Corroded Stabilizer Bar: How Bad Is It?

[IPreferDIY]

My car (a 2000 Grand Marquis LS) developed various suspension and steering issues by about 170,000 km. I’ve talked about my rebuild experiences in the following two threads:

http://www.grandmarq.net/vb/showthread.php?51153-Creaking-squealy-grating-sound-coming-from-front-underneath-car

http://www.grandmarq.net/vb/showthread.php?50937-Looking-at-control-arms-on-Rock-Auto-How-do-I-know-if-I-have-a-handling-package

It turned out that the stabilizer bar bushings needed to be replaced after everything else, and I did that yesterday.

Getting the correct bushings was a bit of a pain since there are various sizes. My bar is straight between the bushings and measures 28.5mm in that area. The correct bushings were apparently 8732's, which were listed as being for a 28.5mm to 29.5mm bar. This would have been fine enough, but Moog recently changed part numbers. Now they have 200167's, which are typically listed as being for a 28mm bar, and 200168's, which are typically listed as being for a 29 to 29.5mm bar. I ended up getting a cheap brand of 8732 bushings. The bushings themselves actually indicate they are 29mm.

When I got the bar and bushings off, I was horrified to see a very thick version of the flaky rust problem. After getting it all off and wire brushing the bar, I had some curious measurements. Right beside the expanded ring part of the bar where the bushing sits, I measured 29.5mm. Moving across the bushing area, the diameter went down to 28.5mm, and then plummeted to 27mm at its lowest point. I have attached photos of these parts of the bar showing how badly the bar had been corroded.



Is the part of the bar where the bushings sit supposed to be a uniform diameter?, or does it actually have some kind of fancy taper?

Incidentally, one issue I couldn’t figure out beforehand was which direction the slit goes. I figured the old ones would tell me, and I was right. I have attached a photo of the bushings showing noticeable wear on the rear outer parts, suggesting the slit should be at the front. [The two marks at the 4 o’clock and 5 o’clock positions on the bushing on the left (from the passenger side) and at the 8:30 and 9:30 positions on the bushing on the right (from the driver’s side) were made by me with a hacksaw blade while the bushings were still on the bar so I would know the orientation after they were off. All the other problems are a reflection of how bad the bushings were.]

[85crownHPP]

I've noticed that box bars aren't exactly the same thickness, especially in the curved areas, I'd assume that's the way they are made. As long as your bushings fit snug I wouldn't worry. You could put some silicone grease on the bar there to help keep the rust down.

[IPreferDIY]

Well, I still have a little bit of the creaking sound after changing the bushings. I was hoping maybe the bar needed to 'settle in', but this seems like wishful thinking at this point. I'm figuring the new bushings will wear out very quickly, but that I should get at least a couple of years to find a decent bar at a decent price. Thankfully, the bushings themselves aren't expensive.

[sly]

meh... if it squeaks... lube it.

[johnunit]

Yep just put some grease there and it should all be good.

[Lincolnmania]

greaseable poly swaybar bushings are nice

[jaywish]

Should try those next time.

[gadget73]

Just make sure its rubber-compatible grease. White lithium and silicone grease usually don't turn rubber to goo.

[IPreferDIY]

I had actually used a crapload of grease when I installed them. I’d read a bit about the grease on rubber problems, but I just went with what I had, which was the blue lithium semi-synthetic grease. I have no idea what material the bushings were made from. They were “BAW” brand, and they were a hard blue material that ‘clacked’ when tapped together. I could have got the Moog brand for about $5 more, but that was poker money.

I’m guessing that when the old rubber ones got smooshed into the corrosion, this created some kind of sandpaper effect. I can get a bar at a U-pull-it yard for only about $40, but the trick will be finding a bar in decent shape. If I go on a “free parts day”, I can get all the parts I can carry unassisted for a flat entrance fee of $50. (Let’s see, stabilizer bar, front fenders, spare starter, ...)

There’s five reasons why I generally don’t bother with ‘premium’ parts. First, I’m cheap. Second, I don’t drive all that much. Third, certain ‘esoteric’ things are beyond my capability of appreciating. Fourth, what might seem like decent prices in the U.S. tend to be much higher in Canada. You folks are very lucky in that respect. When something is offered with free shipping in the U.S., we don’t even get the benefit of a discount on shipping. And we get dinged at customs for items over $20, whereas I think you folks get up to $200. So much for “free trade”. Fifth, rust is a huge problem up here for a year-round car like mine, so it’s hard to justify getting fancy when you don’t really know how much longer the car will last. For those of you who aren’t in the rust belt, you folks are hugely lucky.

[IPreferDIY]

... Getting the correct bushings was a bit of a pain since there are various sizes. My bar is straight between the bushings and measures 28.5mm in that area. The correct bushings were apparently 8732's, which were listed as being for a 28.5mm to 29.5mm bar. This would have been fine enough, but Moog recently changed part numbers. Now they have 200167's, which are typically listed as being for a 28mm bar, and 200168's, which are typically listed as being for a 29 to 29.5mm bar. I ended up getting a cheap brand of 8732 bushings. The bushings themselves actually indicate they are 29mm. ...

Well, I still have a little bit of the creaking sound after changing the bushings. I was hoping maybe the bar needed to 'settle in', but this seems like wishful thinking at this point. I'm figuring the new bushings will wear out very quickly, but that I should get at least a couple of years to find a decent bar at a decent price. Thankfully, the bushings themselves aren't expensive.

After a longer period of time, I was under the impression that the bar had indeed 'settled in'. But, something that came about was a funny feeling through the steering wheel in certain circumstances, along with a feeling of slop when doing right turns. The slop had been a lot worse before I started changing everything, so I figured what was left was from something that hadn't been changed. I'd read some stuff about bad steering shaft joints and figured that was the problem, but a recent inspection indicated the only slop in the steering was in the Pitman arm joint. I guess that'll teach me for using cheap Chinese parts. Some of the creaking also came back when the weather got warmer.

Something I noticed recently was that the stabilizer bar was almost as far to one side as it could go. I'm guessing the funny feeling is from the bushings being slightly too big and allowing the bar to move from side to side. The ones I got were probably for the 29.5mm bar. The next size down (Moog K200167) are sometimes listed as being for 27.8 to 28.5mm bars, so I'm going to give them a try. When ordering from RockAuto, the shipping alone was a little more than the cost of the bushings, but the total price is probably still less than what I can get them for locally if you factor in gas. I'll post the results when I change them. FWIW, here's a front stabilizer bar size chart from the late great 2vmod:

http://www.idmsvcs.com/2vmod/suspension/swaybars/front/partnumbers.html

[gadget73]

The bar really shouldn't move side to side. The bushings don't do much to hold it laterally anyway. it should pretty much center itself with the endlinks. The way the bar functions, I seriously doubt you'd ever feel it moving side to side. it works purely in torsion, which isn't particularly affected by where it sits. What you would tend to notice if the thing is seriously off center is increased wear on the end links. If you start chewing through them, that could well be the why.


A worn pitman arm would explain funny steering. Check the idler arm too. When one is bad, the other usually is too, though I understand yours are not so much a mileage wear thing as a crap quality part issue.

[IPreferDIY]

The bar really shouldn't move side to side. The bushings don't do much to hold it laterally anyway. it should pretty much center itself with the endlinks. The way the bar functions, I seriously doubt you'd ever feel it moving side to side. it works purely in torsion, which isn't particularly affected by where it sits. What you would tend to notice if the thing is seriously off center is increased wear on the end links. If you start chewing through them, that could well be the why. ...

That would make sense to me for the bars that are connected to the lower control arms, but wouldn't the bars connected to the spindles bring different things into play? Assuming there is side-to-side movement, I suppose I could be feeling the expanded ring part of the bar (apparently called a "centering ring") bumping into the bushing. (BTW, I've read about people with bars that don't have centering rings putting on shaft collars beside the bushings to prevent side-to-side movement.) With the bar shifted to one side, another possibility is that the bar might have vertical slop in one bushing due to the exaggerated taper from the corrosion. Such issues would presumably send detectable vibrations through the steering via the spindles. If nothing else, changing the bushings will make for a relatively simple experiment.

... A worn pitman arm would explain funny steering. Check the idler arm too. When one is bad, the other usually is too, though I understand yours are not so much a mileage wear thing as a crap quality part issue.

The idler arm seemed okay. Funny thing with the slop during right turns, even when it was really bad before I changed stuff, everything still felt tight when travelling straight. There's never been any centered steering slop in the sense of turning the wheel from the straight position and not getting any response from the wheels. I'll see what happens with the bushings first and go from there. I had used a lot of rust inhibitor when putting the Pitman arm on, so hopefully I won't have to resort to grinding this time.

[IPreferDIY]

Finally got around to replacing the stabilizer bar bushings with the next smaller size. Having a slightly bigger size seems to be what was causing all the problems. The ones that came out have obvious wear on them after little more than a year.

The weird stuff only happened in residential areas, and mostly when I was just starting out. Even going over the little bump at the end of the driveway (from the paving stones having sunk below the curb) on my way out tended to cause a noticeable sensation. Highway driving didn't have any noticeable issues.

The correct bushings are actually about 1/8" taller. The other ones were practically flush with the mounts while the correct ones protrude a little bit. Based on one drive, all the weirdness seems to be cleared up. I could definitely feel an overall improvement, even with highway driving despite the lack of prior obvious issues. It makes the little bit of slop in the Pitman arms seem like a non-issue at this point.

I read a comment on CVN awhile ago along the lines of someone speaking with an Energy Suspension rep and being told that 1mm makes a big difference. I guess it's true, though the 1/8" height difference must have been a big factor in my case.

In order to avoid having crud work its way into the space between the bushing and the stabilizer bar, I put a piece of vapor barrier between the mount and the bushing to serve as a deflector. I'll post pics later.

[IPreferDIY]

Well, the K200167's were definitely an improvement, but there were still issues. I decided to try the next size down, the K200166's, which are apparently for 27-27.8mm bars. During my initial test drives, there was further improvement, though there’s still something not quite right. Having a mounted camera view would be awesome (even if someone had one showing a normal bar), but that's beyond me at this point.

I have attached a few photos comparing the B&W brand of 168's (largest) and the Moog 167's. The first photo is intended to show the slight height difference. I recall checking the B&W brand against the Moog brand at the store with no apparent difference apart from Moog’s lack of a lip around the holes, so different brand doesn’t seem to account for the height difference. The second photo shows the 168's on top, and the ones on the left are the passenger side. The 168 on the passenger side got munched pretty bad. The third photo is pretty much the same but angled differently to show the driver’s side wear. A better bar is on my to-do list.



Here’s a photo showing how much the 166's had to get squashed:



And here’s a photo showing a piece of vapor barrier I used as a splash guard:



The wrinkling in the vapor barrier was enough to cause indentations on the bushings.

[gadget73]

Those don't look like the right bushings. You should have that bracket flat against the frame, not stood off like it is. The bushing should fully close too. That bar does need to move in the bushing. Having it clamped too much will not allow it to rotate, and it will shred those bushings out in short order.