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Zx 5 speed rebuild


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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?

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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.

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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

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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

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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

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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.

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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

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  • 3 months later...

@Patcon, I just finished rebuilding my early FS5W71B. I encountered what I think is a discrepancy in the 79/80 FSMs, in the Manual Transmission Section. I meant to take a couple of pictures before putting the case back together so that I could post here to document the issue, but forgot. I'm hoping your transmission is in a state where you might be able to take the pictures I didn't. So, here's the thing:

When installing the OD-Reverse Synchro Hub, the 1979 FSM says the following on page MT-16: Note: Assemble OD-reverse synchronizer hub, paying attention to its direction.  It refers to the following diagram, which I believe is WRONG. The arrow should point to the right (towards the front) - the protrusion on the synchro hub butts up against the mainshaft bearing and allows the splined part of the hub to clear the bearing retainer (both of which are forward of the synchro hub). If the flat (non-protruding) part of the hub is oriented forward, the whole thing just butts against the retainer plate. 

image.png

If you could take a photo or two of the hub showing the actual orientation - maybe one showing the protrusion butting against the bearing, and another with the slider all the way forward, showing the groove in the splines facing rearward, it would be helpful for other rebuilding an early FS5W71B.

 

Edited by pogden
removed duplicate image
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I could be wrong (keep in mind that I'm rebuilding my FS5W71B and keep having to undo what I put together) but I think you are missing a spacer (part 32624).

Just wondering, I think I read that you bought a rebuilding kit from Rock Auto. Does the input shaft bearing in your kit have a retaining ring because mine did not and I'm waiting on a new bearing that has the clip.

Edited by Jeff Berk
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Jeff, I believe the spacer you are referring to exists in the later (close ratio) FS5W71B that was available in ~1981. The synchro design was changed, and the three-pronged spacer (32624 - I think it’s actually called an insert retainer) was part of that and it is indeed the first thing on the mainshaft behind the mainshaft bearing - on the later model transmission.

Regarding the RockAuto kit, it does not contain any retaining rings. I assume you are referring to the "main drive bearing snap ring"? I just reused mine. I hope you can find one - it seems critical to the proper axial positioning of the input shaft relative to the mainshaft. When the mainshaft, input shaft, and counter gear assemblies are all fit together and pressed into the bearings in the adapter plate, there is some fore/aft movement possible between the mainshaft and the input shaft. When I was testing the rotation/movement of the various parts, I noticed that if I pushed the input shaft firmly back against the mainshaft, the whole thing sort of "froze", but if I allowed the input shaft assembly to float forward, everything moved freely. Once everything is reinstalled in the case and the front cover is attached, I think the big snap ring keeps the right fit between the input shaft assembly and the mainshaft assembly (which is locked into place in the adapter plate by the mainshaft nut).

Sent from my iPad using Tapatalk Pro

Edited by pogden
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Well, it's difficult to say what year my transmission is at this point. The 5th gear part is off a '82 worn out trany, most of the rest of the innards are out of a '78(?) 4 speed, and the shafts (except the input) are out of my 70 something transmission that a PO installed in the early 80's. Not sure how it's going to work once I get it together... kind of sounds like that old Johnny Cash song.

Edited by Jeff Berk
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  • 2 weeks later...
Posted (edited)

@EuroDat

Chas,

I have been unable to locate a replacement reverse idler. What steps do I need to take to make this more serviceable?

 We also started tear down yesterday. I built a gear tree out of some material we had laying around

spacer.png20210410_162709.jpg20210410_165028.jpg

Edited by Patcon
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On 3/26/2021 at 12:58 PM, pogden said:

I just finished rebuilding my early FS5W71B. I encountered what I think is a discrepancy in the 79/80 FSMs, in the Manual Transmission Section. I meant to take a couple of pictures before putting the case back together so that I could post here to document the issue, but forgot. I'm hoping your transmission is in a state where you might be able to take the pictures I didn't. So, here's the thing:

I don't think I know which gear you are referring to. Is it in any of these pictures?

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2 hours ago, Patcon said:

@EuroDat

Chas,

I have been unable to locate a replacement reverse idler. What steps do I need to take to make this more serviceable?

 We also started tear down yesterday. I built a gear tree out of some material we had laying around

An alternative could be just replace the complete reverse gear setup. The kit for the 4 cylindrr FS5W71C uses a 21T reverse idler, so you will need the slider and cluster gear. Complete for US $79.

I'm almostcertain the splines on the cluster and the inner teeth on the slider are the same on the 71B and 71C, but just to be sure, count the the inner teeth on the slider and the splines on the cluster gear. 

https://cobratransmission.com/nissan-fs5w71c-4-cylinder-reverse-gear-kit-50042095-1

The other alternative is to have the teeth ground down and de-burred/rounded, but it is a lot of work and will cost more than buying another set with a slightly different ratio.

 

Screenshot_20210411-205328.jpg

Screenshot_20210411-205413.jpg

Edited by EuroDat
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That's great! I will count them...

On a different note, is the 4 speed reverse of a similar construction that I could pirate all 3 pieces from a spare 4 speed?

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Posted (edited)
On 4/11/2021 at 2:52 PM, EuroDat said:

An alternative could be just replace the complete reverse gear setup. The kit for the 4 cylindrr FS5W71C uses a 21T reverse idler, so you will need the slider and cluster gear. Complete for US $79.

I'm almostcertain the splines on the cluster and the inner teeth on the slider are the same on the 71B and 71C, but just to be sure, count the the inner teeth on the slider and the splines on the cluster gear. 

https://cobratransmission.com/nissan-fs5w71c-4-cylinder-reverse-gear-kit-50042095-1

The other alternative is to have the teeth ground down and de-burred/rounded, but it is a lot of work and will cost more than buying another set with a slightly different ratio.

 

Screenshot_20210411-205328.jpg

Screenshot_20210411-205413.jpg

No joy!!

Small gear seems to match

Middle gear would probably work, but the slider we have has 37 external teeth versus 36 and 36 Internal teeth versus 30. It also looks like it has a different construction...

Edited by Patcon
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On 4/11/2021 at 10:22 AM, Patcon said:

I don't think I know which gear you are referring to. Is it in any of these pictures?

Yes, the one below. This is the OD-Reverse Synchronizer Slider (in hand) and Hub (circled). The photo was taken from the rear of the transmission facing forward, and the the synchronizer hub is clearly oriented with the concentric groove aft, which is opposite of the diagram in the FSM. 

 

OD-Reverse_syncho_hub.png

Patcon_FS5W71B-2.jpg

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2 hours ago, pogden said:

Yes, the one below. This is the OD-Reverse Synchronizer Slider (in hand) and Hub (circled). The photo was taken from the rear of the transmission facing forward, and the the synchronizer hub is clearly oriented with the concentric groove aft, which is opposite of the diagram in the FSM. 

 

OD-Reverse_syncho_hub.png

I corrected that in my FSM and posted it in a thread here somewhere 3 or 4 years ago. The problem I had was the original document has a password.

I could not change it or add any comments. To get around that I printed it and scanned it in. The only problem with that is you loose quality of the whole document or increase file size considerable just to fix two diagrams (this one and another on the following page).

Thinking about it, I could make it a supplement document with just  those two pages. Then you can download the two MT documents and if you decide to print them, simply replace the pages.

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6 hours ago, Patcon said:

No joy!!

Small gear seems to match

Middle gear would probably work, but the slider we have has 37 external teeth versus 36 and 36 Internal teeth versus 30. It also looks like it has a different construction...

That is unfortunate. Good you checked that before ordering the parts. I was hoping the slider would match, but that kit is for a C version and later versions seem to have "improvements" that look very much the same but not...

Can you post a couple of photos showing the chipped section of the idler gear? It's is good to check if they are just chips and not shattered. From what I remember it wasn't that bad so it should clean up ok.

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I think these are in order. Rotating clockwise

20210417_113647.jpg20210417_113649.jpg20210417_113656.jpg20210417_113701.jpg

I assume trying to MIG these back up won't work because they're hardened...

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31 minutes ago, Patcon said:

I think these are in order. Rotating clockwise

20210417_113647.jpg20210417_113649.jpg20210417_113656.jpg20210417_113701.jpg

I assume trying to MIG these back up won't work because they're hardened...

I wonder if you can TIG it with an appropriate feed rod. Might have to manage the heat as well, don’t let it cool off too fast. 

Shaping them after will be interesting, might be able to file it down slowly.

Hopefully we can see some lights on that Christmas gear tree you have.. maybe during the holiday season 😛 

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Posted (edited)
8 hours ago, heyitsrama said:

I wonder if you can TIG it with an appropriate feed rod. Might have to manage the heat as well, don’t let it cool off too fast. 

Shaping them after will be interesting, might be able to file it down slowly.

Hopefully we can see some lights on that Christmas gear tree you have.. maybe during the holiday season 😛 

I hope that tree is empty by Christmas!! Lol

We do have a TIG rig. I could go ask our welding rep

Edited by Patcon
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