Jump to content
Patcon

Zx 5 speed rebuild

Recommended Posts

45 minutes ago, EuroDat said:

Btw, That punch mark is the original nissan production method. The one that now holds the nut from turning is aftermarket rebuild.

That's what I suspected.

No concern about damaging threads if I don't deal with the rebuild punch marks and try to turn it off?

Share this post


Link to post
Share on other sites

9 hours ago, Patcon said:

That's what I suspected.

No concern about damaging threads if I don't deal with the rebuild punch marks and try to turn it off?

If you don't have something suitable, I would buy an el-cheapo screwdriver and grind it down to the same width as the groove and make the point more chissel like. With that you should be able to lift up the tab on the nut just enough so it won't tear when you unscrew it.

They rearly damage the threads, but when the nut is hammered in like yours, you can tear that section out of the nut when you unscrew it. That is all you are trying to avoid with the screwdriver.

Share this post


Link to post
Share on other sites
7 hours ago, EuroDat said:

If you don't have something suitable, I would buy an el-cheapo screwdriver and grind it down to the same width as the groove and make the point more chissel like. With that you should be able to lift up the tab on the nut just enough so it won't tear when you unscrew it.

They rearly damage the threads, but when the nut is hammered in like yours, you can tear that section out of the nut when you unscrew it. That is all you are trying to avoid with the screwdriver.

Sorry Chas,

I was referring to the round punch mark in the nut. It seems pretty deep

Share this post


Link to post
Share on other sites

55 minutes ago, Patcon said:

Sorry Chas,

I was referring to the round punch mark in the nut. It seems pretty deep

Looking at the photo more closely, it looks like the bottom of the punch mark is protuding into the shaft. I can't remember every seeing a indent other than the notch.

If there is a indent you would expect it to be exactly 180 degrees to the notch. Otherwise it would be difficult to locate where to punch it. The indent is not noticable outside the nut.

I don't think it will be a problem. It's probably sheared off when it was removed the first time round.

Screenshot_20201220-180242.jpg

Share this post


Link to post
Share on other sites

I thought this was probably an add on from a previous rebuild to prevent the nut from unwinding.

Also, it appears from some late night ratio calculating and a Zcars technical page that this is a 1980 transmission. I have a rebuild kit that says 80-83. Are all the parts going to work? What parts do I need to verify?

http://www.zhome.com/ZCMnL/tech/GearRatios.html

1st 3.062

2nd 1.858 

3rd 1.308

4th 1.000

5th 0.773

Share this post


Link to post
Share on other sites
1 hour ago, Patcon said:

I thought this was probably an add on from a previous rebuild to prevent the nut from unwinding.

Also, it appears from some late night ratio calculating and a Zcars technical page that this is a 1980 transmission. I have a rebuild kit that says 80-83. Are all the parts going to work? What parts do I need to verify?

http://www.zhome.com/ZCMnL/tech/GearRatios.html

1st 3.062

2nd 1.858 

3rd 1.308

4th 1.000

5th 0.773

They are the ratios for the 79 to 6-80 280ZX coupe early close ratio 5 speed. Strange thing is the photos in your first post show the tell tale signs of a wide ratio. I was under the belief that the early close ratio boxes had the brass synchro.

This project could shed a lot of light on this fairly rare transmission.

  • Like 1

Share this post


Link to post
Share on other sites

I didn't check them all because that seemed moot. But the 5th gear and 1st gear were spot on those ratios.

We may start breaking it down next week

  • Like 1

Share this post


Link to post
Share on other sites

Cody made a puller today. The OTC bearing splitter has 5/8-18 threaded holes. I went by our local fastener supply and got a section of hardened rod and some nuts and washer and a piece of flat stock from Depot. It will pull to 20"s depth...

We used a center arbor from another puller that was 5/8-18 too.

20201222_204913.jpg20201222_204918.jpg20201222_204921.jpg20201222_204923.jpg

  • Like 3

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.