240Z/260Z/280Z auto to 4/5 speed swap

[Arne]

1.) You need a service manual of some sort if you're going to attempt to do this kind of work. That should absolutely be your next purchase. Period.

2.) Pressure plate to flywheel bolts should be torqued to 12-15 ft. lbs.

3.) For those of us in the US, left is driver, right is passenger. Always.

[Datsun_Mike]

Okay so I bolted up the tranny and everything slides right in except for the tranny x-member. Did I miss something because the tranny x-member will not bolt up. And I will need to cut a bit of my shifter housing off. I'm using a 280Z 4spd tranny. I think I'm going to need custom tranny x-member made or something. What a headach!!! Sorry for hijacking this thread Arne.

[Arne]

Since I now have a second 240Z that is a manual transmission car (a later '71 that I'm parting out), I have had a chance to learn a bit more about the differences, other than what I mentioned in the original article. As is the case with the original article, the details here are based on early 240Zs. Some of this will likely apply to later cars as well, but YMMV.

Bodyshell - I have found a few other differences in the bodyshell, in addition to the presence of (or lack thereof) the bracket for the clutch hose on the framerail. One is a mounting point on the inside of the firewall above the throttle pedal for the "kickdown" switch. (More on the switch itself later.) Manual transmission cars do not appear to have this mounting tab. But the manual transmission cars do have a rectangular clutch pedal stop (about an inch high) on the firewall, that is missing on some or all automatic cars. Also, the automatic cars have four holes with captive nuts at the four corners of the shift lever opening (to retain the automatic shift selector) that the manual cars don't have.

Wiring - Both the engine compartment and dash harnesses are different for the automatics, the rear body harness is the same. The dash harness has extra leads for the "kickdown" switch, as well as an extra dash illumination bulb for the shift selector. In the engine compartment harness, the lead from the ignition switch to the starter solenoid is routed through a neutral safety switch on the automatic before it gets to the starter. (These are the leads that must be connected together.) The reverse light switch leads may have different connectors than on a manual car. And lastly, there is an extra relay on the left inner fender in front of the coil and near the radiator support. More on this below.

Mechanical - Under the hood, the automatics all had a radiator with integral transmission cooler in the lower tank. The fittings can be ignored or capped off when the manual transmission is installed. (In fact, these days many aftermarket replacement radiators on the market are fitted with the cooler so that they can be sold as one-size-fits-all.) There is also an extra vacuum fitting on the balance tube, that goes to the transmission modulator. This port will need to be plugged or capped off.

And then there is the ignition. The automatics came with a dual point distributor, instead of the single point unit on the manual transmission cars. And this is where a whole lot of the differences are related. You see, the dual point unit was not designed for performance or reliability, it was designed to give more ability to vary the timing advance curve. Under normal driving, one set of points would be used. Under full throttle, the above-mentioned "kickdown" switch (which actually has absolutely nothing to do with transmission kickdown) energizes the relay near the coil, which switches the ignition to the second set of points. That second set has a slightly different static timing, which effectively changed the advance curve.

This could cause problems during ignition swaps, if not taken into account. It might be considered less than optimal for the ignition to cut out whenever the throttle was opened wide, which could happen if the ignition were re-wired incorrectly!

[Surfsup]

i was wondering how much did all this cost for the swap ? and was it really worth it ? thanks.

cause i'm deciding to buy a 240z auto cause it has some rust . or should i just wait for a 4spd.? man im impatient

Thanks for the thread builder. it will def help if i decide to get it

thanks man.

[a7dz]

Arne;

Mechanical - Under the hood, the automatics all had a radiator with integral transmission cooler in the lower tank. The fittings can be ignored or capped off when the manual transmission is installed. (In fact, these days many aftermarket replacement radiators on the market are fitted with the cooler so that they can be sold as one-size-fits-all.)

I could not find a new manual only radiator. Settled for auto because it is new and less cost then getting mine redone. But, will keep this core for a while incase someone needs it.

[Arne]

i was wondering how much did all this cost for the swap ? and was it really worth it ? thanks.

cause i'm deciding to buy a 240z auto cause it has some rust . or should i just wait for a 4spd.? man im impatient

Thanks for the thread builder. it will def help if i decide to get it

thanks man.

Cost? - That can vary a lot. Many of the parts needed will be used. So it depends on how much you can find the parts for. In my case, the 4 speed came with the car. All of the various used parts cost me less than $200 total. New clutch pieces probably another $200. Call it less than $400 for the whole job.

Worth it? - That also depends. If you want a Z with a manual transmission, there are only two options. Buy a manual car, or buy an automatic and convert. If you can find a manual car in equal condition for no more than $500 more than an equal automatic, it's a wash.

But frequently, the automatics are considerably cheaper than an equal condition manual car. Also, many of the automatics are in much better condition than a manual car, as they seem to have had much easier lives.

If you are looking for a restoration project, you should probably wait for a manual car. But if you want a Z for a fun daily or weekend driver, converting a nice automatic can be a viable option.

[Surfsup]

Cost? - That can vary a lot. Many of the parts needed will be used. So it depends on how much you can find the parts for. In my case, the 4 speed came with the car. All of the various used parts cost me less than $200 total. New clutch pieces probably another $200. Call it less than $400 for the whole job.

Worth it? - That also depends. If you want a Z with a manual transmission, there are only two options. Buy a manual car, or buy an automatic and convert. If you can find a manual car in equal condition for no more than $500 more than an equal automatic, it's a wash.

But frequently, the automatics are considerably cheaper than an equal condition manual car. Also, many of the automatics are in much better condition than a manual car, as they seem to have had much easier lives.

If you are looking for a restoration project, you should probably wait for a manual car. But if you want a Z for a fun daily or weekend driver, converting a nice automatic can be a viable option.

Thanks Arne. I think i'll convert the auto then. im not looking for any restorations. thanks and ill use the guide here that u made. wish me luck! haha :laugh:

[JER240Z]

Arnie - Thanks for the great article - I am just getting started - Question - did you have to Drill the hole in the firewall for the clutch master actuating rod to the clutch pedal? In my 73 240 the bolts are there for the master but no hole for the rod - If so what size? Thanks

[Bobby_Lee]

Here is a link to some pics that may help while you're working the swap.

http://www.classiczcars.com/forums/showthread.php?t=20794&highlight=auto+manual

[DC871F]

What a thread, Im just about to start the conversion.

I had a guy who claims to be a Z expert, say I needed to cut the drive shaft to get it to fit in between the manual gearbox and the diff. I guess this is not the case since no one has mentioned it.

Thanks for all the info

Edited August 29, 2008 by DC871F

[Arne]

If all you are changing is the transmission type (and not converting to the T5 from the late ZXT), the driveshaft you now have from your automatic will work fine.