zcarnut

If the problem is mechanical in nature, then applying a very lightweight oil (available at a jeweler’s shop) to the meter movement will usually get you going again. If the problem is electrical then you may have a more of a challenge. The 240Z's tach used a simple two transistor "one-shot" circuit to drive the meter movement. I made a schematic of the circuit and posted it on the Classic Z Car forum. 240Z tach schematic. The transistors are still available. The later 260Z and 280Z tach's used a special Hitachi IC to drive the meter and it is NLA. I have taken apart lots of tachometers and my recommendation is always just to replace the tach with a used (but working) one.

A bigger brake booster will not reduce the stopping distance of your Z. All the booster does is to reduce the pedal effort by increasing the force applied to the master cylinder. Brake boosters are carefully chosen for their application. A bigger booster than what is needed will only allow you to lock the wheels up more easily when braking, and that is not the best (or safest) way to stop a car. Another issue is that the brake booster needs a certain amount of time before maximum boost is applied. Remember you are dealing with the movement of air to one side of the diaphragm in the booster. The larger the booster the longer this time is. This is why you never see a booster on a true race car. Racing brakes need to develop master cylinder pressure as soon as the driver presses the pedal. The only time it is OK to go bigger is when you are increasing the diameter of your master cylinder. As increasing the diameter of the master cylinder will result is a increase of pedal force (for the same amount of fluid displacement).

The change occured mid-summer in 1972, so only the 1973 L24's have the 9mm diameter rod bolts.

The Datsun 810 was built from 1977 to 1980. The 810 evolved into the first generation Maxima which was produced from 1981 to 1984. Everyone assumes that “810 = Maxima†which is not true. The Maxima was almost a total redesign and none of the suspension parts, body parts or interior parts from the 810 will interchange with the first gen Maxima. Only the drivetrain remained about the same. However even the L24E engine was changed when the Maxima appeared. The (1977-80) 810 L24E engine has the same crankshaft as the L24 [240Z] engine, a 25lb flywheel, 9mm rod bolts, and a N47 head similar to the one found on the later 280Z except for the smaller exhaust valve. The L24E engine in the (1981-84) Maxima had the following differences: the N47 head was changed from a “dome-wedge†shape to a “wedge†shape (quelch combustion chamber), the flywheel was lightened to 17.5lbs and the rods and crank were changed to accommodate a thinner connecting rod journal and the rods used the 8mm bolts.

It's been a few years since I did this, but it's a good weekend long job. You will need to swap out the front suspension crossmember and this requires supporting the engine with a cherry picker. I also recall having to change the steering column as the diameter of the splined shaft to the rack is different but we were going from the power re-circulating ball box to a manual rack-and-pinion.

The torque spec is not in the FSM. The text “How to Modify Your Nissan/Datsun OHC Engine†by Frank Honsowetz has the cam tower bolt spec at 10 to 13 ft-lbs.

Don’t give up on the 280ZX CV axles completely, Brian. I think the easiest solution to the shaft length issue may be in the CV-axle-to-companion-flange adapter design. The reason that the adapter has to be so thick (at least an inch) is because of the protrusion of the spring holder on the sheet metal grease shield cover. If you use the Z31 grease cover you can make the adapter shorter (maybe three-quarters of an inch) or if you have a flat cover the adapter can be even shorter. A flat cover could be easily constructed by hand and glued to the outer CV axle housing. Speaking of the pre-load spring, I recall someone on another forum who removed the springs altogether. Apparently without problems(?). He concluded that since the free-play range (on his axles) was so small the spring did not serve any useful function.

It's the stock Nissan part for the 720 4x4 truck CV axle. They're even harder to find than the Z plates.

(I think someone wanted to know this.) 280ZX turbo CV axle boot kit: Inner Beck-Arnley 103-2280 Outer Beck-Arnley 103-2282

I got mine from The Z Barn off some bad (cores) Z31 axles.

No, it’s not that easy. The tripod bearing is secured by the splines. If you remove 3/4 inch of the splines on the shaft you would need to remove the same amount from the inside of the tripod bearing piece. The spline length is just over one inch long. That would give you only 1/4 of splines to hold the tripod bearing piece. I think you need to examine an actual 280ZX CV shaft in detail before you consider modifying it.

Actually it is the boot band itself which holds everything together! The boot band has an inner lip that prevents the tripod bearing from leaving the inner housing. Since the boot is made with the band, you can't change one without changing the other. Definitely not designed for easy disassembly. BTW, the 1981 and 1982 280ZX FSM says that CV axle disassembly is not possible and that the entire shafts must be changed. However, the 1983 280ZX (and Maxima) FSM does have the CV axle re-building instructions.

Good idea, but it won't work. The splined sections have a slightly larger OD than the shafts and make a gradual taper into the axle shaft. This reduces stress where the splined section meets the smooth axle. Standard "good engineering" practice.

I’ll warn you in advance. The CV axles are extremely hard. Even cutting them apart will be difficult. Welding such material is not for an amateur. Hardened steel is more likely to lose its strength (and hardness) during welding and you risk introducing cracks in the axle due to the heat of welding. Driveshafts are made from a different material, and are far easier to modify. I decided to drill only ¼ inch into a set of CV axles for a roll pin to secure the tripod bearing. I did not trust the “swegged†method used in the 280ZX turbo CV axles. (The Z31 axles went to a much better “snap ring in a grooveâ€.) I got it done, but I ended up breaking two $75 hardened drill bits in the process. The CV axle inner joints can be re-built. I have done several sets. The inner boot metal band must be cut off to remove the inner boot. Tip: The FSM tells you to cut it in the wrong location! You need to cut the band just over the top of the o-ring groove. This will cause less damage to the tripod housing (which must be re-used). You get a new o-ring in the rebuild kits (I use Beck-Arnley) so you can cut into the old o-ring without worry. To install the new boot I make four pairs of saw cuts (about an inch apart) around the perimeter of the top of the band. These “tabs†are then pressed (or hammered) down, securing the inner boot. The exposed groove is then filled with RTV. It helps to have a hydraulic press to clamp the assembly down while you are bending the tabs. If I ever re-build any more CV axles I will first make a collar on my lathe with a tapered inner surface that fit over the band. Then with a press I hopefully will better able to duplicate the factory method and its appearance.

The 280ZX started out with a power-assisted re-circulating-ball steering box with the standard accompanying pitman arm, idler arm and drag link (or track rod) pieces. This was done because the 280ZX used the Datsun 810's (1977-80) suspension set up (both front and rear) and copied the steering arrangement as well. In 1981, when the 280ZX Turbo version was introduced, the turbo housing would have interfered with the re-circulating ball steering box so Nissan was forced to introduce the rack-and-pinion steering configuration. It remained a power assisted unit. The power assisted rack-and-pinion steering was then used in the other non-turbo 280ZX’s as well. When Nissan came out with the low cost, “no-frills” version of the 280ZX (4 speed, manual windows, etc.), they installed a cheaper non-power (or manual) version of the rack-and-pinion steering set up. BTW, all three 280ZX steering systems require a different lower front crossmember. An interesting fact of the 280ZX (and 810) steering systems is that early power steering pump was actually supplied by Saginaw (then a GM owned company). Nissan eventually switched to a Japanese vendor (Atsugi) on the later 280ZX’s.

Only difference is the length of the center axle shaft. As Jon mentioned, the 300ZX ones are longer. The sheet metal grease cover on the 300ZX CV axle has a smaller dimple than the 280ZX Turbo CV axle. This dimple houses the pre-load spring. The smaller dimple cover can be used on the 280ZX axles and this makes them easier to install on the earlier Z cars.

I think you should rephrase your question so it says “Experiences with a Lightweight Flywheel on Z's?â€. You can have a lightweight flywheel made from steel or aluminum. Steel is a better choice for a street car because I have seen aluminum flywheels wear around the crankshaft bolt holes. This causes the flywheel to become slightly loose over time (which causes more wear). You must keep an eye on the torque setting for the mounting bolts and routinely check them. That being said, I have a 10lb HKS steel flywheel on my 260Z (3.1 liter engine, triple carbs, big cam, 3.70 diff) and it is great! Throttle response and acceleration is much improved and it is very streetable. The only difference I noticed was that the drop in rpm between gear shifts was increased, but this is easy to mask if you get into the habit of “blipping†the throttle when you dis-engage the clutch. No way I would ever go back to a heavier flywheel.

2003z is correct. This was discussed on the Classsic Z Car Club Forum recently: The early Z car seat belt mounting bolts are SAE thread and not metric thread. This is due to the US DOT standards in effect at that time. Quoted from 571.209 Standard No. 209; Seat belt assemblies: ...Seat belt assemblies designed for installation in motor vehicles equipped with seat belt assembly anchorages that do not require anchorage nuts, plates, or washers, need not have such hardware, but shall have 7/16- 20 UNF-2A or 1/2-13UNC-2A attachment bolts.... You could either use the approved SAE bolt which has been already tested and certified by DOT or you could use your own bolts but you must summit your test data. Generally, it is cheaper and safer to do the former.

It's not to "cool" the throttle body, it's for heating it... I asked an automotive engineer (he worked for Ford) this same question a few years ago and he said it is only done to reduce the carbon build up on the throttle blade. It had nothing to due with emissions or driveability. Apparently carbon is less likely to collect on a heated surface. Such deposits can result in throttle sticking and claims of “unintended accelerationâ€.

Nissan used course thread pitch on the fender attachment bolts, which means a 6mm diameter bolt will have a “pitch†of 1.00mm, and an 8mm diameter bolt will have a “pitch†of 1.25mm. The term “pitch†is not really applicable with regards to metric fasteners. Pitch for SAE hardware is specified in “threads per inch†so a bolt with a pitch of 24 has finer threads than a pitch of 18. Whereas for metric bolts the number used is the actual dimension between the threads. As a result a metric bolt with a thread spacing of 1.00mm will have finer threads than one with a rating of 1.25mm. Most of the non-critical bolts on the Z car will have course threads. One exception is the bumper attachment bolts which have fine threads. Most of the critical bolts (suspension, brake mount, etc.) will use fine threaded bolts.

http://www.drivetrain.com/nissian4_5sprwd.html Re: Bent roll pins for the shifter forks: The easiest and best way to fix the roll pin issue is to “double pin†them. What you do is to replace the roll pins with new ones and then drive another (smaller) roll pin through the center of the outside roll pin. If you want a real expert to rebuild your tranny then send it to the Z Barn. The guy who rebuilds their trannys has done over 250 Nissan 5-speeds ones and he really knows the problems and the corresponding fixes.

No. Door striker is the same for the 1970-76 cars.

Because of the different door arm rests and door pulls (and different door trim panels), the screw holes for the door arm rests and door pulls are in slightly different locations between the 240Z and the 260Z. (Actually the doors from 1974 through 1976 are the same.) Just remove the trim panel from the 260Z door and replace it with the 240Z one. Then mark the new locations for the mounting bolts and drill. Use the 6mm threaded “RivetNuts†inserts. BTW, if added weight is a concern then you should be aware that the 260Z door is noticeably heavier than the 240Z door.

No. The ZX ECU only controls the FI. AC system is completely separate.

OK, I’ll chime... The 280ZX compressors are different from the earlier (1974-78) compressors. The ZX compressors have a larger displacement, require less re-circulating oil and the inlet and outlet ports are reversed when compared to the earlier ones. More info: There are two types of ZX AC compressors, an early one and the later one. Difference being the width of the pulley groove. Early ZX compressors use the wide belt like the 1974-78 compressors and the later ZX compressors changed over to a (more modern) narrow belt.