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Manual To Automatic Transmission Swap

Hi, Guys! I have a 1989 Nissan 240 SX with a 1992 KA24E motor in it. I want to swap the manual transmission for an automatic. Can this be done? If so, how?

Bottom line, I don’t know if it is a practical or economically feasible thing to try or not. It can probably be done though. First step is to make sure you can resolve the fitment issues, adapters for the transmission/engine connection, then you’ll need a plan for the transmission fluid cooling, supplying the proper connections (such as a vacuum modulator, throttle valve- transmission linkage), electrical connections (for any solenoid shift valves, neutral safety switch, etc), and the vehicle speed sensor and speedometer. Hopefully there’s no computer issues, but don’t assume that. Check first.

One other thing to check is whether the crankshaft balance is going to be a problem. You’ll be switching to a flex-plate presumably, and that might require some add’l change elsewhere, like in the harmonic balancer, to maintain proper crankshaft balance.

It should be an interesting project. Me, I’d rather swap in the other direction, from automatic to manual. What’s your motivation to swap from manual to automatic beyond just seeing if it can be done?


George if was me I would for sure be going the other way.

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In a vacuum with unlimited funds, anything is possible. Realistically, I would say no, especially in 28 year old car…

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I have multiple 240sx’s and want to do something different with this one as my other two are manuals

Just curious about your cars, my buddy back in the early 70’s had a Datsun 240Z and he and I really enjoyed riding to the ski resort in that car. It was very very good on mountain roads. Not so great on really icy roads though. I thought the number in the name had changed by the late 70’s to 260Z or 280Z or something like that. So they still had 240’s as late at 1989? Just not 240 Z?

240 SX was an entirely different car, front drive, I think.

This is one of those if you have to ask maybe you should not do it. You will need a transmission. maybe bell housing, linkage, possible cooling lines and end up with something not really like you want. I would see if I could find a SX auto and make a trade. You might like these but they are not exactly collectable.

Rear wheel, im probably gonna put an ls1 in it from my 98 trans am

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Yeah 1989 240sx is the s13 first generation

I helped a buddy/former coworker of mine do that with a 91 240SX. He wanted to do a SR20 swap, but the LS1 was far easier and cheaper to obtain. He order a kit with the necessary adapters/mounts, It was as hard as either one of thought it would be, we were able to do at a somewhat leisurely pace over the course of two weekends with the help of another guy who had apparently done it before. The results were staggering, the car was very quick. Unfortunately, the rear differential grenaded in two weeks.

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Actually among the drifting set, the 240SX is highly sought after. Finding ones that haven’t been wrecked and/or heavily modified already is getting pretty difficult these days.

You’re thinking of a 240Z

OP has a 240SX . . . it’s a rear wheel drive, with a 4 cylinder. In my opinion a lot less sporty, versus a Z or ZX. Not even the same platform as the Z

In stock form, they’re not very exciting to drive. I think some of them even had plain jane stamped steel rims.

If you’ve got a lot of money to throw at it, things could change . . .

It can be done, at great expense and annoyance. And you will drop the value of the car because 1) modded and 2) modded to a slushbox!?

I’d certainly not do it until I put the LS1 in there, because you’re just gonna have to do it all over again when you do, otherwise.

A sporty car like a 240SX should be driven with a manual transmission. Maybe you should trade this one for a 1989 Nissan Maxima with an automatic transmission.

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