AutoX_Z Posted August 19, 2008 Share Posted August 19, 2008 I know that there were some changes from the series II to series III Z's, including a new tranny design and the rearward movement of the rear end by 35mm. What I do not know is what all was included in the movement of the rear end (as far as mounts, suspension, brakes, etc.) and what improvements were made to the tranny. I am considering buying a clean '71 with a '72 parts car. I want to eventually use the car for autoX/track days, and am interested in making a great handling car. I have been looking for a rust free '72, but this '71 looks (from pictures) pretty decent. 1.) What parts were moved in the switch to the series III cars? How was the trans revised or improved? 2.) Do the improvements made to the Series III cars make a noticable difference in handling/driving/maintanence? 3.) How much work would be involved in swaping out the noted '72 parts into the '71 to effectively make it a series III? 4.) Would it be easier, or would I be better off, to just wait till I find a really clean '72, rather than building a '72 out of a '71? Any help with these questions would be much appreciated. I have not went to look at the cars yet, as they are about 3 hours away. However, I would like to know what to expect when I get there. Thanks! Quote Link to comment Share on other sites More sharing options...
Dayz Posted August 19, 2008 Share Posted August 19, 2008 Auto X From what I have seen: Series I is 70-71 Series 2 is 72- very beginning of 74 Series 3 is 74-78 For your diff mod, You will need the driveshaft, the mustache bar and the front diff mount from your 72. Not sure if you need the front mount. The remaining is the same from what I recall. I have done it Quote Link to comment Share on other sites More sharing options...
AutoX_Z Posted August 19, 2008 Author Share Posted August 19, 2008 As far as the series thing, I was referring to the changes in the 240 specifically, as noted in the Production Changes 69-73 section at http://zhome.com/. So, if I pulled the driveshaft, mustache bar, and front diff mount out of the '72 they should just bolt up? Or would I need to fab something up? Thanks for your help. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 19, 2008 Share Posted August 19, 2008 So, if I pulled the driveshaft, mustache bar, and front diff mount out of the '72 they should just bolt up? Or would I need to fab something up? Thanks for your help. They'd just bolt up. No special fabbing required. Quote Link to comment Share on other sites More sharing options...
Soundmasterg Posted August 19, 2008 Share Posted August 19, 2008 I know the transmission mount is different on the '72 as compared to the series 1 stuff, but I'm not sure between the '72 and the '71. I think they changed the transmission for the '72 and the mount mounts to the car in a different spot. If I was going to do all the work to swap things around, I'd just go to a 5 speed myself. Greg Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 19, 2008 Share Posted August 19, 2008 I know the transmission mount is different on the '72 as compared to the series 1 stuff, but I'm not sure between the '72 and the '71. I think they changed the transmission for the '72 and the mount mounts to the car in a different spot. If I was going to do all the work to swap things around, I'd just go to a 5 speed myself. Why are you bringing up motor and trans mounts? The motor mounts are the same, the trans crossmember is different but the mount is the same and in the same position. The one thing that is different is the transmission and it's shifter mechanism. If you have the older style trans when you swap to the newer style the shifter won't come straight up through the hole, you have to make a new shifter or cut a bigger hole in the floor. But that is all off topic. Quote Link to comment Share on other sites More sharing options...
AutoX_Z Posted August 20, 2008 Author Share Posted August 20, 2008 Actually, Greg wasn't off topic. I did ask about the differences in transmissions. Maybe I need to ask my questions more clearly... Is the new transmission and shifter mechanism for '72 better than the one in the '71 I am going to look at? I can not find specs for comparison, and I haven't driven either model year. Does anyone know if the longer wheelbase of the '72 is better for handling and weight distribution because of the repositioned rear end? Thanks for everyone's help so far. Quote Link to comment Share on other sites More sharing options...
AutoX_Z Posted August 20, 2008 Author Share Posted August 20, 2008 Jon, Can you describe the modifications needed to make the newer trans fit in a '71? On the engine side of things, I am wondering if the trans will bolt right up since the engine has not changed. As far as the shifter goes, how much will need to be cut out of the floor? Quote Link to comment Share on other sites More sharing options...
Dayz Posted August 20, 2008 Share Posted August 20, 2008 Transmission is a direct bolt in, just re-use the transmission mount/crossmember (there are 2 styles). I didn't you had to open-up the shifter hole but you must be right. Then use 72 driveshaft, front diff mount and rear mustache bar, very easy and straightforward swap. The wheelbase doesn't change from 70-78 Zcars, just the angle of the halfshaft. Get under that car and start disassembling, you will understand. Quote Link to comment Share on other sites More sharing options...
johnc Posted August 20, 2008 Share Posted August 20, 2008 There were two transmission used in the early 240Zs. The first was referred to as the "A" box and has a separate, bolt on bellhousing and the "monkey motion" shifter. These were replaced (sometime in 1971?) with the "B" box which has an integrated bellhousing and different tailshaft and shifter. Regarding differential position and performance, the early more forward position should theoretically provide a little better balance and reduce yaw inertia. I experimented with diff position on my 2,150 lb. race car and didn't notice any difference in lap times. I know of someone who did notice a difference in their 1,913 lb. autocross car and they currently run the diff in the forward postion. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 20, 2008 Share Posted August 20, 2008 Actually, Greg wasn't off topic. I did ask about the differences in transmissions. Maybe I need to ask my questions more clearly... Nope you asked fine, I just need to read a little bit. Sorry Greg. This thread over on classiczcars.com shows my shifter mod, and talks in more depth about the issues you'll come across: http://www.classiczcars.com/forums/showthread.php?t=24759&page=3 John referenced the potential for better handling with the diff forward. The key here is the U-jointed axles don't like the angularity that the forward diff mount gives. Nissan had vibration issues and lots of U-joint replacements, so they moved the diff back on the later cars. If you want the diff forward, a solution (other than replacing U-joints more frequently) is to run CV's. There aren't too many people messing with CV's for R180s. zcarnut has done some experimenting with CVs and has posted here before about it, and http://www.wolfcreekracing.com makes a very nice bolt in kit. Quote Link to comment Share on other sites More sharing options...
Soundmasterg Posted August 21, 2008 Share Posted August 21, 2008 Hey its ok Jon. I figured you just hadn't read it fully or something. I've heard the shifter on the B 4 speed has a better feel and is stronger. This is the only one I've shifted though since I have a B 4 speed in my '72. I'm swapping a T5 5 speed in though once I figure everything out with the swap. If you were going to go to the trouble of chainging a transmission, I'd recommend putting a 5 speed in unless you want to stay completely original. I believe the Nissan 5 speeds swap in easier than the T5 does. Greg Quote Link to comment Share on other sites More sharing options...
AutoX_Z Posted August 21, 2008 Author Share Posted August 21, 2008 Thanks guys, you're knowledge helped ease my mind. I was beginning to think that I shouldnt even go look at this '71 because I just had to have a '72 with the better(factory) upgrades. My budget will barely support the purchase of the car, much less any modifications. So if I can just pull stuff off the 72 and throw it in the 71, it might be worth it if the car is really solid. As far is the 4 spd Vs 5 spd goes, I already have an '86 300ZX with the 5 spd, so I think I wanna try a 4 spd for a while. Thanks again. Quote Link to comment Share on other sites More sharing options...
AutoX_Z Posted August 26, 2008 Author Share Posted August 26, 2008 Anyone know the difference in weights of the "A" box and "B" box trannys? Quote Link to comment Share on other sites More sharing options...
johnc Posted August 26, 2008 Share Posted August 26, 2008 Anyone know the difference in weights of the "A" box and "B" box trannys? I think they are within a pound of each other. I weighed them both years ago and the difference was so insignificant that I can't remember... Quote Link to comment Share on other sites More sharing options...
AutoX_Z Posted August 27, 2008 Author Share Posted August 27, 2008 Ok, thanks. Quote Link to comment Share on other sites More sharing options...
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