240z to 280z? tranny swap

[greenz]

welp, my tranny just busted and i need a new one. i want to know which transmissions i can use with my stock drive shaft and rear end. i thought it was a straight bolt in, but i've heard that i will need a different throwout bearing or longer driveshaft. i have a 1970 240z with a '77 280z engine in it and a stock 1970 driveshaft and r180 diff. . any help is greatly appreciated!

pleease respond to this thread or with an e-mail! thanks!

[2ManyZs]

Any four speed should work, the only difference is the shifter linkage. The B model transmission is a little better (stronger), the shifter linkage was changed in about 72 to the B model.

One difference is the gear ratio between the 240 B model and the 280 B model. I'd have to look it up but I can give you the gear ratios if you like. The 5 speed would require a little work if you want to go with that. You would need the 280 driveshaft and you would have to change the yoke on the rear.

[greenz]

thanks for the reply, 2many! is the yoke something that i can unbolt easily from the 280 doner car? is there anything else that i need to take from the doner 5-speed car? it seems that the only trannys i can find at the junk yard ar in ZX's and not Z's. would i be able to use a '79 thru '83 zx transmission with my '70 r180? thanks for your help!

[2ManyZs]

Oops, I forgot the zx's. The trans from the 79-83zx will work, just don't get the T-5 trans, you will end up with a lot more work.

The yoke should be easy enough to remove, you might check it before you take it off to see if it bolts up to the driveshaft. I don't think the 240 yokes and the 280 yoke are the same, the flange is a little different. All you will need is a socket to fit the pinion nut. If you get the 5 speed and the driveshaft to go with it you will need a yoke off an R-200 from the other car. Of course if you just wanted to put another 4 speed in you won't have to do this. You could look in the For Sale here on the site, you might be able to find another 4 speed to use until you get all the parts together to do a 5 speed swap. A 4 speed should be pretty easy to find, it's the 5 speeds that are a little harder to get since everyone wants to put them in their 240's.

[Royce]

Okay, wait just a minute!!!

I have a series II 240 that had an early style trans. I agree that the early trans are junk and that the later style are stronger. But when I changed to a Z 5-speed all I needed to do was grind out the shifter hole in the trans tunnel and notch the console. I used my stock clutch/flywheel, throwout bearing & sleve, and clutch slave cylinder. You should be able to use a late style trans ('72 -'83 4 or 5 speed) without anything but the modifications I mentioned. When I later changed to a L28 no drive line modifications where needed either!

If you change to a R200 diff then you will need a different drive shaft, amongst other things, and potentially a different yoke or diff flange to make it work.

I personally think the Z 5-speeds are a waste of time. I would use either a later Z 4-speed or go to a ZX 5-speed. The Z 5-speed just has to big of a gap between 2nd & 3rd gear (most used on track or autocross.) I am currently saving my pennies for a ZX 5-speed.

That's my thoughts! Mileage may vary!

[greenz]

thanks for the reply royce. i am going down to the junk yard tomorrow to get my ''new" zx tranny. im glad that i dont have to swap out my stock components that are still good. when i have the money i plan to up grade to an 83 zx drivetrain w/25% overdrive and an lsd r200. but for now, your answers have me on the road again! thanks!

[Royce]

One more small detail... I used a later style rubber shift boot and the matching frame to properly seal the trans tunnel. The original early 240 style would no longer work after grinding the trans tunnel hole. It was a bolt-on (screws actually) modification.

Glad to share the info! Have fun!

[2ManyZs]

I stand corrected. Everything I ever read said when swapping to the 5 speed you needed the driveshaft from the donor car, but if it works without it that's even better. Maybe I shouldn't believe everything I read until I try it, I hadn't done a 5 speed swap into a 240 yet, I have the 240 in pieces so it doesn't need the 5 speed yet. I guess now I will have an extra 280 driveshaft I don't really need.

[Royce]

Well I can see why people suggest that. The transmissions are different lenghts, the new type are shorter. But when I did the swap there was still plenty enough drive shaft to work with and I drove the car daily for years without any problems because of the difference and I beat on my car pretty hard back then. And since GreenZ also is going from early Z 4-speed to later 5-speed it should be the same experience.

The only thing I am not sure about is that maybe the later 4-speed & later 5-speeds are different lengths. I will be taking apart two parts cars in a couple weeks, one with later 4-speed and one with later 5-speed. I will have to compare the difference and report back.

Mileage may vary! Have fun!

[2ManyZs]

I believe the later driveshaft is little longer, perhaps they recommend using the later driveshaft so that the slip yoke is more fully engaged on the output shaft of the trans. I have both driveshafts and the difference is not easy to see, you almost have to measure them. I guess if the splines weren't fully engaged you could possibly end up with a little wobble and it would give the driveshaft a bit of a vibration. Of course if the stock driveshaft works the point would be moot, most people aren't going to thrash a street car enough to notice.

I wish I had access to a junkyard that had more older model Z's. It would make for it easier to try different things to see how they work. I'd like to find a diff out of the later model 200sx turbo, as they have a limited slip and I believe about a 3.9 or 4.11 ratio. There weren't a lot of those cars on the street so finding one in a junkyard is not going to be easy.

Of course if greenz is going to an R-200 the longer driveshaft would already have the right yoke to bolt right up to the driveshaft. Then all he would have to do is change the mustache bar and the lower suspension crossmember to clear the larger R-200.

[Royce]

Yes, the 280 drive shafts are longer but it is not necessarily because of the different style transmissions. I didn't experience any vibration in the drive line and I was driving like a maniac back in those days. I think the splines on the drive shaft and trans are long enough that you still have plenty of contact.

I know we are going in a different direction but, actually there is more to the R200 swap than that.

First, I would like to say that I don't think the R200 swap is a good idea for the average Z -car. I did mine a long time ago because I didn't know any better. I wanted to change diff ratios and thought my R180 was going bad but it was a combination of diff mounts and mustache mounts that where the problem. I wish we had this type of technical communication back then, could have saved me lots of time and money. The R200 is far more robust than the R180 but it comes at the price of weight. I could tell the difference when I changed mine. I think it is really only necessary if you have a V8 or tweaked turbo motor with 300+ HP. I have a R180 that I plan on putting back into my car.

When I changed mine I had a 280Z parts car that I could use for parts, which made it very easy. I was told the same mustache bar can be used if you just turn it around. While that may be true the R200 mustache bar is beefier and I suggest using it. Also, the R180 mustache bar would need to be modified to mount the R200 which has larger mounting bolts. Second, yes you would have to change the lower crossmember that connects the suspension control arms behind the diff to make room for the larger R200. This is when I changed to the 280Z drive shaft because the R200 and R180 diffs are different lengths. You cannot use the original drive shaft anymore here. Also, the strap that holds down the front end of the diff may not work. I have heard of people getting it to work by cutting half an inch off the bolts that mount the front of the diff and installing them upside down. If you don't use the strap you will tear the front diff mount into two the first time you touch the gas peddle. I just installed a solid front diff mount and was done with it. Also, half shafts may be an issue, I have heard different stories on this. I had the 280Z R200 half shafts laying around so I used them. I still have my 240Z ones and will compare them with a 280Z that I am going to be taking apart in a couple weeks.

That's all I can think of off the top of my head. Feel free to let me know if you have any questions or corrections.

[2ManyZs]

I definately agree that if anyone is not going to build some serious HP an R-200 is probably overkill. I know the ITS racers are putting some pretty good HP numbers through their 180 rears with little or no difficulty. The weakest link then becomes the factory limited slips if they choose to run them. When they run the rears "locked" then the weak link ends up being the u-joints and the stub axles if the stub axles were never serviced.

If you are interested did you know the early Nissan 4x4 pickups have the R 180 diff in the front with something like a 4:37 ratio? I think the only thing that needs to be changed is the flanges to bolt them into a 240. Something worth looking into, with a 5 speed a 4:37 would be just about the right ratio for cruising with the overdrive.

You are right Royce, I believe the change over to an R-200 is probably not the best thing to do on a street car, not only from all the parts you need to change but they are an anchor. I never looked forward to taking mine out of my 280 while laying on a creeper!

I know we've gotton a little off track here but at least greenz can decide how far he wants to go with his project.