Ownallday

Coming here to give an update and fix for my situation Incase this somehow ever happens to someone else. My problem has been resolved. Took my shift rods to a machinest and had him make the missing notches. I gave him the rods from the 4 speed I tore apart as reference for how far to machine them. Put the transmission back together and can confirm at this time that the shifter now has that satisfying click into gear, feels exactly how my old 280z 5 speed felt so I without a doubt believe the problem has been resolved as it now requires at least some force to get the transmission out of gear and the rubber shift boot is no longer pulling it out of gear. Will test drive the car in a week, if I don't post on here saying the car still pops out of gear then my problem has been resolved.

If you have any bad transmissions and can sell the shift rods I will buy em. Probably best for an early 5 speed since that is what mine is.

Well, gotta bring bad news. The rods from a 4 speed are shorter than that on a 5 speed so it will not work. However I now have rods with the proper distance with the notches for a machine shop to use as reference. However I do see some rods for sale on eBay, exact transmission code as a a 280z 5 speed but I'm not sure if they will actually work since they are for other datsuns

Yes Im aware of that. I have plenty of 4 speeds for dirt cheap around where I live. Gonna pickup a 260z 4 speed transmission up tomorrow and see if those rods will work and what other components like the forks if those would realistically work for future reference. Yes the picture I sent was of the bottom and top side of the same rod. Both sides have one notch. Based on three YouTube videos and my previous 280z 5 speed pictures all these rods should have 3 notches so I'm not sure why this one has 1 notch for two rods.

Seems I figured out what's going on. The transmission was rebuilt and everything looks good until you start looking at the rods. Removed the rods for 1st gear through 4th gear and seems these rods are missing the notches for the detents entirely. My 5th gear and reverse and neutral have notches. I remember my old 280z 5 speed had 3 notches on each rod so I'm not sure why this 280z 5 speed is missing notches. I'm located in Los Angeles. In this case for me, I just need the shift rods to be replaced, I was already kinda figuring the rods or forks was going to be my problem and to my knowledge the rods should be the same for 1-2 and 3-4 on a 4 speed and 5 speed but I could be wrong. My next option would be to have a machine shop just make notches for me but that might be more expensive.

I honestly couldn't noticed if it was on or off throttle. Seemed more like on throttle as I could only get the car to 8mph realistically. I don't think the previous owner of the transmission installed it at least I remember him telling me, said he got a short ratio 5 speed. Yes the plastic cup is fully inserted. Visually doesn't not seem to pop up beyond the rod opening. I can double check tonight. The guy did not include the shift rod with the transmission, I bought this shift rod from someone else parting out a Z with a wide ratio 5 speed. Thing is like I said I used a flat head with the shifter out of the car to push the rod into gear like that, and same thing as the video, no clicking into 1st gear through 4th gear but clicks perfectly into 5th gear, reverse and neutral like in the video. I already cut my trans tunnel for clearance, in the video you can see I have space there.

That is my understanding also. I have detents coming this week. Will lower the transmission and swap them out and see if anything changes (highly unlikely). I will update this thread with the post on what it was after it's fixed. Do you know if a 4 speed transmission has interchangeable parts with the 5 speed? Incase the forks or sliders themselves are the issue or something else that cannot be bought new

Looked into them. My only thing I can probably try at this point is just replace the detents before opening it up which I don't want to do for obvious reasons. By far 1st gear through 4th gear does not lock in place, pretty much like the detent action is non existent. 5th gear and reverse feel great, they lock into place an take a good amount of force to get it out of gear so I already know every gear aside from those will pop out of gear. Yes I have. I also removed the shifter and used a flat head to try an push it into 3rd gear without the shifter and it doesn't lock into 3rd. I can easily slide it out of 3rd gear with the flat head but takes a lot of force or prying force to put it back into third gear. Here's a picture of my shifter and bushings. I think the flat head trick rules out a shifter or bushing issue because it just feels like either the detents aren't going into those notches on the shift rods or something internal isn't allow full movement into gear

I have a manual swapped 240z, a 5 speed from a 280z. I bought the 5 speed from someone who stated the transmission was rebuilt (I can only assume new synchros and bearing). I also have a new shifter bushing and brand new transmission mounts and bushings. My car is currently an MS3 setup and not tuned yet, so I could only drive the car fast enough in first gear. first test drive the car constantly popped out of 1st gear followed by a slight bang. I could not test it in other gears. Got the car in the air, and with the wheels off the ground it does not pop out of any gear. Today I noticed that basically it feels like 1st gear - 4th gear does not seem to fully engage. 5th gear and reverse seem to engage perfectly as there is resistance needed to get out of 5th and reverse gear, but 1st-4th gear has almost no resistance and I can pull it out of gear with my pinky. It almost feels like the detents are either missing or they are not reaching the slots on the shift forks. I provided a video, you can hear 1st gear - 4th gear does not really make a satisfying click into gear compared to 5th gear and neutral. Any feedback on what exactly is the issue would be greatly appreciated. Last Question is in the off chance the shift forks are the issue, could the shift fork rods from a 4 speed be used in a 5 speed? 20260425_174259.mp4

Trying to setup my Jenvey ITB's without a linkage rod. I have seen some people use a throttle wheel for a cable setup that bolts up to the side of one of the ITB's. Does anyone know where I can find something like that? Jenvey does not seem to sell anything like that. I would prefer that setup as it keeps everything really clean without a linkage rod. Thank you!

Thank you, just confirmed today that the itbs will bolt right up to the canon manifold no problem. Wanted to use this manifold since the manifold grabs vacuum from from every port so I can get a better MAP reading for tuning.

Good idea, I will send get in contact with them. Thanks!

Hello, I have triple Weber dcoe 40 at the moment. I plan on going fuel injection itb setup. My question is will the triple webers canon intake manifold bolt up and work with Jenvey ITBs (40s) or ITBs in general or is another manifold required?

Sounds like the 3.9 is the way to go then. my 280z typically ran at 3k rpm at 65 mph and it did not bother me at that rpm.

Thanks for the response, so a 3.9 would be a good option?

Hey guys, I recently sold my 1978 Datsun 280z and picked up a 1973 Datsun 240z. I plan on doing a manual swap with a 280z wide ratio 5 speed as I have a rebuilt one. Down the road I plan on doing a NA L28 build and push at least 250hp+ from it with an ITB setup but for now the L24 will have to do for the next two years. I live in California and the car will mostly see city driving, freeway driving but will also see the canyons pretty often in spirited driving and maybe a track day once every year. I am wondering what would be the best differential to pair with the type of driving I will do and my engine goals. I also plan on doing an LSD conversion for whatever diff I get. (Also if anyone can specify if they know what gearing a stock automatic 1973 240z came with would be appreciated).

Will do, I think it'll be fine I barely tightened the bearings about a quarter turn and used really good bearing grease. Just to be safe however you wouldn't happen to know what the max temp the bearings should be at?

We can finally celebrate! My steering wheel shaking is gone! I re-checked every single bolt in the front suspension (for the third time), removed the steering knuckles even and tightened the bolts for the bolt joints. Removed my wheels and removed all the rust on the hubs and backside of my wheels. However I think the fix was the front bearings! Even though I followed Nissans procedure for the wheel bearings I think they might be too loose for my suspension setup with hind joints and poly bushings. I tightened the nuts for the front bearings just a little more making sure the hub can still spin nicely obviously. All this and steering is solid! Crazy to think I went though two sets of bearings following Nissans procedure only for it to be the problem haha. To everyone with modified suspension and getting wheel shake, tighten the bearings! Thank you to everyone for helping! appreciate all of your for the help!

My lug nuts are tapered. I'm using the same lug nuts my friend used when he was running these wheels and he had no shake.

Quick update. Adjusting the tire pressure had no change or effect any where between 25 psi and 35psi with the steering shake. I finally got my wheel spacers that are also hub centric and no change to the vibration either. I went to double check for play and noise when moving the hub and even with the tire off I get a small clunk/thump sound when moving up and down. My wheel bearings and ball joints (Part of the TTT control arm) are maybe only two years old at best with less than 15k miles on both. You guys think the hubs could be bad? I am almost at the point now where I am just going to order TTT hubs with new bearings. Two videos of the noise below. Yes I know the surface rust on the rotor looks bad btw. Going to fix that soon. 20240409_100445.mp4 20240409_100418.mp4

I've tried anywhere between 30psi to 35psi and no difference. To the eye and feeling with my hand there are no noticeable flat spots. And I've already tried balancing the tires at work at least 10 times. One thing I will say is on the driver side I can here a slight click or tap noise when moving the tire in the same manner if you were to check for wheel bearings. However I cannot get that noise with the wheel off the car. This might be leading me to believe that the wheel studs might be ever so slightly too long and the lug nuts aren't 100% pressed against the wheel to the hub. The car has extended studs and were cut slightly but maybe they weren't cut enough for the wheels I have. I have a 5mm spacer coming so I can check when that gets here.

Thank you, yes I have psi right around 32 psi. I'll try an reduce tire pressure and see what results I get with that. I run a 225/45r15 and I have the technotoytuning control arms and tension rods. Maybe the combination with higher tire pressure and my hankook Rs4 the tire tread catches into the road surface aggressively? Anyways I'll reduce it to 25psi and see what the results are next week. Thanks for the tip.

Noted, going to be removing the wheels and looking into everything sometime next week. My wheels look like the lug holes have been repair sometime in the past I'll have to post some pictures of that. The only thing I have yet to replace in the front at this point is the wheels and tires (going to swap wheels and tires with a friend in two weeks if it's still isn't resolved), the steering rack, and the wheel hubs. Still haven't got rid of the vibration to this day. Also even though I replaced my struts and have lowering springs, not sure if it can still be that because if the road is perfectly smooth the wheel doesn't vibrate at all, but if there is any very minor road imperfections is when it vibrates at nearly any speed so it varies with road surface.

I know Z cars are lug centric and not hub centric. If the wheel is less than 73mm then in that case means the wheels wont sit completely flush against the hub? Or am I missing something.

Thought I would give a continuation and update to what I have found. I may have found the solution to my problem! Years ago my friend gave me his Enkei 92 Wheels from his Datsun 240z and this is what I have been running since then. I have just discovered the 280z hub bore size is 73mm while the Enkei 92 wheel bore size is 72.6mm!!! My wheels are not 100% flush against the hubs is what it looks like I am seeing here! After replacing nearly everything I think this might be it, but what is confusing is other people have used these wheels without problems apparently like my friend. Can someone give any insight? I might buy a hub centric wheel spacer to make sure this is the problem before buying other wheels as I just bought Watanabe wheels but they don't fit currently over my brake calipers and even then it shows Watanabe wheels are 63mm or 70mm so that's saying these wont fit either?