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

transmission replacement question

Thread Tools
 
Search this Thread
 
Old Jul 27, 2017 | 09:43 AM
  #1  
Geodim's Avatar
Geodim
Thread Starter
Heel & Toe
 
Joined: Oct 2016
Posts: 20
Likes: 0
From: Vernon CT
Default transmission replacement question

I just popped the transmission in my 1988 Corvette. I have an opportunity to pick up a 700r4 from a firebird. Will this transmission fit my car? I need to get this back on the road asap.

Thanks in advance!!
Reply
Old Jul 27, 2017 | 11:25 AM
  #2  
knikula's Avatar
knikula
Instructor
 
Joined: Jun 2015
Posts: 128
Likes: 13
Default

IIRC, the output shaft of the firebird (assuming here the firebird has a v8 700r4) needs to be cut shorter about 5/8".... and then swap the talihousing. there are threads here that detail this... You'll need to search for them.

Good luck
Reply
Old Jul 27, 2017 | 12:16 PM
  #3  
Geodim's Avatar
Geodim
Thread Starter
Heel & Toe
 
Joined: Oct 2016
Posts: 20
Likes: 0
From: Vernon CT
Default

Originally Posted by knikula
IIRC, the output shaft of the firebird (assuming here the firebird has a v8 700r4) needs to be cut shorter about 5/8".... and then swap the talihousing. there are threads here that detail this... You'll need to search for them.

Good luck
Can I just use the output shaft from the popped transmission? is that more work that I need to do?
Reply
Old Jul 27, 2017 | 12:49 PM
  #4  
confab's Avatar
confab
Melting Slicks
 
Joined: Nov 2013
Posts: 3,451
Likes: 336
From: Greater Cincinnati Area.
Default

Originally Posted by Geodim
Can I just use the output shaft from the popped transmission? is that more work that I need to do?
You can, but it will require partial disassembly.

Not hard, but you need to be sure to get the input drum seated properly or it will cause damage. The trans will need to be standing up, with the pump pointed at the ceiling. You will need a pump gasket at a minimum.

Last edited by confab; Jul 27, 2017 at 12:50 PM.
Reply
Old Jul 27, 2017 | 02:27 PM
  #5  
383vett's Avatar
383vett
Race Director
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Default

Originally Posted by Geodim
Can I just use the output shaft from the popped transmission? is that more work that I need to do?
It'll be a lot easier to cut the end off of the Firebird tranny. I used a cutoff wheel when I did it. Cover the rest of the tailshaft with a rag so particles don't get into the tranny and use a shopvac when you're cutting.
Reply
Old Jul 27, 2017 | 03:06 PM
  #6  
Geodim's Avatar
Geodim
Thread Starter
Heel & Toe
 
Joined: Oct 2016
Posts: 20
Likes: 0
From: Vernon CT
Default

Originally Posted by knikula
IIRC, the output shaft of the firebird (assuming here the firebird has a v8 700r4) needs to be cut shorter about 5/8".... and then swap the talihousing. there are threads here that detail this... You'll need to search for them.

Good luck
Sorry not lazy, just generic searches give me hundreds upon hundreds of results to go through.. what should I search on to find the articles / posts you mentioned? Want to see what it entails before I buy a transmission I found..

Regards,
G
Reply
Old Jul 27, 2017 | 03:27 PM
  #7  
confab's Avatar
confab
Melting Slicks
 
Joined: Nov 2013
Posts: 3,451
Likes: 336
From: Greater Cincinnati Area.
Default

https://www.corvetteforum.com/forums...difficult.html
Reply
Old Jul 27, 2017 | 03:41 PM
  #8  
knikula's Avatar
knikula
Instructor
 
Joined: Jun 2015
Posts: 128
Likes: 13
Default

Originally Posted by Geodim
Sorry not lazy, just generic searches give me hundreds upon hundreds of results to go through.. what should I search on to find the articles / posts you mentioned? Want to see what it entails before I buy a transmission I found..

Regards,
G
It was trial and error for me on that search too, I have no recollection of what terms finally made me stumble onto it....

I freely admit to being quite lazy... and I see confab came thru for you already...

If you take the output shaft from the old tranny, you'll learn a whole lot more about the tranny.... but I'd cut the firebird shaft in a heart beat ...

You'll get a chance to see the guts soon enough....
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 Jul 27, 2017 | 03:49 PM
  #9  
Geodim's Avatar
Geodim
Thread Starter
Heel & Toe
 
Joined: Oct 2016
Posts: 20
Likes: 0
From: Vernon CT
Default

Originally Posted by knikula
It was trial and error for me on that search too, I have no recollection of what terms finally made me stumble onto it....

I freely admit to being quite lazy... and I see confab came thru for you already...

If you take the output shaft from the old tranny, you'll learn a whole lot more about the tranny.... but I'd cut the firebird shaft in a heart beat ...

You'll get a chance to see the guts soon enough....
So literally.. from what I read... cut the shaft with a cut off wheel. swap the tail shaft housing... then swap the speedo gears? Does that sound too simple? believe me, I can screw up a wet dream....
Reply
Old Jul 27, 2017 | 04:00 PM
  #10  
confab's Avatar
confab
Melting Slicks
 
Joined: Nov 2013
Posts: 3,451
Likes: 336
From: Greater Cincinnati Area.
Default

Originally Posted by Geodim
So literally.. from what I read... cut the shaft with a cut off wheel. swap the tail shaft housing... then swap the speedo gears? Does that sound too simple? believe me, I can screw up a wet dream....
Yeah, basically. If you are cutting:

Remove the tailshaft housing from both.

Measure from the rear of the case on the vette unit and cut the shaft on the firebird unit to the same length. Deburr and chamfer the cut and use a triangle file or something similar to clean up the splines.

Reassemble with vette tailshaft housing and spedo gears.

It would be REALLY HARD to screw this up.. It's like 5 bolts.

Last edited by confab; Jul 27, 2017 at 04:02 PM.
Reply
Old Jul 27, 2017 | 05:14 PM
  #11  
383vett's Avatar
383vett
Race Director
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Default

Originally Posted by confab

It would be REALLY HARD to screw this up.. It's like 5 bolts.
Actually harder. An 88 has only 4 bolts.
Reply
Old Jul 27, 2017 | 05:15 PM
  #12  
confab's Avatar
confab
Melting Slicks
 
Joined: Nov 2013
Posts: 3,451
Likes: 336
From: Greater Cincinnati Area.
Default

Originally Posted by 383vett
Actually harder. An 88 has only 4 bolts.
spedo gear..


Reply
Old Jul 27, 2017 | 06:58 PM
  #13  
383vett's Avatar
383vett
Race Director
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Default

Originally Posted by confab
spedo gear..


Ouch!
Reply
Old Jul 28, 2017 | 12:58 AM
  #14  
Geodim's Avatar
Geodim
Thread Starter
Heel & Toe
 
Joined: Oct 2016
Posts: 20
Likes: 0
From: Vernon CT
Default

ok, so curious.. anyone in Connecticut (or nearby) by chance have a good 700R4 that will go into my 1988 that they are willing to sell to a guy on a budget?
Reply

Get notified of new replies

To transmission replacement question





All times are GMT -4. The time now is 10:21 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