CorvetteForum - Chevrolet Corvette Forum Discussion

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

C4 Transmission issue

Thread Tools
 
Search this Thread
 
Old Jan 5, 2024 | 12:26 PM
Share
  #1  
robr'85's Avatar
robr'85
Thread Starter
5th Gear
 
Joined: Jan 2024
Posts: 5
Likes: 0
Default C4 Transmission issue
I have the manual 4+3 transmission in my 1985. Until the engine temp reaches 144 degrees, there is a grinding noise. What is the cause of this and how can it be repaired
Reply
0
Old Jan 5, 2024 | 12:55 PM
Share
  #2  
2011KLR's Avatar
2011KLR
Drifting
Veteran: Air Force
Photogenic
 
Joined: Sep 2022
Posts: 1,438
Likes: 378
From: Liberty, SC
2023 C4 of the Year Finalist - Unmodified
Default
Id say the main bearing in the OD is dying.
Reply
0
Old Jan 5, 2024 | 12:59 PM
Share
  #3  
2011KLR's Avatar
2011KLR
Drifting
Veteran: Air Force
Photogenic
 
Joined: Sep 2022
Posts: 1,438
Likes: 378
From: Liberty, SC
2023 C4 of the Year Finalist - Unmodified
Default
Wait... that guess was on the assumption that your sound is coming from underneath in the tramsmission area. You didnt specify, so i take back my guess until you do.
Reply
0
Old Jan 5, 2024 | 01:51 PM
Share
  #4  
robr'85's Avatar
robr'85
Thread Starter
5th Gear
 
Joined: Jan 2024
Posts: 5
Likes: 0
Default
Originally Posted by 2011KLR
Wait... that guess was on the assumption that your sound is coming from underneath in the tramsmission area. You didnt specify, so i take back my guess until you do.
Definitely coming from tranny
Reply
0
Old Jan 5, 2024 | 02:11 PM
Share
  #5  
robr'85's Avatar
robr'85
Thread Starter
5th Gear
 
Joined: Jan 2024
Posts: 5
Likes: 0
Default
Also, why would the noise disappear when engine temp hits 144 degrees? Thanks for the reply.
Reply
0
Old Jan 5, 2024 | 02:13 PM
Share
  #6  
2011KLR's Avatar
2011KLR
Drifting
Veteran: Air Force
Photogenic
 
Joined: Sep 2022
Posts: 1,438
Likes: 378
From: Liberty, SC
2023 C4 of the Year Finalist - Unmodified
Default
Does it also coincide with the OD kicking in? There is a temperature where the ECM allows OD to engage. Mine is around 133 indicated.
Reply
0
Old Jan 5, 2024 | 02:39 PM
Share
  #7  
robr'85's Avatar
robr'85
Thread Starter
5th Gear
 
Joined: Jan 2024
Posts: 5
Likes: 0
Default
Originally Posted by 2011KLR
Does it also coincide with the OD kicking in? There is a temperature where the ECM allows OD to engage. Mine is around 133 indicated.
It seems to coinside with the OD kicking in because i can feel it kick in. Always happens at 140 degrees.
Reply
0
Old Jan 5, 2024 | 02:50 PM
Share
  #8  
2011KLR's Avatar
2011KLR
Drifting
Veteran: Air Force
Photogenic
 
Joined: Sep 2022
Posts: 1,438
Likes: 378
From: Liberty, SC
2023 C4 of the Year Finalist - Unmodified
Default
Watch this....

Right at 9 minute mark, he says what is most likely happening. Stop driving the car right away.

sre
Reply
0
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

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

 Joe Kucinski
story-1

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

 Verdad Gallardo
story-2

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-3

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-4

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-5

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-6

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-7

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-8

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
story-9

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
Old Jan 5, 2024 | 03:07 PM
Share
  #9  
robr'85's Avatar
robr'85
Thread Starter
5th Gear
 
Joined: Jan 2024
Posts: 5
Likes: 0
Default
Thanks
Reply
0

Get notified of new replies

To C4 Transmission issue

Back to Subforum
C4 Tech/Performance
View Next Unread
vacuum question




Click for Advanced Search
Reply Closed Thread Share
Forum Jump
Trending Topics

All times are GMT -4. The time now is 06:08 AM.

story-0
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-1
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
story-2
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-3
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-4
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-5
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-6
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-7
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-8
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-9
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE