C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Black tag?

Thread Tools
 
Search this Thread
 
Old Jun 25, 2014 | 10:44 PM
  #1  
smooth1990's Avatar
smooth1990
Thread Starter
Drifting
 
Joined: Feb 2013
Posts: 1,465
Likes: 12
Default Black tag?

So I pulled the trans today. Its been rebuilt obviously. Is this what everyone considers a "Black Tag"?


Reply
Old Jun 25, 2014 | 11:51 PM
  #2  
black_89_vette's Avatar
black_89_vette
Melting Slicks
25 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Nov 2000
Posts: 2,469
Likes: 6
From: Winchester Ontario
Default

Originally Posted by smooth1990
So I pulled the trans today. Its been rebuilt obviously. Is this what everyone considers a "Black Tag"?


Yes, that's a black tag.
Reply
Old Jun 26, 2014 | 02:12 AM
  #3  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,394
Likes: 2,741
Default

The 044 build is '92 & '93 and is the last of the 610Nm. There are later "black tag" transmissions BUT they're NOT 610 Nm units. There's considerable misunderstandings regarding ZF identification.
Reply
Old Jun 26, 2014 | 08:30 AM
  #4  
lt4obsesses's Avatar
lt4obsesses
Le Mans Master
15 Year Member
 
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
Default

Originally Posted by WVZR-1
The 044 build is '92 & '93 and is the last of the 610Nm. There are later "black tag" transmissions BUT they're NOT 610 Nm units. There's considerable misunderstandings regarding ZF identification.
As I understand it...The ZF6 came pre-assembled, pre-filled from ZF in Germany. It was a non-serviceable part. So when a customer brought the car in with a trans issue, they send the old one back to ZF and install a new one. ZF in turn would reman the trans and those became replacements. If this was done after '93, the reman'd trans was built with the 'blue tag' gears, which were quieter. Those trans would have the original black tag, as well as a blue tag added to it. (manufacturer tag, not the one in the pic)

Transmission noise was a relatively common complaint with the black tags, depite the use of the DMF, and people would bring them in, and they got replaced. Being a non-serviceable part, they couldn't take apart to see if it was actually faulty. So they just pulled it and replaced it.

At least, this is how I understand the story about the ZF in the C4.
Reply
Old Jun 26, 2014 | 11:34 AM
  #5  
smooth1990's Avatar
smooth1990
Thread Starter
Drifting
 
Joined: Feb 2013
Posts: 1,465
Likes: 12
Default

Originally Posted by WVZR-1
The 044 build is '92 & '93 and is the last of the 610Nm. There are later "black tag" transmissions BUT they're NOT 610 Nm units. There's considerable misunderstandings regarding ZF identification.
Isn't the input and output shafts bigger on the black tag transmission?
Reply
Old Jun 26, 2014 | 12:19 PM
  #6  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,394
Likes: 2,741
Default

Originally Posted by smooth1990
Isn't the input and output shafts bigger on the black tag transmission?
No - neither.
Reply
Old Jun 26, 2014 | 12:31 PM
  #7  
smooth1990's Avatar
smooth1990
Thread Starter
Drifting
 
Joined: Feb 2013
Posts: 1,465
Likes: 12
Default

Originally Posted by WVZR-1
No - neither.
Hmm that's what I thought was the difference. What exactly is different between the two then?
Reply
Old Jun 26, 2014 | 01:59 PM
  #8  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,394
Likes: 2,741
Default

Originally Posted by smooth1990
Hmm that's what I thought was the difference. What exactly is different between the two then?
There are only two input shafts for the ZF. An LT1/4 - L98 length and an LT5 length. All 610 Nm and 540 Nm are the same.


Originally Posted by smooth1990
Isn't the input and output shafts bigger on the black tag transmission?
You asked bigger and they're not and that's what I answered. The pitch of the internals are different on both the counter shaft gears and the main-shaft gears which resulted in the "less noise" and also the diminished power handling capabilities. The main-shaft is "different" but NOT bigger.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old Jun 26, 2014 | 05:28 PM
  #9  
smooth1990's Avatar
smooth1990
Thread Starter
Drifting
 
Joined: Feb 2013
Posts: 1,465
Likes: 12
Default

Originally Posted by WVZR-1
There are only two input shafts for the ZF. An LT1/4 - L98 length and an LT5 length. All 610 Nm and 540 Nm are the same.




You asked bigger and they're not and that's what I answered. The pitch of the internals are different on both the counter shaft gears and the main-shaft gears which resulted in the "less noise" and also the diminished power handling capabilities. The main-shaft is "different" but NOT bigger.
Thanks for clearing that up! I wasnt sure!

Any idea how much power the black tag 610 Nm can handle?
Reply
Old Jun 26, 2014 | 05:47 PM
  #10  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,394
Likes: 2,741
Default

Originally Posted by smooth1990
Thanks for clearing that up! I wasnt sure!

Any idea how much power the black tag 610 Nm can handle?
I don't recall ever seeing a # posted that actually "broke" a ZF. Have ZF's failed? Certainly but then one needs to know the why. Could be poor maintenance or any number of reasons. I'd think most were maybe abuse (being beat on), not used hard but "abused".

One needs to understand 6th wasn't intentioned to be an everyday "high speed" gear. One goes crazy with rear axle ratio and starts asking for more from 6th and it just wasn't intentioned for that use.
Reply
Old Jun 27, 2014 | 12:28 AM
  #11  
lt4obsesses's Avatar
lt4obsesses
Le Mans Master
15 Year Member
 
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
Default

Originally Posted by smooth1990
Isn't the input and output shafts bigger on the black tag transmission?
Not sure if it was wider (diameter) or just cut differently, but the black tag and blue tag require different throw out bearings.
Reply
Old Jun 27, 2014 | 01:18 AM
  #12  
WVZR-1's Avatar
WVZR-1
Team Owner
20 Year Member
Veteran: Army
Active Streak: 30 Days
Liked
 
Joined: Sep 2003
Posts: 25,394
Likes: 2,741
Default

Originally Posted by lt4obsesses
Not sure if it was wider (diameter) or just cut differently, but the black tag and blue tag require different throw out bearings.
That's not a difference dictated by the input shaft but the guide tube that is used in the build, guide tubes are different diameters. There's two lengths, LT1/4-L98 with both diameters and LT5 in both diameters. Swapping the guide tube and retainer ring can change the release bearing required for the install.
Reply

Get notified of new replies

To Black tag?





All times are GMT -4. The time now is 03:22 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE