Stabilizer links just don't fit snugly...?
10-20-11, 10:37 AM
#1
Rookie
Thread Starter
Stabilizer links just don't fit snugly...?
Hi folks, I have had an annoying clunk in the front end of my '99 since I bought it at the beginning of the year. Unfortunately I threw a couple parts at it that it didn't need because I couldn't reproduce the clunk either with the car parked (i.e., pushing it by hand) or with the suspension unloaded in the air.
I did trace it back to the sway bar links. I removed them then strung up the stabilizer bar to the springs using bungee cords and took it for a drive to confirm that. Here's the rub: I've tried two sets of aftermarket links produced by two different manufacturers; the suspension is beautifully quiet for a few drive cycles, but then the clunk returns. The reason is that the neck of the ball joints doesn't completely "fill" the square apertures in either the sway bar itself, or in the lower control arm. The neck of the ball joint is too skinny so there's play between the neck of the ball joint and the metal it's passing through. When the body of the car leans or one wheel rolls over rough road, it starts tugging at the sway bar, and that play around both ball joints is what's causing the clunk.
I've tried cranking down the stupid nuts with a 1,000 lb-ft air wrench, a breaker bar with a pipe, I've put on new grade 8 locknuts, heavy locking washers, AND slathered it with red loktite, and it still just won't stay tight enough to clamp down the ball joint sufficiently to prevent play after a few drive cycles.
Has anyone else observed this? I discarded the old links too quickly and now I don't know if they would be any different, but it's an expensive question to answer since the OEM links cost $100 per side. I'm not even sure if I'm supposed to do something different to "fill the gap" between the ball joints and the metal aperture they pass through...
Any experience or thoughts along these lines? Has anyone else had good luck with any brand of aftermarket links?
Thanks,
Andy
I did trace it back to the sway bar links. I removed them then strung up the stabilizer bar to the springs using bungee cords and took it for a drive to confirm that. Here's the rub: I've tried two sets of aftermarket links produced by two different manufacturers; the suspension is beautifully quiet for a few drive cycles, but then the clunk returns. The reason is that the neck of the ball joints doesn't completely "fill" the square apertures in either the sway bar itself, or in the lower control arm. The neck of the ball joint is too skinny so there's play between the neck of the ball joint and the metal it's passing through. When the body of the car leans or one wheel rolls over rough road, it starts tugging at the sway bar, and that play around both ball joints is what's causing the clunk.
I've tried cranking down the stupid nuts with a 1,000 lb-ft air wrench, a breaker bar with a pipe, I've put on new grade 8 locknuts, heavy locking washers, AND slathered it with red loktite, and it still just won't stay tight enough to clamp down the ball joint sufficiently to prevent play after a few drive cycles.
Has anyone else observed this? I discarded the old links too quickly and now I don't know if they would be any different, but it's an expensive question to answer since the OEM links cost $100 per side. I'm not even sure if I'm supposed to do something different to "fill the gap" between the ball joints and the metal aperture they pass through...
Any experience or thoughts along these lines? Has anyone else had good luck with any brand of aftermarket links?
Thanks,
Andy
Last edited by andyman32; 10-20-11 at 11:15 AM.
10-20-11, 12:02 PM
#2
If you tightened them then they aren't moving. It's something else. Have you looked at the bushings and bushing holders?
Have you gone back to double check it was the stabilizer and not something else? Have you gone back and retorqued everything in the sub-frame area?
Have you gone back to double check it was the stabilizer and not something else? Have you gone back and retorqued everything in the sub-frame area?
10-20-11, 01:29 PM
#3
Rookie
Thread Starter
Yeah, it's definitely the stabilizer bar links. I've reproduced the sound by hand. I've also eliminated it completely by disconnecting the links and taking the car for a drive. I had thought it could be any number of things.
If you think about it, sandwiching the sway bar or the lower control arm between the ball joint and the nut might hold tight for a while but if there's play because the neck of the ball joint is smaller than the hole, it's GOING to work itself loose. The force of the sway bar acts perpendicular to the plane of the ball joint & nut.
On other cars, sway bar links tend to fit snugly into the aperture in the end of the sway bar and the control arm. Not so here. I'm wondering if it's just some spec that's off for aftermarket options - the latest set I put on had M10x1.25 threading. I think M12 would actually fit perfectly snug into the mounting hole in the control arm and the sway bar. That's the difference I'm looking for...
If you think about it, sandwiching the sway bar or the lower control arm between the ball joint and the nut might hold tight for a while but if there's play because the neck of the ball joint is smaller than the hole, it's GOING to work itself loose. The force of the sway bar acts perpendicular to the plane of the ball joint & nut.
On other cars, sway bar links tend to fit snugly into the aperture in the end of the sway bar and the control arm. Not so here. I'm wondering if it's just some spec that's off for aftermarket options - the latest set I put on had M10x1.25 threading. I think M12 would actually fit perfectly snug into the mounting hole in the control arm and the sway bar. That's the difference I'm looking for...
10-20-11, 02:34 PM
#4
Well actually most connections are friction connections meaning that there is play in the hole. The friction is what keeps it from moving.
Maybe the threads arn't deep enough or somethink like that. Have you tryied adding a washer to the front and back side of the bolts?
Maybe the threads arn't deep enough or somethink like that. Have you tryied adding a washer to the front and back side of the bolts?
10-21-11, 04:11 AM
#6
Rookie
Thread Starter
McPierson - yes, that's what I've been working on, the premise that it's a friction joint. But that's what just isn't working. I torque it down big-time, and the suspension runs BEAUTIFULLY for a few drive cycles, but the nut doesn't stay tight enough to keep that amount of friction applied after 3 or 4 (ish) drive cycles. I'm intensely curious as to whether the OEM ball joints have M12 'bolts', necks, whatever... that would be a perfect snug fit from what I could tell. But it would be a little weird that I bought two different sets from two different manufacturers and they were both wrong...
The parts I've thrown at it (this problem anyway) are really just the struts, but not the strut rods. Strut rods / bushings were recommended here and I was about to click "order" when I decided to do a little further experimentation. That's when I removed the links and strung up the sway bar with bungee cords and found that the drive was perfectly quiet over all kinds of broken pavement - the exact same pavement that reliably reproduces the clunk. It's definitely caused by the play between the ball joint necks and the apertures in the sway bar and the lower control arm.
Oh, and, the car has 73k miles on it and the strut rods have already been replaced once, by the PO. They're Lexus parts and still have the OEM replacement part stickers on them.
Very simple problem... very simple solution... IF (and only if) I can find a set of links with fatter necks. Maybe it's just a '99-'00 thing? Prior years fit an M10 perfectly?
I've even been thinking of some way I could fashion a metal sleeve or bushing to help fill the gap... that's all I really need to do to make this problem go away. But nothing comes to mind yet.
The parts I've thrown at it (this problem anyway) are really just the struts, but not the strut rods. Strut rods / bushings were recommended here and I was about to click "order" when I decided to do a little further experimentation. That's when I removed the links and strung up the sway bar with bungee cords and found that the drive was perfectly quiet over all kinds of broken pavement - the exact same pavement that reliably reproduces the clunk. It's definitely caused by the play between the ball joint necks and the apertures in the sway bar and the lower control arm.
Oh, and, the car has 73k miles on it and the strut rods have already been replaced once, by the PO. They're Lexus parts and still have the OEM replacement part stickers on them.
Very simple problem... very simple solution... IF (and only if) I can find a set of links with fatter necks. Maybe it's just a '99-'00 thing? Prior years fit an M10 perfectly?
I've even been thinking of some way I could fashion a metal sleeve or bushing to help fill the gap... that's all I really need to do to make this problem go away. But nothing comes to mind yet.
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10-21-11, 08:31 AM
#8
Pole Position
I've tried cranking down the stupid nuts with a 1,000 lb-ft air wrench, a breaker bar with a pipe, I've put on new grade 8 locknuts, heavy locking washers, AND slathered it with red loktite, and it still just won't stay tight enough to clamp down the ball joint sufficiently to prevent play after a few drive cycles.
that's way too much force. I've never changed mine but is there supposed to be a cotter pin that goes through the link bolt to stop the nut from turning loose? It doesn't say anything in my 93 manual except "install stabilizer bar links, L and R are different shapes".
12-03-11, 04:03 PM
#9
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Thread Starter
Greetings all. I just wanted to follow up here. I just finished a long day installing new stabilizer bar bushings, new strut mounts, and new strut bar bushings. Glad to say, my clunk is gone. The suspension & steering aren't PERFECT but the clunk I've been hunting for a full year now is no more.
A few observations for the sake of posterity:
- Since I replaced all three bushings on both sides at the same time, I don't know which one was "it". Obviously we'd tend to suspect the strut bar bushings, but the old ones looked almost as new (other than some road dust on them). Also, worth noting that the strut bars have already been replaced once already in the car's short (73k mile) life. So the new ones can't be too terribly worn anyway.
- All three things looked virtually as-new when compared to the new rubber. Nothing was cracked, nothing was visually compressed or distorted due to age. Everything fit snugly. Nothing wiggled excessively when force was applied with a lever. I've had a similar experience with transmission mounts - the rubber LOOKED perfect but it turns out that it was seriously compressed. When held up beside the new one, the new one stood almost an inch taller. Unfortunately there was no such thing in the Lexus, no "smoking gun". All of the old bits looked A-OK.
- Pressing out the old strut bar bushing was a real bear. I have a small 12-ton shop press and it was really pretty much at its limit. I had to seriously give it the beans to get the old bushing sleeve to start to move and both did so with a huge CRACK that sounded like a gunshot. Things would have been a bit easier with a 20-ton (or larger) press. So... for those who are only going for bushings, and not the strut bar assembly, be forewarned! I'll be a monkey's uncle if you could get it out with less than a 12-ton shop press...
- Obviously, the clunk wasn't due to the play in the stabilizer bar links. There was also some play in the strut bushing through-bolts (at the bottom). I bought some G8 bolts, washers and nuts that were just a smidgen fatter - something like 0.9mm larger diameter - and they fit very snugly. Still no dice.
So.... Bob's your uncle. It rides like a normal car again! Now I'm having a stiff drink, taking ibuprofen and going to bed.
A few observations for the sake of posterity:
- Since I replaced all three bushings on both sides at the same time, I don't know which one was "it". Obviously we'd tend to suspect the strut bar bushings, but the old ones looked almost as new (other than some road dust on them). Also, worth noting that the strut bars have already been replaced once already in the car's short (73k mile) life. So the new ones can't be too terribly worn anyway.
- All three things looked virtually as-new when compared to the new rubber. Nothing was cracked, nothing was visually compressed or distorted due to age. Everything fit snugly. Nothing wiggled excessively when force was applied with a lever. I've had a similar experience with transmission mounts - the rubber LOOKED perfect but it turns out that it was seriously compressed. When held up beside the new one, the new one stood almost an inch taller. Unfortunately there was no such thing in the Lexus, no "smoking gun". All of the old bits looked A-OK.
- Pressing out the old strut bar bushing was a real bear. I have a small 12-ton shop press and it was really pretty much at its limit. I had to seriously give it the beans to get the old bushing sleeve to start to move and both did so with a huge CRACK that sounded like a gunshot. Things would have been a bit easier with a 20-ton (or larger) press. So... for those who are only going for bushings, and not the strut bar assembly, be forewarned! I'll be a monkey's uncle if you could get it out with less than a 12-ton shop press...
- Obviously, the clunk wasn't due to the play in the stabilizer bar links. There was also some play in the strut bushing through-bolts (at the bottom). I bought some G8 bolts, washers and nuts that were just a smidgen fatter - something like 0.9mm larger diameter - and they fit very snugly. Still no dice.
So.... Bob's your uncle. It rides like a normal car again! Now I'm having a stiff drink, taking ibuprofen and going to bed.
Last edited by andyman32; 12-04-11 at 05:18 AM.
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