DrFeelGood

Since I have been going through this period of "discovery" and trying to figure out why I cannot operate the clutch with new slave (11/16") and master (5/8") cylinders, I will post the information I have compiled from the factory service manuals. EDIT: mine was fixed by changing my pedal height to 223mm Item 1970 1971 1972 1973 1980-1983 1980-1983 (2+2) Release bearing to diaphragm spring clearance (mm) 2.0 2.0 2.0 0.0 non-adj. non-adj. Diaphragm spring to flywheel (mm) 44 ± 1.0 44 ± 1.0 43-45 43-45 33-35 37.5-39.5 Clutch disk dia. X thickness (mm) 225 x 8.6 225 x 8.6 225 x 3.5 225 x 3.5 225 x 3.5 240 x 3.5 Clutch pedal height to floor (mm) 202.0 202.0 223.0 223.0 203.0 203.0 Pedal free travel (mm) 10-15 10-15 10-15 10-15 1-5 1-5 Master Cylinder dia. (in) 5/8 5/8 5/8 5/8 5/8 5/8 Slave cyl. Dia. (on) 5/8 5/8 11/16 3/4 3/4 3/4

Another curiosity is the spacer indicated in the picture below does not seem to appear in any of my service or parts documents. It is way beyond the 0.2 mm we are taking about here however.

@Zed Head All valid points. I cant say anything about the case to adapter plate. It seats flush and I had to clean it well to make sure the sealant (no gasket there) surface was unmarred. The countershaft drive gear is a possibility I suppose. To be honest, I did not do anything with this part as there were no bearing in between. `Some pics of the counter shaft forward and behind the adapter plate.

Thanks for the reply. I suppose there is always a chance you know? I mis-interpreted or made a mistake, etc... I did check closely when I pressed this part on for two reasons. One, was to make sure it was al the way down (because the was the most obvious source of too much bearing projection) and the second was, I was a little worried I may have deformed the snap ring by "over-pressing" it trying to make sure it was seated fully. I did not go back after assembling the rest of the front to see if it moved. As far as I can tell, it is seated. Also, why was the distance even greater (3.92 mm) originally? To me, the most obvious reason is that I am not measuring correctly. I checked against my 1-2-3 blocks and the calipers are good. I am using my square to make sure the caliper is perpendicular to the surface when I drop the caliper depth. Shrug, I don't know. I will have to make a decision and roll the dice though.

I posted this in another forum and did not receive any responses so I thought I would also ask here. (sorry if you read it elsewhere) I am just wrapping up a transmission rebuild (1980ZX - FS5W71B) and I had a question about the counter-shaft front bearing shim. Backstory, the transmission needed to be refreshed because of a failed counter-shaft (center) bearing. Disassembly revealed that the front bearing distance to the case was 3.92mm (Measurement A) and a 0.2mm shim was installed at the factory (assumed). Looking at the diagram below, 3.92 mm is considerably off the chart and would require something like a 0.3mm machining of the front cover. After rebuilding, the transmission case to counter gear front bearing (measurement "A") was 3.65 mm. Logic tells me that the next increment past the 0.1 shim would be in the 3.52-3.61 range and would be a 0.0 shim (or nothing). Now, I have no idea how many miles the transmission had on that previous setup (drove in my Z for almost 2 decades) but I wonder if the shim and measurement put too much axial load on that bearing that contributed to the failure. Should I: Slap it back together like it was using the 0.2mm shim? (Seriously, it lasted this long and you don't drive more than 500 miles a year anyway) Leave all shims out because that is the closest to what the FSM states. (Who cares what the muppet before did, the FSM knows best) Give up and buy an electric car. Cheers EDIT: I did try tapping the bearing back before measuring. The front counter shaft bearing is a slip fit into the case and the depth is set by being pressed back against the counter shaft drive gear snap ring. The shaft depth is set by being pressed into the counter shaft (center) bearing which is soft pressed up against the bearing retainer. The only way (I can see) to get that bearing to sit lower and thus use a thicker shim is to space the center bearing retainer plate away from the adapter plate, remove the counter gear snap ring and seat it against the front bearing or find a thinner bearing. It seemed like it wouldn't hurt too much so I tried it anyhow.

A little side project while waiting for parts from Japan (and finding a transmission window) was to repair the passenger side lock cylinder. It just won't work with the key. I decided to take it apart. First, to get it out. There is a very small pin on the back holding the push rod mechanism on. Release that pin, (hold onto it tight as it will drop into the bowels of the door) and slide off the lever. Once that is off a quick pull on the clip and the lock is out. Some thorough cleaning and a dry lube saw it working right as rain. But, I did notice the lock hinge was quite filthy. well, take it out and clean it as well. A quick removal and cleaning had it working perfectly as well. Getting this far meant I had to take the door card off and that revealed a completely hardened outer rubber belt and an inner felt belt that was non-existent. I ordered a new inner felt from MSA and it will be here in Aug, Sept, Oct? Pending on that. I did get the outer strip and it is produced by Precision. None of the holes lined up with my original but that was not a problem. some new holes and it fits nicely. This all meant I had to remove the glass and regulator. Well, it turns out that the little plastic dust covers on the regulator pulley wheels were done. I wondered what they were when I noticed them sitting in the bottom of the door. Thankfully, user scottan from Thingiverse uploaded a file so I could 3d print some out of TPA. A wee little stretch and perfect. I also noticed that the door skin had come free from the internal "reinforcement" beam. I re-adhered it and that went a long way in reducing the buzzy vibration. The big step to reducing that was some 8mil Killmat panels. Now that did the trick. Still waiting on that felt....... Cheers

Well, the noise from the transmission decided the end of driving season for me. I have viewed plenty of YouTube videos regarding FS5W71B 5-speed transmission rebuilds that all started with significant chunks of metal attached to the drain magnet. I wasn't looking for that in this Zed. The takedown was pretty easy. A transmission jack from a previous Toyota Matrix clutch (owner gave it to me for helping) got to crawl out from under the bench to help. Everything came apart without drama. Looking at the back of the motor there was a small amount of oil at the base of the rear main oil seal. No worries, I already have an OEM replacement. Pluck and place that one in when I rebuild. The flywheel looked a little weathered. In the past I have given it a little swirlyloo with a sanding block but this time I had Bills Datsun Shoppe in Clackamas pull the dowel pins and machine a new face. Given that is ready to go, I suppose it's time to address the gearbox. Apparently I have a 1980 Datsun 280ZX 5-speed installed. After opening it, I can verify that the bearing on the counter-shaft center-plate is damaged. Things were pretty straight forward on disassembly. I did notice some variances with snap-ring thickness so I documented them. output shaft -- snap ring (1.40mm) -- speedometer gear -- snap ring (1.20mm) -- - -- snap ring (1.17mm) -- bearing (NSK 6205) -- snap ring (1.39mm) -- - -- NUT (27mm x 1.0 pitch) Right-Hand Thread. I thought it may be a Left-hand thread but this was a right hand specimen. The LHT replacement nut is available (at this writing) so I ordered one in advance, (32354-E9803). What I need is a a RHT, (32354-E9804) and that is no longer available (NLA). I did find a 27mm I.D. x 38mm O.D. shim on Amazon in 0.1, 0.2, 0.3, & 0.5mm thicknesses. I was happy to slap a 0.5mm sprung steel shim on there, clock it 180 degrees and call it a day but... I found a manufacturer called Kameari Performance and for the extravagant sum of $49.99, I was able to purchase a "71B Transmission Main shaft Rear Nut (Clockwise Rotation type) for Datsun 240Z 260Z 280Z 280ZX Skyline Cars." - 21-KAME-125. I can confirm today that "El supernut" fits. I am not sure where this gearbox fits in the scheme of things, but it is tagged as a 1980 280ZX FS5W71B. The teeth counts are exactly what a user at Ratsun.net posts for the '81-'83 280ZX box's (pictured below) This gives me ratios of the following: 1st 3.062 2nd 1.858 3rd 1.308 4th 1.000 5th 0.745 R 3.026 From what I see in the literature, this is indeed the ratios found in the 1981-1983 transmissions. The 1980 is reported to have a different 5th gear ratio closer to 0.80 (0.773). The part that is different from my understanding is the later FS5W71B's from 1981-1983 all used a left hand thread main shaft nut. Mine is a right hand thread (like the earlier gearboxes.) 🤷‍♂️ Anyhow, new roller bearings, needle bearings, balk rings, check balls, d etent springs, breather, o-rings and oil seals should see it back to useful service. EDIT: A look back at the picture of parts above, reminded me of the front cover shim. When I disassembled the transmission initially I measured the tolerances and made a note of something that seemed off. According to the service manual for 1980, my counter gear front bearing was sitting 3.92mm proud of the transmission case (Measurement"A"). This would mean that I am just 4-steps away from the the smallest shim of 0.1mm. The case had a 0.2mm shim in place. Not sure what to make of that BUT, it was the the counter shaft (center) bearing that failed. Trans_Rebuild_FEB2012 Marked with orders.pdf

Love the "Do Not Strike" sticker. That was the only way I was able to get the old Ford starters to engage back in high school. We called it a technical tap.

I would use red "permanent" for this. In my head an insert is precisely the thing I want to become permanent. Heat and vibration considered. Unless the insert manufacturer specifies something else. I recall ProjectFarm having an episode about this. I believe Time-Sert with Loctite 271 is the preferred combination. Cheers

I was going to comment this as well. Aside from leakage out the rear ( 🫤 ), the level/angle of the unit may result in over/under fill. My 2-cents.

I love it when people return and close up a thread.

Last weekend I found a jack hold-down at Powerland swap and meet in Oregon. Great chap gave it to me gratis. I still have my antenna up for @Patcon . In preparing to redo my carburetors I discovered a few things. First I have E46 intake manifolds and 3-screw round top SU installed. As I understand it, the Jan 71 car came with 4-screw carburetors (thanks all who educated me here) attached to the E46 manifolds. I do have a pair of those in the parts box (likely the originals). I am pretty sure it does not matter for the rebuild, but in looking at the carbs I notice what seems to be a fair bit of lateral play in the throttle shafts. I think I will try and get on the wait list for one of ZTherapy's rebuilds and have them do a pair of the 4-screws units. There is no real rush with this however as the wait is half a year and the transmission has revealed to be in some degree of escalating protest. When the clutch is released in neutral, the FS5W71B makes a sound that can only be identified as unhappy bearing(s). I have done what I can in ordering parts (before opening and verifying) from anywhere I could find them. I predominantly used the parts list accredited to @EuroDat but also seen widely around the internet. For all parts I ordered everything I could from NissanPartsDeal . com. The rebuild kit with Japanese Nachi bearings, front and rear seals and brass baulk rings from Transmission Parts Distributors. It appears to be the same kit as ones offered by Zstore and the like, but for a significant fraction of the price. I ordered the rear tailshaft bushing from OmegaMachine (#71411) and the selector seal from veryseal . com (TC 14X20X4.5 Metric Nitrile Oil Seal). I ordered some o-rings from Amazon and the rest of the needle bearings and detent/return springs I ordered from Japan through Amayama, (we'll see if they exist and if they arrive). In the meantime I am reading everything I can from this wonderful site, _FS5W71 Rebuild.pdf from Derek Garnier, and a whole host of youtube videos in addition to the factory service manual. I have rebuilt plenty of spinning things with bearings and gears but never a transmission. I do love an adventure but love it even more when a plan comes together. EDIT (07/18): The transmission kit arrived and full of Nachi bearings, but not one from Japan (sigh). They will likely work better than the ones installed now however.

@jfa.series1 That makes sense. It does have a FS5W71B close ratio from a 1980 280ZX (according to records.) The previous owner (brother) swapped it from the FS5W71B wide-ratio that the previous-previous owner (father) had installed. In one of the pics you can see the 280ZX shift boot and plate that I replaced with a 240Z unit. i was not aware that the 1971 and 1972 had any real significant change in center console shifter positioning. I do recall the boots are different size so that must account for it. Thanks for that tidbit. I will do some research on choke cables as the ones currently installed are rubbing some of the paint off the inside of the hood.

I stopped by the car today and confirmed it does have E46 intake manifolds. That would mean the 4-screw units that are bagged were probably original. Another question would there be any reason to change the choke cables with a carb change of this sort? The car has a 1972 dash and center console installed. Would one need to change the choke cables for that console? Thanks again and much appreciation for all the help as I navigate a steep learning curve of nuance.

Thank you Cap'n and jfa, that is useful information. I will look and see what is on the car. There was a 72 in the mix that became a parts donor after a fit of adolescent driving. That date tracks.