Swapping in a Trans from a 240sx...advice?

[Darbji280z]

At the end of the summer last year, I came to the conclusion that the syncros in my 4-speed trans were going bad. And I've decided to go with the 240sx trans.

I am aware that my bell housing needs some modification to fit the sx trans. I've already talked to a local machine shop. The driveshaft will probably have to be shortened. I've done a great deal of research and I'm pretty confident in my ability to make this work. But I was wondering, if there is anyone else out there that's done it, do you have any advice?

[Arne]

Hey, Darb, welcome back.

I don't know much about the details of going to the 240SX transmission, but I do have a question. Considering how simple and straightforward swapping a 280ZX 5 speed into your car is, what prompted your decision to do the much more difficult job?

[ezzzzzzz]

The 240SX (or KA) transmission is superior. Having built many early transmissions and finally completing this conversion for myself I can say it's worth the minor trouble. Head over to www.hybridz.org and search for the 240SX or KA swap. There's plenty of documented information.

[Carl Beck]

The complete article by Steve Heimsouth, related to the 240ZX Transmission swap - is hosted on the Z Car Home Page

http:ZHome.com in "the Z Car Technical Library" section.

The direct URL is:

http://ZHome.com/ZCMnL/tech/240SX5spd/transmission.htm

FWIW,

Carl B.

Edited March 7, 2009 by Carl Beck

[Carl Beck]

Considering how simple and straightforward swapping a 280ZX 5 speed into your car is, what prompted your decision to do the much more difficult job?

Most Likely - - -

240SX transmission

- stronger, new and improved design

- gearing 1st through 4th closer to original

- easier to find low mileage examples today

- usually not too expensive

- rebuild parts still easily available

FWIW,

Carl B.

[Arne]

Most Likely - - -

240SX transmission

- stronger, new and improved design

- gearing 1st through 4th closer to original

- easier to find low mileage examples today

- usually not too expensive

- rebuild parts still easily available

OK, I can see where these are all desirable things. However:

• stronger, new and improved design - perhaps, but I doubt that any stock or mildly enhanced 240/280Z truly needs a stronger tranny for street use.
• gearing 1st through 4th closer to original - a generally good thing, but again, I doubt the differences are all that significant for a street-driven Z.
• easier to find low mileage examples today - probably true in much of the country. Not so much here in the West, where there's still plenty of Z/ZX transmissions available.
• usually not too expensive - neither are the ZX trannies.
• rebuild parts still easily available - I had no trouble getting rebuild parts for my Type A last year, and Type B 5 speeds should be even easier to get parts for.
  

Not trying to say this is a bad idea, I don't see much downside to it, other than all the extra work and cost to pull it off.

[Walter Moore]

...

stronger, new and improved design - perhaps, but I doubt that any stock or mildly enhanced 240/280Z truly needs a stronger tranny for street use....

When I bought my 240Z (in 2002) it had been sitting in a warehouse for more than a decade. The transmission that came in it was from a 280Z, and the syncros for 2nd gear were shot. The title (from 1983) listed the purchase mileage at 134k miles and the odometer read just a little over 40k. From that I assume the car had about 140k miles, was on at least its second transmission, and that one was pretty much shot.

A stronger transmission would be a good thing...

[280~Master]

I have heard of this swap and have thought about it for the simple fact that you can get better gearing for the 240sx tranny.

[doradox]

The 240SX runs a 4:10 rear end stock. If you don't have at least a 3:90 you might be a little disappointed with the gearing. Or not. I have one (240SX) and I'm not a big fan of the rpm drop in the 1-2 shift. First is just a little too low so the jump to second is a little too much IMHO. But the rest have nice spacing. With a 3:90 the 1-2 shift would be little worse, but at least first gear wouldn't run out so quick and you'd be turning a few less rpm at highway speeds.

Steve

[Darbji280z]

Well, basically I needed a transmission solution. And after looking at different options, I decided not to go with the 280zx trans because I am certain to have the same problem with syncros going out. All of the zx transmissions I was able to find were expensive and had higher miles than my own broken transmission.

I am really excited about this swap. In fact all I am waiting for is the bell housing and driveshaft to come back from the machine shop! I will keep you posted. Thanks for all the info.

[Arne]

All sounds good. You did your research, found your stuff and are getting it handled. I hope it turns out as good as you hope.

[preith]

Hopefully I won't get dinged for this but for anyone else interested in this swap I have a FS5W71B bell housing from a 280ZX I'm looking to sell, PM me for more info.