Black Fiber Synchros on all 5 gears?

[blodi]

So, I dropped off my 5 speed trans at the local shop here for a rebuild while I do my L28 swap. I bought a rebuild kit in advance which I dropped off with the trans. I bought the trans about a year and a half ago when I swap my car from an auto to manual. 

The tech called me today and asked about the rebuild kit having brass synchros...I told him I knew these trans had 1-4 in brass and the 5th gear sychro was a fiber disc of some sort that is apparently not available anymore. He said "well all 5 sychros are that black fiber material". So we are both puzzled. 

Did the 5 speeds ever come from the factory with all 5 sychros in the black fiber? He seems to think the new brass ones won't work as they are a different size. So maybe this trans was modified? It did come with a lightweight flywheel.  

It seems like I might be SOL on getting this trans rebuilt if that is the case and I'll be looking for another 5 speed. 

 

[Zed Head]

Where did you get the "kit"?  

Not really clear if you're saying that the tech found black fiber synchros in the transmission, or if he found them in the kit.  You say he's not sure if the new brass synchros will work because they're a different size.  New from the kit or new from somewhere else.

No offense, but it's not clear what's what.  Do you know where the transmission came from?  And are you sure the tech knows black fiber from steel?

[Zed Head]

I have a disassembled ZX 5 speed in the garage for reference.  But there are also pictures around the internet.

[blodi]

Sorry. I mean that he opened the transmission and found that there are apparently black fiber synchros for all five gears in place. 

So when he opened the rebuild kit and saw the brass ones that's when he knew something was up  

I don't know the history of the trans since I bought it from a guy that was just parting it out of a car that he had never had running and was just using for parts. 

[Zed Head]

Well that's interesting.  And your tech seems to be saying that the kit synchros are a different size?  You didn't say where the kit came from.

I've never heard of fiber synchros for all five gears.  But I have heard of modified steel synchros in place of brass.  I don't see how the tech can see enough of the synchro face to determine brass or fiber.  The teeth are still metal in both cases.  Might get a second opinion from someone who knows old Datsun parts.  You don't want someone in there who doesn't know the transmissions.  Even the "kits" that are out there are incomplete and come with wrong parts.

[Zed Head]

Forgot to say also, that I've seen cases where people who seemed to know what they were doing rebuilt their transmissions with "kits" and they turned out worse than used factory parts.  There's a guy on Hybridz who went through all of the various possibilities building a racing transmission.  He ended up paying for the Nissan synchros even though they're about $50 each.  The kit synchros just weren't very good.

Here's a comment from Oliver at ZSpecialties about synchros, and one of his kits.  Be careful.  Might be best to use it as-is.  "Rebuilt' doesn't guarantee better.

http://www.datsunstore.com/syncro-ring-through-7083-p-1458.html

http://www.datsunstore.com/trans-complete-rebuild-wsyncros-speed-7783-p-1496.html

 

 

[blodi]

I'll tell him to dive in and tear it down tomorrow. Maybe that will answer more. I think he spotted the difference right away and hit pause on doing anything more.  He seems like a really knowledgable guy.  The trans was grinding 2nd like crazy so that's why I wanted to get it rebuilt to begin with. 

[blodi]

Oh and I got the rebuild kit online,possibly eBay. I'll have to look it up. 

[Chickenman]

Quote

I don't know the history of the trans since I bought it from a guy that was just parting it out of a car that he had never had running and was just using for parts. 

What is the Transmission " supposed " to be out of ( Model number ) and is there a Tag or stamping number on it. That would help greatly. You may have a Borg Warner 5 speed.

The Borg Warner 5 speeds ( T5 ) may have had fiber synchro's, as that was common on the T5's that they built for Chevy and Ford in the early 80's. But I'm not 100% sure if the Datsun BW T5's used Carbon or Fiber synchro's. Maybe someone else can chime in.

 

Edit 1: After a bit of research, it looks like early versions of the Datsun BW T5 came with brass synchros, but later versions changed to the fiber synchros. BTW, nothing wrong with the fiber synchros. Thye actually shift as well or better than the Brass ones.

Edit 2: The BW transmission has a separate bell housing, center case and tail housing. Apparently you can bolt a Ford T5 center case to the Datsun bell housing. That opens up using WC T5 trannies ( World Class ) and those do have Fiber synchros. And Taper roller bearings on the main-shaft which are a big plus. Prop[er transmission identification is going to be critical.

Can you take a picture of the tranny? There were 3 types of 5 speeds available on Z and ZX cars. The 1983+ BW-T5 was a different beast altogether. And then there are apparently S13 and S14 5 speeds that can be used in Z's and ZX's.

 

http://www.zcarz.us/TechnicalInformationPageTransmission.htm

Edited January 2, 2016 by Chickenman

[blodi]

^Interesting. Here are the only pics I have of the trans in question.....

IMG_5357 by blodi, on Flickr

IMG_5358 by blodi, on Flickr

IMG_5361 by blodi, on Flickr

 

[Zed Head]

Assuming that it came from a Z car (there's another discussion out there about all of the other possibilities), that looks like a plain-old 77-78 280Z five speed.  The passenger-side exhaust hanger, the speedo gear bolt, and the dust shield at the tail (not often mentioned but it's a sign - the ZX castings don't have it).  Not a 71C or BW, definitely, because they use a shifter mechanism that drops in through a 6 bolt plate on the top.

I still wonder about your guy.  One key to "success" in the auto repair business is to sound like you know what you're doing.  Nobody leaves their car/parts with a guy who doesn't.

[blodi]

Yeah, That's what I was sure it was. But I'm still a bit new to these cars. I'll press the guy to pull it apart further and maybe send me some pics. With New Years and the weekend he's been out of the shop.