I am debating on this: my current 4 speed trany is healthy,tight no issues,recent clutch and bearings this is the way it came to me on the Z purchase. I came across and secure a 5 speed trany, did my research on it on and it is the proper one for the swap.My question to you guys ....I don't want to open a can of worms ,encounter problems,go money crazy on this. Your input will be very valuable to me. My Z is a 72.

IMy question to you guys ....I don't want to open a can of worms ,encounter problems,go money crazy on this. Your input will be very valuable to me. My Z is a 72.

Sorry, what's your question?

Dennis

Is this swap an avenue for: opening a can of worms,encountering needless problems, a financial mistake.

Edited February 22, 201213 yr by 72 OJ

Is this swap an avenue for: opening a can of worms,encountering needless problems, a financial mistake.

Probably not. But anything is possible.

Dennis

The 77 to 79 5 speeds have the same 1 - 4 ratios as the 4 speeds. If you don't find your self wishing that you had one more gear to shift up to while on the highways, then, yes, it would probably be everything that you're worried about. A lot of risk with very little benefit.

If you're looking for different ratios, and have one of the ZX type 5 speeds with the closer 1 - 4 gear sets, then the risk/benefit ratio changes. But unless you open the transmission and look you won't know what you're installing, so you could get a noisy, poor-shifting old transmission (of course, they're all old). Otherwise, it's a pretty direct, bolt-in swap for both types of 5 speeds..

The swap is much easier on a '72 than an "70 or early '71. It is basically a direct bolt in swap. Which year 5 spd are you looking at?

I would recommend that you get the matching diff for the 5 spd though to get the maximum benefit out of it. Your '72 came with a 3.36 R180 (unless it is an automatic, then probabaly a 3.54). The 5 spds were usually mated to a 3.90 R200 diff. If you go with the R200, you will need a 280Z moustashe bar. It is a little more effort, but worth it. Do a search on 5sd swaps, as it has been written up a lot. While you have the diff out, put in a R/T mount. Do a search for info on that.

Like the guys said above, your risk is buying an unknown condition used tranny.

In the end it's a great swap.

Marty

Yes, what 5 speed? The T-5 that came in the turbos will come with extra work since it has a dedicated driveshaft. The better swap is as stated above.

Marty brings up a good point. I missed the fact that the 240Z four speeds actually have a different set of gear ratios, with a much lower 1st gear,, than the 75-79 four speeds. Negating most of what I said. It looks like some work involved to get that extra gear.

Let's see if my Excel numbers will be legible if I paste them in here. Nope, no WYSIWYG. Move the bottom 5th gear numbers over one column and it works. -

72-74 75-79 80 81-83

3.592 3.321 3.062 3.062

2.246 2.077 1.858 1.858

1.415 1.308 1.308 1.308

1 1 1 1

0.864 0.773 0.745

Edited February 22, 201213 yr by Zed Head

I think as long as you go with an early close ratio 5 speed you will not be disappointed it should be a straight swap and would give you the same performance with a better cruising gear for the highway. If you are wanting strictly gas mileage you can swap the zx 5 speed but you will lose performance unless you swap to a 3.90 or higher rear end

If you use a zx 5 speed and stay with an R180 diff (3.7,3.9 or 4.11) it will be a simple swap. Just make sure you keep the clutch fork, pressure plate and throwout bearing collar as a unit. You will also need to swap out the speedo drive gear, but that will not effect performance.

Thanks for the response..........The 5 spd trany that I have came from a pull out running 78 620, miles who knows, the rear on the Z is an automatic unit from a 72.

Edited February 23, 201213 yr by 72 OJ

I will not go with this swap,,,,do not see any great benefits in messing with my Z, as stated before it's 4 speed set up is very healthy, so a have a 6 speed car ,a 5 speed and a 4 speed ,one of each.

Edited February 24, 201213 yr by 72 OJ