1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Need to identify thunking/thud noise.

Thread Tools
 
Search this Thread
 
Old 03-01-04 | 04:19 AM
  #1  
University_seven's Avatar
Thread Starter
Full Member

 
Joined: Feb 2004
Posts: 72
Likes: 0
From: Charlotte, NC
Need to identify thunking/thud noise.

I noticed that while i was driving i heard a thud when switching from first to second gear. well, while i was driving i put a little too much gas in and heard a thud while switching into first. i noticed that going 30mph the car was loud and making a funny vibration. and when i switch gears it sounds like metal is scraping some times. or like i'm dragging something.... HELP!!!!!
Old 03-01-04 | 07:07 AM
  #2  
inittab's Avatar
I read your email
 
Joined: Jan 2002
Posts: 2,624
Likes: 1
From: NW New Jersey
Ah! It sounds like the classic case of dragging something. I'd look under the car to see what it is. I hope this helps.
Old 03-01-04 | 09:24 AM
  #3  
University_seven's Avatar
Thread Starter
Full Member

 
Joined: Feb 2004
Posts: 72
Likes: 0
From: Charlotte, NC
i tried that and i didn't see anything, for some reason the car rides smooth until 30mph even at high rpm it rides smooth. even if i have the clutch down it rumbles at 30 is it's not transmission nor engine but i don't know what it is
Old 03-01-04 | 09:42 AM
  #4  
GT3_racer's Avatar
Junior Member

 
Joined: Dec 2003
Posts: 34
Likes: 0
From: Ft Worth Tx
U joints are gone, maybe the rear end, its one of those
Old 03-01-04 | 09:44 AM
  #5  
MIKE-P-28's Avatar
Driven a turbo FB lately?
iTrader: (1)
 
Joined: Oct 2001
Posts: 6,444
Likes: 0
From: Fort Branch, Indiana
U joint is my guess... Replace both of them..
Old 03-01-04 | 09:54 AM
  #6  
Lee Lyons's Avatar
Rotary Enthusiast

 
Joined: Jun 2003
Posts: 1,288
Likes: 0
From: Calgary; AB
Ya but even still u joints don't make clunk noises when you change gears. It should just make your car feel really stiff or you might hear creaking noises. Or you might notice stearing is well to say the least shitty. But you could have possibly ground a gear and that clunk noise is it trying to catch up.
Old 03-01-04 | 10:54 AM
  #7  
inittab's Avatar
I read your email
 
Joined: Jan 2002
Posts: 2,624
Likes: 1
From: NW New Jersey
inspect the motor and transmission mounts
Old 03-01-04 | 01:29 PM
  #8  
Anex 570's Avatar
It Runs!
 
Joined: Aug 2003
Posts: 955
Likes: 2
From: PA
That really does sound like a U-joint problem. Lee Lyons your thinking of ball joints... If you dont do your own work a local shop can get the whole thing done well under $100 even less if you already have the parts, because they might not have them right away. There is a slight chance that it could be the rear end, but id change the u-joints first and go from there.
Old 03-01-04 | 01:56 PM
  #9  
ioTus's Avatar
'84 5-letter
iTrader: (5)
 
Joined: Jul 2002
Posts: 3,219
Likes: 7
From: Washington State
metallic_rock's car had this happen to his. He'd shift and you'd hear a clunk, and it would vibrate at higher speeds.

One of the bolts on his driveshaft was different size, and was throwing off the balance. make sure all the bolts are in place and everything. Make sure it isnt broken .
Old 03-01-04 | 03:08 PM
  #10  
Cody's Avatar
SKELETOR!
 
Joined: Mar 2003
Posts: 1,077
Likes: 0
From: Prescott Valley, AZ
SAme thing happened to me once..

Turned out, I just hit some little kid on a goped.
Old 03-01-04 | 04:41 PM
  #11  
John64's Avatar
What?
 
Joined: Sep 2003
Posts: 3,833
Likes: 1
From: CT
It only hapens when you shift gears? Just don't shift, 7's can go up to 12000-25000 RPM's right?
The smoke and sounds are normal at thost high RPM's.
Old 03-01-04 | 05:14 PM
  #12  
University_seven's Avatar
Thread Starter
Full Member

 
Joined: Feb 2004
Posts: 72
Likes: 0
From: Charlotte, NC
i took it for another drive and it shakes at 30 mph and when i switch gears, as i let out the clutch i hear a rattling. i'm affriad its the transmission! ****!
Old 03-01-04 | 05:26 PM
  #13  
Anex 570's Avatar
It Runs!
 
Joined: Aug 2003
Posts: 955
Likes: 2
From: PA
Ok, please listen to me, or theres no real sense in this post. You need to replace the U-joints on the drive shaft no matter what, they're now brand new and they're prolly all toasted. Thats where your play is coming from. The axle still spins even if you let the clutch in. It'll only take a little time to get it done, and after that if theres still a problem, you can get your tranny and rear end looked at.
Old 03-01-04 | 06:51 PM
  #14  
enigma32's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Sep 2002
Posts: 686
Likes: 0
From: Central New York
I had the same problem with mine this past summer and it was indeed the U-joints. It's easy enough to check and be sure... Just climb under there and wiggle the driveshaft and watch the play in the joints.
Old 03-01-04 | 07:32 PM
  #15  
Lotus00's Avatar
Senior Member
 
Joined: Jun 2002
Posts: 558
Likes: 0
From: Minnesota
yeah, definatly a u-joint. when mine went it did the same thing, even the "clunk" when shifting. I think that is just the joints slaming into the holes they are in on the driveshaft. Just get some new u-joints, they are like $40 from mazda.
Old 03-01-04 | 11:08 PM
  #16  
hornbm's Avatar
FD > FB > FC
 
Joined: Oct 2002
Posts: 3,873
Likes: 3
From: Bothell, WA
What year is it? The 81's and up have a non replaceable u-joint on the drive shaft. You have to replace the whole shaft, its like 300 bucks from mazda.

My reccomendation is to go to mazdatrix and buy one of their driveshafts. They are better construction than the origionals, cost less (about $220) and have replaceable u-joints. I have one on my car now and it kicks ***!
Old 03-01-04 | 11:13 PM
  #17  
Lotus00's Avatar
Senior Member
 
Joined: Jun 2002
Posts: 558
Likes: 0
From: Minnesota
I have an 82 and I replaced the u-joints on it. I think I have a mazdatrix driveshaft though...
Old 03-01-04 | 11:27 PM
  #18  
KehoeAutomotive's Avatar
Senior Member
 
Joined: Jan 2004
Posts: 505
Likes: 2
From: New Orleans, LA
U joints are cheap and easy to install.

Just consider replacing them as the first step in he diagnosis.
Old 03-01-04 | 11:29 PM
  #19  
University_seven's Avatar
Thread Starter
Full Member

 
Joined: Feb 2004
Posts: 72
Likes: 0
From: Charlotte, NC
yeah i have an order form from victoria someting or other they have u-joints seperate for my 82
Old 03-02-04 | 12:19 AM
  #20  
hornbm's Avatar
FD > FB > FC
 
Joined: Oct 2002
Posts: 3,873
Likes: 3
From: Bothell, WA
woops, its 83 and up not 81, my bad
Old 03-04-04 | 11:37 AM
  #21  
LaRazaUnida's Avatar
Senior Member
 
Joined: Jul 2003
Posts: 648
Likes: 0
From: North Texas
right now my car has the exact same problem. Its an 85-GSL SE. So im going to have to replace the whole shaft because the Ujoints dont come seperate for that model?? Also I need a new rear end for my car(found one for 150). She shakes and rumbles when i drive...mmm the vibrations. lol.
Old 03-04-04 | 11:46 AM
  #22  
mx5rx7girl's Avatar
Senior Member
 
Joined: Apr 2001
Posts: 428
Likes: 0
From: Lubbock, TX
Originally posted by Anex 570
You need to replace the U-joints on the drive shaft no matter what, they're now brand new and they're prolly all toasted. Thats where your play is coming from. The axle still spins even if you let the clutch in.
I agree. What happens when u-joints are bad (lose, wobbly) is when the load is taken off the drivetrain (shifting) the slack is allowing the units to wobble around again, causing the clunk or vibration.
Old 03-04-04 | 11:50 AM
  #23  
mx5rx7girl's Avatar
Senior Member
 
Joined: Apr 2001
Posts: 428
Likes: 0
From: Lubbock, TX
Originally posted by LaRazaUnida
...mmm the vibrations. lol.
Old 03-04-04 | 12:39 PM
  #24  
hotty's Avatar
Rotary Enthusiast
 
Joined: Oct 2001
Posts: 898
Likes: 0
From: T.O
Like EVERYONE said, its the driveshaft/U-joints. I would goto a wrecking yard if you dont have much money, otherwise do what horn said, and get the mazdatrix.
Old 03-04-04 | 04:00 PM
  #25  
University_seven's Avatar
Thread Starter
Full Member

 
Joined: Feb 2004
Posts: 72
Likes: 0
From: Charlotte, NC
twas the u joints for the rumbling got it fixed but for some reason the fire wall was missing a bold and that was the rattling, i have some rumbling from my back end too(car not my actual ***). might be because i need to new tires...thanks for the help



All times are GMT -5. The time now is 02:23 PM.