75 280Z - 5 speed swap from 81 280ZX - any catches I should be aware of?

[HusseinHolland]

8 hours ago, Zed Head said:

I understand how it went together.  I was asking for any future searchers wondering if this will give good results or not.  Can't tell.  If there's too much play you'll probably get vibration.  If it's off-center, the same.  It's a good quick "get by for a while" repair though.  Might be fine for a long time.  It's just much less precise than the Nissan procedure described in the FSM.

The thing is, all that is referencing the OEM u joint on models that allowed for replacement, no? It is not relevant to an aftermarket u joint that uses the yoke flat measurement & cup size to determine appropriate fit. I would have to say it is more than get by for a while. The u-joint felt perfect. It's not difficult to tell if there is end float in any of the cups. Or if the joint is binding.

[HusseinHolland]

Just to wrap this up - car is much more enjoyable with a transmission that is not screaming or whining at me the whole time, never mind the fact that the gear spacing is much better than the old 4 speed. 

70 mph in 5th is 3K rpm, was 4K with the 4 speed. And its quiet.

Installed at (2)55700K miles

I was up early today, so I trimmed my azalea bush before the sun got strong. The canna is starting to flower. I was hoping it would grow taller this year, with all the rain we've had

Edited July 20 by HusseinHolland

[HusseinHolland]

On 5/13/2024 at 9:17 AM, Dave WM said:

Oh and I forgot, does the transmission come with the shifter? if not you may need to look into what it takes to make sure the 4 speed will properly engage esp 5th gear IIRC. there is something about it not allowing the 5th detent to fully engage. easy fix with some minor grinding on the bottom of the shifter. Its well covered in this forum. 

So, after driving the Z on & off this past week, I found that it would pop out of reverse. Earlier today there was no access to ClassicZ, so I did a google search on the topic & found a topic on Zcar, that linked your video on the topic. With that info it was clear that my shifter was not dropping back far enough to engage the reverse detent & have that little shifter play once properly engaged. 2nd & 4th engaged fine, however there was really no play in the shifter that would indicate full engagement even though it hadn't popped out of the forward gears.

Final relief on the backside that allowed proper engagement. I removed small amounts & rechecked for engagement. Kept going until no marking was evident on the shifter. I also noted a nick on the front side of the rod, so I relieved that side ever so slightly.

frontside relief 

 

 

 

Edited July 26 by HusseinHolland

[Zed Head]

That's odd.  I've not heard or read of anybody having a reverse problem due to the shifter.

[Dave WM]

what is the final gear ratio? I have a 3.54 on the differential and get 80mph at 3k

[cgsheen1]

I have a close ratio ZX 5-speed and 3.54 R200 and get the same as Dave - ~80mph at 3K. But I don't have anywhere near the humidity!

Edited July 26 by cgsheen1

[HusseinHolland]

2 hours ago, Dave WM said:

what is the final gear ratio? I have a 3.54 on the differential and get 80mph at 3k

Pretty sure the 75 is 3.90 FD

[HusseinHolland]

7 hours ago, Zed Head said:

That's odd.  I've not heard or read of anybody having a reverse problem due to the shifter.

Sample search I found when ClassicZ was down  - this problem arises when using the 280Z 4 Spd shifter in the 5 Spd.

Edited July 26 by HusseinHolland

[Zed Head]

Thanks.  I found the one reference to reverse.  Doesn't look like the guy actually had the pop-out-of-gear problem though.

Yours is the first I've seen describing reverse.  If your fix fixed it, great.  Your post was a surprise.  Carry on.

 

[Dave WM]

13 hours ago, HusseinHolland said:

Pretty sure the 75 is 3.90 FD

sounds like a good combo, the issue with the 3.54 is it can limit use of high gear, but here in flat land country its generally not a problem. I do get very good gas mileage, recent trip was around 27 mpg. mostly 65ish flat highway. With the 3.54 you really can not use OD until about 60 min and then only on flats. I have a 3.7 I may try someday...

Edited July 27 by Dave WM

[Zed Head]

All of the 280Z's came with a 3.54 R200.  Swapping to a 3.9 will give better pickup in 1st and more time in overdrive.

Edited July 27 by Zed Head
fixing an error

[HusseinHolland]

9 minutes ago, Zed Head said:

All of the 280Z's came with a 3.54 R200.  Swapping to a 3.9 will give better pickup in 1st and more time in overdrive.

 

Interesting, thank you for that.

That does make it odd that my speed in gear differs from Dave - I'm using the drive gear from the 81 zx 5spd (stock drive gear was quite inaccurate with the 205/50x15's) and checking against GPS it seemed pretty accurate. I will have to reconfirm next time I'm on the highway.