Oceanzide

Thanks Yarb! (in this case I was very lucky.) I know nothing about such a conversion, though someone here can probably help. Luck/Cheers..

Well, the new ones seem to be identical to the old ones. Pic shows new synchros installed. The old ones are below (in pic).

Thanks, that's a great idea! BTW, apparently the nut is no longer available either.

I planned to replace synchros this weekend, but found a mangled locking plate behind nut on "output shaft". I'm guessing this plate used to have a tab - the one I found stuck to the magnet on drain-plug. The locking plate is simply not available. The nut is a bit loose but mangled plate prevents it from turning. I'm thinking of just putting everything back together, as is, but wondered: perhaps I can purchase another nut and lock the two together? I also read that someone FOUND this nut "lock-tight"ed. Any suggestions?

I certainly would not spend time on the transmission if it was shifting well. Years ago, my neighbor gave me a drum of 85W gear oil that he used in his Peterbilt. Thinking all gear oil was the same, (and new was better) I put it in the Z transmission and differential. Now (20+ years later) it's a chore to get the trans into just about any gear but 2nd, and fast shifts are impossible.

Thanks Jim! I see some pictures that show a grey bearing surface (mine don't have); there may be better quality synchros out there. Removed trans this weekend, but won't crack it open until next Sat.

Until last week I'd never heard of these folks, and I was ready to spend $20 EACH plus shipping, for 4 parts. Their website turned-up when I searched the part#. NOTE: It's important to search the part#; using the home page Mfr/Year filter didn't show ANY parts for pre 1980 Zs. Also note, the web price (~$8 at this moment) is slightly higher than at the counter (see counter receipt below).. They said they also sell bearings. I hope to drop F4W71A trans soon and promise to post-back regarding whether these actually work.? https://www.anaheimgear.com/index.php?route=product/search&search=32604-P0100

Yes Zed Head, you're right! PN: 32604-P0100 (AKA: "RING-BAULK) Items 39 and 44 in schematic. (Apparently less than $10 at a "local" place). I only read Jim's reply and started hunting for information. (After a couple of hours searching; also chasing our cat to give him meds) I stumbled across a large pdf with lots of part numbers. Would anyone be interested in the rest? (it's ~40M ). I included section 177 because it shows the Nissan publication number. By the way, how do I delete a duplicate copy/pasted image? Edit, thanks Z.H. BTW, I see the same microfiche publication "C-0010V" is already available under Resources tab.

Hi, I'm looking for brass synchronizers for my early 4spd. I found one that supposedly fits a 240 through 280 (1st though 4th). Are the synchronizers (1st through 4th) for early 4spd (1970 through mid 71) really the same as those in later transmissions? Can anyone recommend a source?. Thanks in advance!

Thank you for that - will certainly check the float setting. I know there's a robust attachment being sold for dynamically monitoring the bowl/fuel level, but I'm thinking about temporarily inserting a "T" or "Y" between bowl and nozzle, using a clear tube on 3rd branch (which will just be suspended above the bowl). It kinda depends on how easy it is to remove the stock tube (which I don't want to cut).

Just wanted to follow-up, as the engine is idling smoothly now. Turns out the front-carb nozzle was quite stuck as well. The main problem with idle was that I'd managed to completely back-off the rear throttle adjusting screw while trying to balance carbs (with both nozzles stuck). By turning rear throttle-adjust clockwise a few turns, the idle smoothed-out considerably. I'll need to go through the carb-balancing again. By the way, the default mixture adjustment of 2.5 turns down seemed OK for the front carb but seemed to be way (2+turns) off for the rear (as indicated by a Colortune). I'm not sure whether to worry about the apparent lack of symmetry.

Thanks guys. Last couple of weekends have been cool and wet here, so I didn't work on it until today. I checked the three (rear) plugs, which looked a little dark brown, but otherwise practically new. Gap was OK on all. The front bowl was clean last time I looked, but there's usually a fine dust at the bottom of the rear bowl. Re: nozzles, Huge THANKS for mentioning it! Rear nozzle was _really_ stuck. Re: valves, I have heard some valve noise (tapping under valve cover), so was considering this too. I balanced the carbs a few weeks ago. I'll focus on mixture-adjustment again, next weekend, weather conducive. Thanks/Cheers.

Thanks for catching that!?

Thanks Mark, Dismantled the brass check-valve including spring-clip which retains a tiny spring and "plunger". Squirted everything with WD40, Swabbed-out brass seat with Q-tip. Bent float-tab slightly to lower float. Assembled. Still hard to start and idles like crap. Re: Adjustments: At this point I've disconnected the rear fast-idle(AKA"choke") which (as far as I could tell) wasn't pushing on anything anyway. I've twisted the mixture adjustment and put them both 3/4 turns clockwise from bottom (near where I found them). I've seen posts that advise a coarse tuning of 2.5 turns clockwise from bottom, but mine only have about 2.5 turns total adjustment!(?) I've now changed the float level in the rear bowl. Now the front carb seems more prone to cough/backfire than it has on the last couple weekends. That is, when trying to start the engine - on front 3 cylinders.

Greetingz! Since starting my Z recently - after 10-15 years of mostly sitting - it hasn't been idling well. At first I tried starting the car on 10-15 year old gas and quickly discovered the fuel line was clogged because the tank was full of rust. The gas tank has been cleaned/treated, and I'm using fresh 91 octane fuel. The first indication it was a rear-carb problem was that starter fluid had almost no effect on the rear carb. Then gas came out of the rear-bowl overflow; I rapped the bowl with a screwdriver handle, that stopped the gas pouring out, but the next time I pulled off the air-cleaner, there was gas pooled at the bottom of the carb's air-inlet. Motor runs great when I accelerate, it's just difficult to start and has rough idle. So, I plan to pull apart the rear float-bowl check-valve (yet again) and, this time, focus on the inlet side aluminum cylinder and seat (part of cover). Does anybody have any tips regarding "refurbishing" these check-valves? I've seen several threads regarding stuck check-valves, but not much on how to refurbish the old parts.

There's a check-valve built into the (front of) rear piston. It's supposed to close when applying brakes. When pedal is released, if there's less pressure in front of piston, fluid can move from slotted part of piston (reservoir) forward, past the front seal (of rear piston). This was stuck open. I tried to dismantle the front&rear orifice, but don't have a bench or vice and was never able to unscrew the large fittings. Thank you for the that link Zed Head - I'll check it out (later, when not constrained to phone GUI).

Thanks for the pic! I have two old Chilton manuals that cover 240 to 260 and 240 to 280, also a Clymer covering 240 to ZX - none of them shows cutaway of early MC (To be fair, Clymer shows the most accurate diagram of early Tokico MC.) Where did you find this pic? Re: "Rear Orifice" (not to be confused with PC virus "Back Orifice") If that's the little plunger under the "dome" on the end of the rear piston, then that was the problem! It wasn't a stray rubber fragment, though... It appears these parts are anodized aluminum, and the anodization was chaffed off the plunger right behind the rubber seal. So that's where some sort of corrosion developed and the plunger was stuck/glued about 2mm away from being closed. Am able to bleed MC now - what a relief! Hopefully the vacuum booster is OK. I stuck my finger inside and felt the rubber which seemed very pliant but not wet. Thanks to all for the help and suggestions.

Thanks Zed Head. My signature has model-year, also (now) VIN#. Checked out those Rock Auto links, I might take the 71 option, but for now I'll just see if new seals will solve the issue (if I can find them). Actually, I'm still trying to figure out what's happening. I'm not seeing fluid inside car, so rear seal must be working. Pressure is being transferred forward to front piston, but not fluid, so floating/middle piston seems to be working. Is there a check valve that could "stick" and cause this?. i'd like to see a cutaway of the old-style MC, but my manuals only show the same cutaway picture as you attached above, which is for later model MC.

Hi Zed Head, I'm not sure if you mean there are remanufactured MCs with the "F" mark in front? (Where?) Hi grannyknot, I don't mind purchasing aftermarket if it looks like OEM. I'm just not finding an aftermarket MC with the "F" marking in front. I'll probably end up getting the newer MC and swapping the lines underneath, but have not yet given up on the possibility to keep the OEM look/equipment. Will probably get a quote to have mine "sleeved" & rebuilt (, though expect that will be prohibitively expensive).

Thanks, all, for the help so far. Today I reinstalled the MC and used Patcon's MC bleed suggestion with clear plastic tubes. I was able to see bubbles in both reservoirs, but only the front one completed the fluid-loop with fluid completely filling the plastic tube. The rear tube never pushed out all the air, and the level in the tube only came as high as the level in the reservoir. Now, no more bubbles come out and as I press the pedal, the level in the rear reservoir goes up (even with plastic tube removed). I think it's time to look for seals. Will a later rebuild kit include the same seals as were used in the early MC?

Thanks Jeff. i'll try that tomorrow. I'm a little worried about fluid running out the bottom of the bench-bled MC, during installation. I'll try using plugs temporarily... BTW: I just updated my signature with year&model of the car. The early Zs had the big reservoir in front!

Had I pulled the master cylinder first, I probably would not have posted the original post! I'm just trying to bleed the brakes on my Z after replacing rear wheel cylinders. The peddle seems to get really firm after what seems a short distance, and I wasn't seeing any level change in the rear reservoir (after pumping). (I had loosened the dvr-side-rear bleed-valve and run a tube into jar with fluid.) So, having just bled the clutch, which didn't work until the master was primed, I assumed the problem would be a dry - possibly pitted - MC, but that doesn't look like the problem. So I'm still troubleshooting. Any voices of experience will be appreciated!

w3wilkes, Thanks for this thread! I really didn't want to spend $450+ for left and right wheel cylinders, and this post gave me the courage to go with the later-model cylinders. I replaced the old "hard-lines" with new (20inch) which wasn't too expensive (about $6 each) or difficult to bend. For the record, my hard-lines don't do a tight 90deg turn. They come out of the cylinder and do a tight "U" turn then do a gentler 90 toward the front. Thanks again!

Thanks Folks! I need to get "her" back on the road before I can start testing these ideas. First the carb-bowl gaskets need replacing (fell to pieces while un-sticking float/valve.) After addressing/replacing tires and brakes, I'd like to have suspension looked at. I used to live close to a German mechanic (might have been "Hanz") in West Covina CA, USA - I thought he was very good, but that was 15+ years ago! Anyway, I'll try to post back if I find the cure for the wheel-hop.

Hi, I have a 240Z that, when it was being driven (10 yrs ago) had a terrible rear wheel hop/bounce at fwy speeds. As i recal the wheel was balanced more than once. I believe it's always the driver-side rear that hops. If the problem is not the tire/wheel then Must it be half shaft universals? Is it possible the half shaft needs balancing? BTW: i just got it running today using gas out of a jug. Tires are all flat; I'm hoping gas tank Isn't full of rust!