Noise Under truck when going over bumps - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > YJ Jeep Wrangler Forum > YJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 05-31-2009, 09:34 PM   #1
Newb
 
Join Date: May 2009
Posts: 4
Noise Under truck when going over bumps

Hi i have a 1987 Jeep Yj this is my first jeep so I dont know to much about them and need some help. It seems that every time i go over a big bump there is a noise sounding like steel hitting the bottom of my truck right between the front seats. Some times the noise just clunks other times it will sound like it grinds a little? It seems to only really do then when the truck is reved up past 3000 RPM...or if im giving lots of gas into the next gear...or if it is a really big bump? Could someone please help me diagnose the problem and tell me what it may be or is it just normal?

0eric01 is offline   Quote Quick Reply
Old 05-31-2009, 09:37 PM   #2
Jeeper
 
Join Date: Apr 2009
Posts: 538
when cooled down crawl underneath and hit muffler with your palm firmly. im thinking cat converter

dooder is offline   Quote Quick Reply
Old 05-31-2009, 09:43 PM   #3
Jeeper
 
buckshot500's Avatar
 
Join Date: Mar 2009
Location: Carolina
Posts: 798
Well Coming from the hump between the front seats, sounds like motor/trans mounts.

Your driveline is torquing, & twists with every shift. Prolly causing the trans, or transfer case to hit the tub. The two engine mounts up front, are a little tricky & may need to be pried into place. I haven't done my trans mount, as it was in good shape.

That mount might be a little harder to do, as you have to jack up the transmission, but you have to jack up the motor to do the front mounts anyway.
__________________
90YJ 98XJ
buckshot500 is offline   Quote Quick Reply
Old 06-01-2009, 12:25 PM   #4
Jeeper
 
yburn's Avatar
 
Join Date: Apr 2009
Location: Bethany IL
Posts: 203
I got the same prob i crawled under and pushed up on the motor and trans and muffler.Everything seems tight,so if you figure it out let me know!!
__________________
o4 rubicon,5.5 rubicon long arm lift,full cage,4:88 gears,37"Irocks
yburn is offline   Quote Quick Reply
Old 06-01-2009, 01:30 PM   #5
Jeeper
 
NAVYCHIEF's Avatar
 
Join Date: Sep 2008
Posts: 2,207
at 35,00 my 95 yj had a cat problem. the innards had come loose. it made a clunking noise. had to replace it.
__________________
1994 RENEGADE

TREAT EVERY STRESSFUL SITUATION AS A DOG WOULD.
IF YOU CAN'T EAT IT OR PLAY WITH IT,
JUST PEE ON IT AND WALK AWAY.
NAVYCHIEF is offline   Quote Quick Reply
Old 06-01-2009, 08:21 PM   #6
Jeeper
 
buckshot500's Avatar
 
Join Date: Mar 2009
Location: Carolina
Posts: 798
When my cat core broke up, it sounded like that old school toy for toddlers.
It was a sort of clear plastic tube on a stick with wheels.

When you rolled it, marbles would pop around inside it. Fischer-Price made it.

Look for chunks of ceramic honeycomb behind where you park.
__________________
90YJ 98XJ
buckshot500 is offline   Quote Quick Reply
Old 06-02-2009, 06:41 PM   #7
Newb
 
Join Date: May 2009
Posts: 4
Well went underneath checked the tranny and engine mounts...The tranny mounts where completly shot so I believe i knwo the problem...thanks for the help!!
0eric01 is offline   Quote Quick Reply
Old 06-02-2009, 06:48 PM   #8
Jeeper
 
Join Date: Apr 2009
Posts: 538
Quote:
Originally Posted by dooder View Post
when cooled down crawl underneath and hit muffler with your palm firmly. im thinking cat converter
or it could just be the mounts.
dooder is offline   Quote Quick Reply
Old 06-02-2009, 07:25 PM   #9
Jeeper
 
buckshot500's Avatar
 
Join Date: Mar 2009
Location: Carolina
Posts: 798
Quote:
Originally Posted by 0eric01 View Post
Well went underneath checked the tranny and engine mounts...The tranny mounts where completly shot so I believe i knwo the problem...thanks for the help!!
Let us know if it was difficult to do!

__________________
90YJ 98XJ
buckshot500 is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Clunk Noise Under Jeep fujiball TJ Tech Forum 15 08-04-2010 10:50 AM
clunking noise when hitting bumps? localjoey TJ Tech Forum 11 02-06-2008 08:28 PM
Whining Noise From Front Axle nicolas-eric TJ Tech Forum 35 01-27-2008 07:48 PM
ping noise when putting in park -please help phurl JK Tech Forum 2 12-06-2007 05:58 PM
The work truck 4point Off-Topic 15 07-15-2007 09:46 PM



» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 02:43 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC