280Z 5 speed, How bad is it?

[Neal G]

I did my research and decided on the 81/83 zx 5 speed and a later switch to a 3.9 or 4.11 diff.... Saved my money and ordered a rebuilt from a reputable z shop that does tranny rebuilds. There was some confusion evidently because they sent me a 77/79 z 5 speed. Not the ratio I wanted, I'm very disapointed because now they tell me they don't have one within the years I want and I have this fresh 77/79 sitting on my front porch. They have offered a refund if I want but I thought I would get some input from others that have run this tranny, before I go to the trouble of shipping it back. How bad is it? Is second gear right on top of first like the #'s show and how bad is the jump from second to third? Also, are there any advantages to the shorter 5th gear? I would appreciate any input I can get, includiny any recomendations on rear gearing.

Thanks, neal

[Poindexter]

I have the close-ratio. I'd much rather have a longer first gear, and a wider spread on the rest of the gears, based on my typical usage pattern- which of course might vary from yours. Having never driven this other trans, I unfortunately can't compare based on my actual experience- something I really want to do for my own knowledge. But as much as I love my Z, I do wish I had different gearing, FWIW. As well as adding an LSD too.

FYI I turn 3,500rpm at 80mph in 5th on the flats, which is not bad at all. Allegedly, ahem.

I'll do this when the rebuild time comes- hopefully in many, many years!

[Darrel]

I definitely prefer the late 5 spd. The big difference is 2nd to 3rd. While on the track I could redline the tach in 2nd and when I shifted to 3rd there was a big drop in rpm almost to the point of chugging. I went from a 4 spd to the late 5 spd.

It depends how much spirited driving you are going to do.

[DeMoore]

I would keep the engine and find a 77 or 78 rolling shell to put it into. =)

[240ZMan]

Like Darrel said, the gap from 2nd to 3rd is too big in my opinion with the early 5 speeds. (The first 4 gears are the same as the 4 speed if that gives you a point of reference.) I'm sure you're hoping to hear that it's a reasonable compromise, but I'd send it back and wait until I could find what I wanted. BTW, a late 5 speed with 4.11 diff is a sweet combination. I couldn't be happier with that combination both on the street and on the track.

[Rockr69]

I second 240ZMan, the later 5 speed is sweet! Wish I could get a 4.11 diff, someday!

[240ZMan]

Wish I could get a 4.11 diff, someday!

FWIW, I found mine in as the front diff of a nissan 720 (pickup) 4x4.

[sblake01]

Like Darrel said, the gap from 2nd to 3rd is too big in my opinion with the early 5 speeds. (The first 4 gears are the same as the 4 speed if that gives you a point of reference.)

Not true. Been argued before here and on other sites and I won't argue it any further here but the first four gears are not the same on a 77-78 5spd and the early 4 speed. I'll just say, look it up.

[m4xwellmurd3r]

sblake I don't think he ment the early 5 speed have the same ratio as the early early 4speed (which they aren't) but the "early" 5 speeds (that is, the 77-78 version) has the same first 4 as the same year 4 speed, and to use that as a reference if say, he had a late model 4 speed laying around.

[240ZMan]

I should have been more clear. If you normalize the ratios using 3rd as a baseline, then you see that for the 4 speed 1st is 2.50 times 3rd, and 2nd is 1.55 times 3rd. For the early 5 speed, 1st is 2.54 times 3rd and 2nd is 1.59 times 3rd. In other words, on a relative basis, 1st, 2nd and 3rd gears are all the same (within a small tolerance) for those two transmissions.

If you were to swap the early 5 speed and leave the 3.36 diff, then 1st, 2nd, and 3rd would all provide slower acceleration than with the 4 speed. If you were to swap the diff to 3.54 at the same time, then 1st - 3rd would be almost the same as before. You would still have a relatively large change in ratio going from 2nd to 3rd. The later 5 speed has 3rd gear closer to 2nd which was the point Darrel and I were originally making.

Perhaps these 2 screen shots from the transmission calculator will make it more clear. Note that the max speed in the first 3 gears is nearly the same for both combinations.

[sblake01]

sblake I don't think he ment the early 5 speed have the same ratio as the early early 4speed (which they aren't) but the "early" 5 speeds (that is, the 77-78 version) has the same first 4 as the same year 4 speed, and to use that as a reference if say, he had a late model 4 speed laying around.

I was comparing the type B 4 speed to the 77-79 5 speed strictly by gear ratio. Not the type A 3 piece 'monkey motion' early 4 speed. My point stands, the gear ratios in the trans are not the same. I won't bother posting the chart. It's already on the site somewhere. If you want to go on thinking they're the same that's up to you. It's really a rather moot point anyway.

[m4xwellmurd3r]

well, from what i saw on zhome, the 77-79 4 speed and 5 speed share the same gear ratios.....