Dave WM

Yes that is the one, I tried to order when I got the other parts, but was told it was NLA.

If anyone has one handy, could you pls measure the length of the shifter return spring (just the spring). The reason I ask is I noticed before taking it apart that the shifter felt a little soft on the return (from say the 5/rev neutral point), at least compared to the 4sp. This is the spring has a plunger and is mounted on the side of the rear extension up near the shifter.

I will get a pic of my "clip buster" tool saved (well lets say clip convincer, since it certainly was not going to bust) me from certain madness.

I can tell you there were a few choice words not captured on the video when that snap ring tool broke leaving a chunk of the jaw stuck in the hole. I was about ready to get medieval on it (well not really but I thought about it )

Got tired of waiting for the nut, so went ahead and removed it. Used a punch to flatten out the stake, Nut came off CCW easy. gear puller on the gear worked out easy as well. Now on to the reverse idler, boy oh boy what a pita that was, broke my 1st circlip tool on the snap ring, got out a bigger one this time with fittings that would just barely fit the holes, well then that one broke leaving the tooth in the hole of the circlip. Finally I got some old big long nose pliers, custom ground the tip so I did not have to use the holes, and bingo got it. a little DNA left behind for good measure!! Video soon.

No action yet, waiting on the counter shaft nut to get here (just shipped from MSA today). EuroDat any thing special about how to remove that nut? I presume a punch to lift up the pinned part of the nut? I am not going to attempt to remove until I have the replacement in my hands.

about 1.3 mm I measured by applying pressure on the shift forks to push the brass "baulk ring" up firmly against the steel gear, measured the gap between the brass and steel.

Took it to a local transmission shop "DrZ auto" in winter garden, Spoke to a guy there that has work on these before, he looked over the gears and the synchos, did not think anything looked abused (other than the reverse idler, he echoed the same thing about non synch rear and could be clutch dragging.

I did check the end gaps, they look ok, any pointers are welcome. the shift forks I don't recall a spec on the play but I can certainly get a reading and get back.

EuroDat, how are you able to tell the balk ring tolerance? Or is it that obvious in the photos I attached. I thought I had to pull the gears out to measure that? My background has been in electronics, specifically vintage electronics, which my typical process would go like this: Base line trial (with closely monitored checks of voltage, current, heat). The base line is used as a point of reference so I know if there are any fatal flaws that would make it not worth fixing (unattainable parts). My initial thoughts were to correct the obvious (missing oil gutter, leaking seals, chipped teeth) install and make a base line run. this keeps me low on the budget (but for the time to pull and reinstall which while difficult I think I can handle, I have good jack stands and I am reasonably strong so no $ outlay). Evaluate the base line (noises/shifting difficulty/overall performance). IF the above checks out then stop (do no harm). IF there are issues, then pull down get a rebuild kit (bearings/synchros) and rebuild. Time consuming but it is a hobby after all. I hear you guys though on the why do the base line, just rebuild. Its just not the way I generally do things but then again I have no exp with cars so this is new territory for me. I don't abuse things, so I hope the car will last a long time.

are the bearings a major pain to get off, I have a bearing puller but some of what they show looks pretty special? I have a local junk yard that sells cores for 150$ but with out inspecting them I could be no better off. Just thinking ahead on that.

so maybe just start out with disassembling the main shaft on the front of the adapter plate. Looking over the FSM with the complete tear down looks daunting. If I can get thru that with some lever of confidence maybe I can continue with the tear down. Will have to mull it over, thanks for the input guys! really appreciate it. Re reading the FSM, looks like the main drive gear and 3rd gear are pretty easy, then gets a lot more complicated to get the 1st and 2nd. I think I have to read this a few more times.

there is a couple shops nearby, that I will try to stop by maybe tomorrow. See if they will give me an opinion. My guess is it will be they cant tell anything with out tear down which is fair enough. I would like to put in the reverse idler just in case its fine, but sounds like that may be a waste of time unless I go with a complete tear down. Not sure my skills are up to that. So maybe the best idea is to bolt it up and just give it a try as is. At least I know the propeller shaft that goes into the rear bushing will be getting its supply of oil from the gutter. I don't plan to drive it hard, just was looking for a high speed gear so I can take it out on the turnpike and keep up without spinning 4k all day long.

ok checked the clearances, all looked good except for the OD gear which was more like .3mm vs the max of .17mm per the FSM. I tried for better pics and better video, but could not get much better than what I shot. From the pic you sent Zed Head, I can't really tell if mine are any worse. they look better in person than the pic shows. (I think the oil and blurriness maybe making mine look worse in the pics). I can't account for the larger clearance on the OD all the rest were well with in spec. The reverse idler had the tightest of all. I was reading it like this, 1st gear was the largest starting from the adapter plate on the main shaft, then going forward 2nd and 3rd. The most forward gear was the gear on the main drive shaft, it had no given clearance. The OD gear was on the other side of the adapter plate, last gear on the main shaft, clearance was checked between the gear and the washer before the nut. This was the gear end play. I am not sure I can check the other items listed in the FSM without dissassy of the gear cluster. Update, I found a different FSM for my trans and it said the OD gear end play should be .31-.35 so looks like I am ok on that!! this second FSM seems like a better match they both have the same transmission number but on has ZX on the manual label is the one I was using and had the tighter clearance on the OD, BUT it does not show the anti baulking device. The other manual has the FS5W71b reference, no mention of ZX but does have the anit baulking device like mine and has the larger OD clearance that matches mine.

No history, got local from a young guy, was already pulled. I don't even know if he had used it. I am not into it very much, I can see about checking closer with FSM for clearances. I would have no prob just doing that and if not too bad putting back together and trying it out to see how it goes before doing any more work.

here are some pic. I agree I am at a point where the reverse gear is the only thing that I can SEE has issues, and not sure how bad they are. I am not too far into it right now. I included some pic of the reverse idler as well showing some of the good and some of the bad teeth.

ordered the counter shaft nut from MSA for an 81 ZX from their website, they will ship in a couple days. I presume the procedure is to engage two gears at the same time to lock up the trans, the use a punch to straighten up the peened in part of the old gear, then remove by turning TBD direction. Use new nut to reinstall, tight to 75-90 ftlbs re peen over gear to lock in. Sounds easy but never having done it I suspect its not.

got the Nissan gasket 32112-08U01. Counter shaft Nut will be on the way soon.

I have been cleaning up the inside and the outside of the tail housing, will be getting a new vent piece since the old one is looking fragile. made a copy of the front cover housing gasket just in case I have to make a new one from scratch some day, Started scraping off the old one (I got a new one, check to make sure it was the same fitment before I started scrapping of the old). Question, is the Nissan OE gasket supposed to go on dry? or do I use a high tack gasket sealant (not the RTV stuff but the kind used to hold gaskets in place while buttoning up parts). the reason I ask is I seem to recall reading about how some gaskets are designed to swell in the presence of oil, and sealants can hinder that. It seemed pretty well stuck to the housing side and not at all to the front cover, leading me to think it was stuck on with something, but not coated on both sides.

I will Capt, thanks for the reminder. I found the counter shaft nut and will get a new front seal as well. could not find a Nissan OE front, so hope the aftermarket will be good.

I have some I bought decades ago, think they were made by KD tools, one ratchets open one ratchets closed. Hard part will be to find the little hardened part that was bolted to the tip of the tool, I am missing one.

No hurry, I can wait now that I know I have a fix coming. Loving my Z. Took my wife out yesterday for a drive (funny back in the day I took her for a drive in a NEW 260z that belonged to mom). Really nice to be back in the saddle again of one of these old cars. Besides mom 260, I had a used 240 around 1980. Only thing wrong with it was a bad diff whine right at 55. I ended up selling it to an inlaw a couple years later, he sold it a couple years later, we both miss it. I am really glad I was able to get one again. Added on more video showing the issue with the gear and which one I think I need to remove to get access to the reverse idler.

Fantastic, PM me and we can work on the details

sorry let me rephrase that it looks like 5th gear on the counter shaft (lower shaft) that has to come off to let the reverse idler slide off. The nut on the counter shaft looks like its staked and would need to come off. I made another video but cant upload right now showing what I am trying to describe. will post later.

is that lower nut with the staked washer hard to get off? I think the one large reverse gear is the only one that has to come off the lower shaft in order to get the reverse idler free from its shaft.