Need help re: rear suspension noise

[Fourth Horseman]

Hey all,

As you know I've been battling the rear suspension popping noise when turning into driveways and through gutters and such. I got my car back today from its second trip to the dealer to try and solve the problem. Result: they still can't fix it.

Anyway, what I have a question about is the size of the rear sway bar. One of the things they did was to replace the bar, links and bushings. When I scurried under the car tonight to take a look I thought the bar looked a little small, but couldn't remember what the old one looked like. I put a pair of calipers on the bar to measure the diameter and it measure 15mm. Everything I've read says the bar should be 21mm. I'm not positive I'm doing this right, but shouldn't the size listed for the bar be of it's maximum diameter?

The part number they say they ordered was 5A772-AA, my shop manual says the part number should be 5A771.

Am I just being paranoid? Are those really the same thing, maybe just a newer version? It's not possible they put a regular Grand Marquis sway bar on my car is it?

You all are much more experienced with this stuff than I am so I'm hoping to hear what you think. Thanks.

[RCSignals]

I think the bar is supposed to be the 21 mm you mention.
15mm sounds like one off a HPP CV or GM, but I'm only going by memory from what I've read

Have they tried the TSB axle bearing change that was mentioned?

[MM03]

Fourth

I got to the shop early so I measured the rear bar. It measures 21 mm. My MM is a 300a. Hope this helps.

[WolfeBros]

It is sure sounding fishy to me.
Time to grab the SM by the short hairs and have him explain what the heck they are doing to YOUR car and why before they do it.:mad:

[Matt Johnson]

i've noticed this too, now, (after reading about it and turning the stereo down to listen as I pull into my driveway) and I'm just not alarmed by it at all.

seems so common here, that it must be the sound of the airbag suspension in the rear, or something as innocuous. doesn't sound like anything's "wrong" with the car, and some of you guys who have reported this sound on the forum have many more miles on your rides than myself and are still going strong.

[SergntMac]

You can look up your suspension specs here;

www.mercuryvehicles.com/vehicles/marauder/all_specs.asp

[frdwrnch]

Noise problems are almost impossible to diagnose w/o being there due to there subjective nature. It's usually an educated process of elimination when your chasing these problems. Here are some things to check: Retorque all suspension attachments (trailing arms, watts link center and ends and sway bar ataching points); Check sway bar for side to side movement , can be eliminated by putting hose clamps on bar next to pivot bushings,
check parkbrake cable routing, it can bind in the routing loops and then pop when it frees, lube and rerooute as necessary; check to see if rear brake caliper is sticking on slide; and in some rare instances I have seen popping from the body bushing in front of either of the rear wheels. In order to check for this the car must be on a lift, then remove the body to frame attaching bolts on the side in question from behind the front wheel back to the trunk area. Then carefully using a block of wood or rubber block on a screw jack raise the body about 1.5 inches to remove the bushing from between the frame and the body. If this was the concern there are usually witness marks on the flat (frame) side of the bushing. This really only takes about 20 minutes. Lube bushing and reinstall. Hope this helps.

[Fourth Horseman]

Originally posted by RCSignals
Have they tried the TSB axle bearing change that was mentioned?

Does anybody know what the TSB number for this axle bearing issue was?

[Black Terror]

03-5-5 is number for Rear Axle Bearing problems.

[RF Overlord]

Anyone been able to find out what build dates are affected by the bearing problem?

[Black Terror]

Article No.
03-5-5 AXLE - REAR AXLE SHAFT AND/OR AXLE BEARING PREMATURE WEAR - VEHICLES PRODUCED BEFORE 1/1/2003 ONLY

[RF Overlord]

Thank you, sir.

[Fourth Horseman]

Thanks for the info, team. This site is a great resource, as always.

I stopped in to my dealership's service center today to confirm the wrong sway bar was put on my car. Sure enough, they put the 15mm bar on there instead of the 21mm bar. The right part is on order and should be installed later this week.

When I go in for that I'll querry them on that TSB about the rear axle. Thanks again for all the help, folks! You rock!

[jgc61sr2002]

Originally posted by Fourth Horseman
Thanks for the info, team. This site is a great resource, as always.

I stopped in to my dealership's service center today to confirm the wrong sway bar was put on my car. Sure enough, they put the 15mm bar on there instead of the 21mm bar. The right part is on order and should be installed later this week.

When I go in for that I'll querry them on that TSB about the rear axle. Thanks again for all the help, folks! You rock! Excellent observation. John:up:

[JamesHecker]

Man, you read a thread like this and you can see how valuable this site is.

The site itself and the people that visit it are an incredible resource.

[Beadhead]

I've had the same "popping" noise problem for about a year and a half (see my prior thread on this issue). The dealer replaced a body mount bushing, which helped a little but did not cure the problem. The same dealer then installed a bolt through the frame on each side, just forward of the kick up over the rear axle. This cured about 75% of the popping, The dealer then welded the bolts to the frame, which had no further effect. The frame still "pops" every time I turn into my driveway! I am going to return to the dealer and request that they re-examine all of the body mount bushings, suspension bushings and all of the control arm welds. I will let you know the outcome.

Please let me know if you find a cure with yours.

P.S.: Have you checked the torque on the Watts linkage where it bolts up to the frame? A good tightening seemed to cure some other members' noise problems.

[Fourth Horseman]

I've had the same "popping" noise problem for about a year and a half (see my prior thread on this issue). The dealer replaced a body mount bushing, which helped a little but did not cure the problem. The same dealer then installed a bolt through the frame on each side, just forward of the kick up over the rear axle. This cured about 75% of the popping, The dealer then welded the bolts to the frame, which had no further effect. The frame still "pops" every time I turn into my driveway! I am going to return to the dealer and request that they re-examine all of the body mount bushings, suspension bushings and all of the control arm welds. I will let you know the outcome.

Please let me know if you find a cure with yours.

P.S.: Have you checked the torque on the Watts linkage where it bolts up to the frame? A good tightening seemed to cure some other members' noise problems.

Hi Beadhead,

It turned out that most (if not all) of my rear supsension noise was the shocks. I eventually heard a loud pop one day when pulling through a gutter. This pop was much louder than any before it. The next morning when I went out to my car there was a small puddle of oil underneath the left-rear shock. Yup, the shock had broken. I went into my dealer and had both rear shocks replaced with stock parts and I haven't heard a peep out of my rear supsension since.

Can't say this is the case with everybody who's had this issue, but the shocks turned out to be the culprits for me. Good luck.

[ckadiddle]

I get klanks and klunks from the rear when turning into certain driveways at certain angles. No "pop" noises though.