 5-speed. The boss that is up from the tailshaft on the right of the center casting part line (red arrow pointing to it) is full of crud and I suspect where the neutral switch should be installed. Is there ANYTHING that anyone can advise me on in regards to making this swap successful? Pitfalls? "Gotchyas"? "As long as you are doing this you may want to..."? Thanks!


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The throwout bearing collar, or sleeve as Nissan calls it, has nothing at all to do with the type of transmission.  They, the transmissions, are all the same, as far as the position of the clutch fork pivot ball.  The sleeve must match the pressure plate and flywheel.  Don't pay any attention to all of those lists and charts showing 4 speeds and 5 speeds and the various sleeves.  They will send you the wrong way.  Take the measurement from the flywheel surface to the ears of the collar.  It's documented in several threads on this site and others.  92 mm.


Put the transmission in to the gear for the switch you are worried about and measure resistance at the switch.  Then put it in neutral and measure again.  That will tell you if the switch is actuated by the gear that you've chosen.


If you use a Z shifter to replace the ZX shifter, check that the base of the shifter doesn't interfere with the area that it inserts in to the control mechanism.  This can cause it to not fully engage in 5th gear.  A fairly common problem.

Edited by NewZed
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Thanks for the quick reply NewZed. So it looks like my original flywheel, plus the new '73 clutch, Pressure Plate, Throwout Bearing AND '73 sleeve/collar mated to the 5-speed should work fine. Motorsport Auto only has 1 slave cylinder for '73-'83 Z & ZX (non turbo) cars, so that answers that question (which is great since I replaced both the master and slave cylinders not too long ago). Thanks for the heads up regarding the use of the original 4 speed shifter in the 5 speed, that tidbit wasn't mentioned in any of the discussions I have (so far) come across.  Now, I "just" have to finish putting my engine back together in order to find out just how well the 5-speed works out for me. 

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  • 2 years later...

Mr. Bob... was your issue with the neutral switch resolved??

I have that same tranny, but do not have a tapped hole where the red arrow is pointing to.... has me a little confused.  It's just a blind hole, no threads.

Maybe the engineers used a different trigger for the neutral position.

thanks, joe

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Hi Joe, so after I cleaned out the crud in that hole I did indeed discover it to be a blank. No threads at all, but it has the appearance that it might be able to be drilled out and threaded, which perhaps they did for a different market or application, since that tail casting could have ended up in a different car or truck when mated to a different bellhousing. So yeah, kind of weird that the 5 speed ONLY has a reverse sensor, where as my old 4-speed had both the reverse and neutral sensors. In the end I think I just left the neutral wires in the chassis harness unconnected, but the car will still start in neutral. I'd have to crawl under there to be sure... maybe I connected those neutral wires together? The memory is fuzzy now. FWIW having the 5 speed is GREAT, especially when everyone around you on the freeway wants to be doing 80MPH. I can keep up with traffic and stay below 3000 RPM (stock rear gears). 

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