Rear-End clunk - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars
Ford Forum Ford Forum

» Auto Insurance
» Featured Product
ยป Wheel & Tire Center

Go Back   Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > Ford Cars and PAG Vehicles > Ford Crown Victoria | Mercury Marauder | Grand Marquis | P71
Register Home Forum Active Topics Photo Gallery Auto Loans Garage Mark Forums Read Auto Escrow

Ford Crown Victoria | Mercury Marauder | Grand Marquis | P71 Forum for discussion of the Ford Crown Victoria, Mercury Marauder, Mercury Grand Marquis and P71.

FordForums.com is the premier Ford Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
Old 03-23-2010, 15:09   #1 (permalink)
Registered User
 
Join Date: Mar 2010
Location: Eastpointe, MI
Posts: 107
Rear-End clunk

Ever sense I got my tires replaced last August, my car has had a very annoying and loud clunk from the rear passenger aria of the car. Every time I jack up the rear end of the car but don't support the diff it will get worse for a couple of days before going back to normal (still clunking). 3 days before I got the tires, I had replaced the shocks with Monroe Sensa-Track's.

I have since ruled out:
-stuff in the trunk
-any thing in the diff(bearings, axles, gears),
-shocks(swapped side to side, no affect)
-sway bar bushings and endlinks(replaced)
-wheels/tires(rotated front to back)

it makes this noise when I take off from a stop, or driving over a bump where one wheel is higher than the other. That is what made me think it was sway bar bushings. When I was swapping the shocks side to side I noticed one was softer than the other, but not by much.

So now I am thinking control arm bushings, but I have never herd of them failing before. what do you guys think?

96 Mercury Grand Marquis GS
BigMerc96 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 03-25-2010, 12:23   #2 (permalink)
Registered User
 
Join Date: Jun 2005
Posts: 36
Re: Rear-End clunk

It sounds like your u-joint is going bad. Have you checked it?
jeririah is offline   Reply With Quote
Old 03-25-2010, 12:58   #3 (permalink)
Registered User
 
Join Date: Mar 2010
Location: Eastpointe, MI
Posts: 107
Re: Rear-End clunk

Yea I forgot about that, the u-joints were one of the first things I checked and they seems to be fine. Plus, wouldn't a u-Joint make noise/vibration while driving on the highway? When i bought the car I was told that it had been sitting for about three years, and in that time it had been leaking fluid from the diff cover. After driving it 100mi home i pulled the cover to find VERY little fluid in it, and no cover gasket of any sort. Every thing looked OK though and there was no excessive wear that i could find. So I'm pretty sure this noise is comeing from somewhere in the suspension but I don't know from where. Thanks for the reply, Any other thoughts?

-Steve
BigMerc96 is offline   Reply With Quote
Old 03-25-2010, 13:53   #4 (permalink)
2002 F150 XLT
 
Bert's Avatar
 
Join Date: Nov 2008
Location: Oregon
Posts: 9,886
Re: Rear-End clunk

Can you make the noise by rocking it setting still or do you have to be moving? When you jack it up, do you hear any noise?
__________________
Bert
Bert is offline   Reply With Quote
Old 03-25-2010, 15:14   #5 (permalink)
Registered User
 
Join Date: Mar 2010
Location: Eastpointe, MI
Posts: 107
Re: Rear-End clunk

I have been able to make it make the noise while rocking it, but only once, and of course i wasn't expecting it so I wasn't able to pinpoint it, and I haven't been able to make it do it since(except wile driving of course).

When I let down the back passenger side of the car off the jack and the drivers side is already down, it has made the sound a few times, but only if i let it down quickly.

It seems that it likes to make this sound if there is some sort of side load on the car while going over bumps, like while going around a corner on the terrible Michigan roads.

All signs seem to point to sway bar bushings, and that is why I replaced them last October. They were bad anyway, the end-link bushings disintegrated when I was removing them, but that did not effect this noise at all(much to my disappointment, I really thought that was going to fix it it).

-Steve
BigMerc96 is offline   Reply With Quote
Old 03-25-2010, 15:47   #6 (permalink)
2002 F150 XLT
 
Bert's Avatar
 
Join Date: Nov 2008
Location: Oregon
Posts: 9,886
Re: Rear-End clunk

Another thing to try, is to push the rear side, like you could push the car sideways, as if the rear wheels could slide sideways. Rock it back and forth to see if it makes the noise. The newer Crown Vics had cracks in the mounts where the control arms were welded to the body. Your year wasn't included but with th rust in your area, it could have a bearing on the problem. Though the left side rusts more than the right. My family lives near Traverse City, which I did until I was 18 and left, so I'm familiar with the rust problems.
__________________
Bert
Bert is offline   Reply With Quote
Old 03-25-2010, 17:27   #7 (permalink)
Registered User
 
Join Date: Mar 2010
Location: Eastpointe, MI
Posts: 107
Re: Rear-End clunk

Thanks Bert, I'll have to give that a try, and post back.
I knew that they made reinforcing plates for the newer crown vics, but I didn't know why, good to know.

I don't think that rust is too much of an issue on my car, unlike my last car, this car has been very well maintained by its previous owners. It was garage kept its whole life and is very rust free for a MI car, thats one of the reasons I bought it. Plus its only got 83,000 miles on it.
BigMerc96 is offline   Reply With Quote
Old 03-25-2010, 18:42   #8 (permalink)
Registered User
 
Join Date: Aug 2008
Location: Toronto Canada
Posts: 89
Re: Rear-End clunk

With your diff problems with low oil I am thinking pinion bears are dryed out and near separation. Jack the car up use jack stands and block the wheels. Grab the pinion yoke (were the drive shaft bolts on) and try moving it in all directions. Undo the drive shaft and try turning the yoke to feel any binding at rotation. If it moves up or down or side ways at all you need another diff or rebuild.
Stick462 is offline   Reply With Quote
Old 03-25-2010, 20:46   #9 (permalink)
Registered User
 
Join Date: Mar 2010
Location: Eastpointe, MI
Posts: 107
Re: Rear-End clunk

Tomorrow I'm going to be working on the car so I'll check on that while I'm at it, thanks for the reply, I really hope I don't need a new diff. Wouldn't that also make a more constant noise as opposed to just the clunk?

After I refilled the diff and added the missing cover gasket, I drove for about a month and ~1000mi before this noise started. I have also been keeping an eye on the fluid level sense then and it hasn't dropped at all so it's not leaking anymore.

I had some passengers in the back seat today, and they told me that when it goes BANG they can feel it in the seat, but I cannot feel it from the drivers seat.

-Steve
BigMerc96 is offline   Reply With Quote
Old 03-26-2010, 10:11   #10 (permalink)
Registered User
 
Join Date: Aug 2008
Location: Toronto Canada
Posts: 89
Re: Rear-End clunk

When you had the cover off did you rotate the crown and pinon to check for a broken tooth. Does this rear have a positraction ?? If it has a posi did you put friction modifyer in with the gear lube??
Stick462 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

  Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > Ford Cars and PAG Vehicles > Ford Crown Victoria | Mercury Marauder | Grand Marquis | P71



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 On
Pingbacks are On
Refbacks are On


Powered by vBadvanced CMPS v3.2.2

All times are GMT -7. The time now is 15:54.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.6.0
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.