C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Vibration?

Thread Tools
 
Search this Thread
 
Old Apr 23, 2017 | 12:06 PM
  #1  
olelucky's Avatar
olelucky
Thread Starter
Instructor
20 Year Member
Active Streak: 30 Days
Liked
Loved
 
Joined: Jun 2003
Posts: 156
Likes: 12
From: Arkansas
Default Vibration?

I need some help tracking down a vibration. The vibration is rhythmic or intermittent, not constant. Its at its worse from 2800-3000. Which is 65-70 on the highway. Its not noticeable below that and not as bad above that. I ran it in 2nd gear and got the same vibration at same rpm. which tell me its not in the shafts or joints(not speed related). I feel like its in the trans. but don't know a way to check without pulling it. I ran it in park and neutral, didn't feel any vibration.
thanks

72 coupe, 350- 400 turbo
history, last fall pulled engine and trans to freshen up. I had motor gone thru and balanced. I had trans gone thru at the same time to freshen it up while everything was out. all new u-joints last fall also.
Reply
Old Apr 23, 2017 | 05:24 PM
  #2  
fishslayer143's Avatar
fishslayer143
Drifting
 
Joined: Aug 2009
Posts: 1,346
Likes: 160
From: new iberia la
Default

just a guess, because a vibration can be so many things, and it seems to be engine rpm specific, have you checked your Harmonic Dampener?
Reply
Old Apr 23, 2017 | 05:44 PM
  #3  
olelucky's Avatar
olelucky
Thread Starter
Instructor
20 Year Member
Active Streak: 30 Days
Liked
Loved
 
Joined: Jun 2003
Posts: 156
Likes: 12
From: Arkansas
Default

thanks fishslayer, I visually checked it as it was running and didn't see any wobble. Is there another method to check it?
Reply
Old Apr 23, 2017 | 06:03 PM
  #4  
John 65's Avatar
John 65
Le Mans Master
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2003
Posts: 5,380
Likes: 415
From: N J
Default

When I swapped from auto to manual, the lack of shims at the rear trans mount caused a vibration. Raised it slightly, slid 2 shims in and the vibration went away. Just a thought. Good luck.
Reply
Old Apr 23, 2017 | 07:25 PM
  #5  
olelucky's Avatar
olelucky
Thread Starter
Instructor
20 Year Member
Active Streak: 30 Days
Liked
Loved
 
Joined: Jun 2003
Posts: 156
Likes: 12
From: Arkansas
Default

I'll try that John, thanks
Reply
Old Apr 23, 2017 | 08:04 PM
  #6  
VERYSOON's Avatar
VERYSOON
Burning Brakes
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2001
Posts: 916
Likes: 196
From: TX
Default

Check your water pump. Never leaked a drop until total failure. I first noticed vibration around 3000 rpm. Ignored it. Got lucky!!
VERYSOON
Reply
Old Apr 23, 2017 | 11:58 PM
  #7  
theandies's Avatar
theandies
Team Owner
20 Year Member
Veteran: Air Force
Community Favorite
Top Answer: 1
 
Joined: Jun 2001
Posts: 23,353
Likes: 1,054
From: Virginia USA
Default

Originally Posted by VERYSOON
Check your water pump. Never leaked a drop until total failure. I first noticed vibration around 3000 rpm. Ignored it. Got lucky!!
VERYSOON
Thats what I was thinking. I have a similar vibration and when I had the engine and transmission out last fall I noticed my Edlebrock water pump seemed seized up when I was putting it back on. I sprayed some PB blaster into the impeller area and it came loose so I installed it. I think that was a mistake and I should have put a new pump on as I can grab the WP pulley and feel a little play when moving it like when you check wheel bearings. I have an old cast iron pump that I'm going to try and if that's it I'll spring for a new aluminum pump.
I'm also thinking about taking the drive shaft out and have it balanced just to eliminate that.
Reply
Old Apr 24, 2017 | 07:27 AM
  #8  
fishslayer143's Avatar
fishslayer143
Drifting
 
Joined: Aug 2009
Posts: 1,346
Likes: 160
From: new iberia la
Default

Originally Posted by olelucky
thanks fishslayer, I visually checked it as it was running and didn't see any wobble. Is there another method to check it?
check to see that the outer ring has not detached and moved out of position.. it can cause out of balance vibration.. as suggested check your waterpump shaft for play, but usually it will leak water if its failing . a bent fan blade can do it too. being its rpm specific and not speed ,its probably nothing in drivetrain..you say you had Trans rebuilt, so probably not input shaft bearing. I would concentrate on engine .. But vibrations can be deceiving and a bitch to isolate.. good luck
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

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

 Michael S. Palmer
story-1

2027 Corvette vs The World: Every Model vs Closest Competitor

 Joe Kucinski
story-2

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
story-3

5 MOST and 5 LEAST Popular Corvette Model Years in History!

 Joe Kucinski
story-4

2027 Corvette Buyer's Guide: Everything You Need to Know!

 Joe Kucinski
story-5

10 Things C8 Corvette Owners Hate (But Won't Tell You)

 Joe Kucinski
story-6

10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

 Brett Foote
story-7

Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

 Joe Kucinski
story-8

Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

 Michael S. Palmer
story-9

5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

 Joe Kucinski
Old Apr 24, 2017 | 07:11 PM
  #9  
Jartanyon's Avatar
Jartanyon
Racer
10 Year Member
 
Joined: May 2013
Posts: 421
Likes: 6
From: Chicago IL
Default

I had a similar vibration like that within a certain rpm...turned out to be a loose power steering belt.
Reply
Old Apr 24, 2017 | 10:19 PM
  #10  
Spoticus's Avatar
Spoticus
Intermediate
 
Joined: Sep 2014
Posts: 45
Likes: 9
From: Queensland
Default

Had a vibration at those RPMs on my 78. Mine would shake the gear stick and make it rattle but I could make it happen by just revving the engine in neutral.

While diagnosing I removed the mechanical fan on the front of the motor and it went away.
Never put it back on and went to electric fans. Problem fixed.
Reply
Old Apr 25, 2017 | 07:39 PM
  #11  
spedaleden's Avatar
spedaleden
Safety Car
20 Year Member
 
Joined: Nov 2004
Posts: 4,359
Likes: 57
From: Mundelein Illinois
Default

Also check trans mount, they start to pull apart as time goes on. Maybe when you did motor and trans you put new mounts in?
Reply
Old Jun 11, 2017 | 04:54 PM
  #12  
olelucky's Avatar
olelucky
Thread Starter
Instructor
20 Year Member
Active Streak: 30 Days
Liked
Loved
 
Joined: Jun 2003
Posts: 156
Likes: 12
From: Arkansas
Default

update: I may have found the culprit. Friday i was headed to a corvette gathering about 225 miles away. At mile 170, the transmission gave out, low gear only(turbo 400). When it would try to shift into 2nd it would slip and rev up.
Last fall I had my engine out for gasket leak repairs and updates. While it was out, I took my trans to a local recommended shop for inspection and check-up. It had been working fine, but was 45 years old and should be looked at. When i put it back in, it didn't shift right. I took the car to same trans shop. He called and said it had shaving in it and had to be removed and fixed (again). He did, but I never felt it was right. This is why I've thought the vibration may have been in the trans. So I will replace this trans and then we will know if thats where the vibration was.
Reply
Old Jun 11, 2017 | 06:00 PM
  #13  
gjohnson's Avatar
gjohnson
Drifting
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Mar 2008
Posts: 1,797
Likes: 422
From: Denver CO
Default

I had a similar problem which was a pulsating vibration @ 60 mph.Problem solved when I put new wheels on.Must of had a bad rallye
Reply

Get notified of new replies

To Vibration?





All times are GMT -4. The time now is 03:01 AM.

story-0
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-1
2027 Corvette vs The World: Every Model vs Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-20 17:58:41


VIEW MORE
story-2
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
story-3
5 MOST and 5 LEAST Popular Corvette Model Years in History!

Slideshow: 5 most and least popular Corvette model years.

By Joe Kucinski | 2026-04-08 13:25:01


VIEW MORE
story-4
2027 Corvette Buyer's Guide: Everything You Need to Know!

Slideshow: 2027 Corvette buyer's guide

By Joe Kucinski | 2026-04-17 16:41:08


VIEW MORE
story-5
10 Things C8 Corvette Owners Hate (But Won't Tell You)

Slideshow: 10 things C8 Corvette owners hate, but won't tell you.

By Joe Kucinski | 2026-04-01 18:36:07


VIEW MORE
story-6
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

Slideshow: Should you add one of these incredible Corvettes to your garage?

By Brett Foote | 2026-04-01 18:14:05


VIEW MORE
story-7
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

Slideshow: Every Corvette Grand Sport explained

By Joe Kucinski | 2026-03-26 07:13:44


VIEW MORE
story-8
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

Slideshow: Breaking down the 2027 Grand Sport, Grand Sport X, Stingray, and LS6 V8.

By Michael S. Palmer | 2026-03-26 13:48:45


VIEW MORE
story-9
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

Slideshow: 5 reasons bad drivers crash sports cars & 5 ways to avoid a costly shame!

By Joe Kucinski | 2026-03-25 16:32:55


VIEW MORE