This weekend I decided to swap out my sway bar bushings, as part of my continuing quest to vanquish my suspension clunking noises. Once you figure out how to do it, its pretty simple:

1. Remove the entire air intake/air cleaner box assembly. Unscrew clamp at throttle body, unplug MAF sensor, unplug breather tube. Then undo the bolt holding the air filter box to the car, and undo the tiny screw holding down the snorkel thing. Lift the whole thing out carefully.

2. (be sure the car has cooled down sufficiently before doing this) There will still be a big thick coolant hose in the way. Unscrew the clamp, and carefully pull off. Be sure to position something to catch the coolant that will spill out. Carefully pull the hose aside and secure it. I usually lodge it again the power steering reservoir.

3. Now if you look down you'll be able to see the sway bar bushing clamps. But there will still be aluminium bar blocking your access. Its secured by 2 simple bolts on each side. Undo the bolts on both sides and you can remove bar. You don't need to completely remove it from the car, I just sorta repositioned it so it wasn't in the way.

4. The bushings are held on by clamps on the left and right side. Those clamps are held on by two bolts. But they're at a slight angle, so you'll need a ratchet extension and a universal joint. Depending upon your dexterity, you may be able to fit your hands in there and remove them with a regular ratchet wrench. The driver side bolts will be pretty easy to get to, but access from above to the passenger side bolts is hampered by the coolant tank and various hoses, so your best bet is to either use the extension and universal joint from driver side, or reach all the way in there with your hand.

5. Once the bolts are removed, lift the clamps and remove the bushings. Slip the new ones on, and reverse the installation instructions.

All good, right?

Not for me. One bolt on the passenger side absolutely refuses to go back in. It will only screw in half way, and will not budge for any force on earth. I even tried using an impact wrench and it still refuses to go in all the way. Could the threads be wrecked? I don't know what else to try.

 

Could be but it sounds like you're hitting a stop. Did you confirm the 4 bolts are the same size? If so, do a quick swap of two to determine if one bolt or bolt hole is stripped. Best of luck.

 

All four bolts are the same, but no matter which bolt you put into that specific hole, it will not screw more than half way in.

 

is it possible that a lock nut, or some such thing, has SLID down behind your threaded insert? Can you stick a piece of wire in there, and feel anything move?

 

1st of all, thanks for trying this, I had planned to change the front sway bar bushes on mine but the workshop manual said we had to drop the front subframe to do it, so I never got round to it. As i'm planning to change the radiator, water pump & bottom crank pulley soon, i'll be able to get these bushes changed then.

As far as why the bolt doesn't go in, yes the thread could be damaged, or maybe something is in there which blocks the bolt from going through.

Can you get a borescope / endoscope and have a look in there? (I bought one for $80 off ebay, it's paid for itself ten times over already).

The othe thing would be to get under the car and have a look at the captive nut from underneath. When we were looking at mine, there were holes cut in the chassis so you could see the captive nuts when looking from underneath. Maybe you'll spot the problem from there?

 

I don't think so. I didn't notice any type of lock nut on the other bolts. They all came out and when back in very smoothly. But I'll try and have a look tonight.

As usual, the manual is having a laugh at our expense. Doesn't it also say that you need to remove the bumper in order to replace a headlight bulb? I was actually very surprised at how easy the process was once you've figured it out. If I had to do it again, it would probably take less than 30 minutes.

I'm planning to have another go at it tonight, so I'll report back tomorrow with the results. Thank you both for the suggestions.

 

Well, I dug around last night and couldn't find a satisfactory method of securing that bushing clamp, so instead of wasting more time trying to jury-rig it, I took it over to the guys at my local shop to have them do it right. Hopefully they'll be able to get the proper sized bolts in, clamp everything down tight, and with some luck, the knocking noises will be gone.

 

I guess we'd all be interested to know if they find a reason for the bolt not going in when you tried it.

 

UPDATE: I just got a call from my guys. They said that the threads had indeed been chewed up, so they fixed them up, installed new bolts, and everything's good. Unfortunately, I won't be able to pick up the car until tomorrow morning to see if the knocking is gone.

 

Good lesson here. Should almost never try to force a bolt in. You should always take a little more time to try and figure out why it's not going in smooth. I used to try to force thing together in my earlier years as a mechanic, but I have learned the hard way that a good mechanic doesn't force parts together but finesses them together. It may take more time to put things back together, but you end up with a lot less headaches.


PS. when I change my sway bar bushings the radiator was already out so it was very easy. I would recommend anyone changing your radiator to include sway bar bushings when the radiator is out. It about another $60-70 in parts but chances are they are worn or going to be worn out soon so why not change at the same time and be good for another 50K miles.

 

Point taken and understood. Luckily for me this time, they didn't charge me anything for their work, but I'll slip them an extra $50 next time I see them.

That being said, there is still a tiny bit of clunking noise...and its definitely only coming from that side. So I'm thinking two things: 1) maybe they didn't tighten the bolts all the way, fearing the thread would get wrecked again, or 2) the metal clamp itself perhaps stretched, allowing that end of the bar to move somewhat freely? (I don't know if that's even possible)

Its definitely a huge improvement, but considering that I've come so far in trying to defeat this noise, I can't just give up when there's just 5% of it left. I don't know if I should try tightening the bolts some more, or if I should remove them and try to wedge an extra sliver of rubber or something in there. All I know is I cannot allow this noise to beat me.

 

Try to tighten your upper control arm bolts, the ones that attach the arm to the body. I think you can get at both sides from the top of the engine bay. Make sure those are 110% tight. Did you also check the lower control arm bushings?

 

Yes, those were all checked by my mechanic and double-checked by me. There isn't a doubt in my mind that the sway bar bushings were the culprit.

I just took another quick glance and noticed that the new bolt they installed in the repaired hole is an 8.8 grade instead of 10.9 like the others. Also, its not a flange head bolt like the others. Could that be causing the remaining looseness?

I used the extension ratchet to try tightening, but they were already tight as can be, so that's not the issue.

 

"or if I should remove them and try to wedge an extra sliver of rubber or something in there"

I have done this myself in the past to pass an MOT (roadworthy) on a SAAB.

If the bush is not big enough tightening a U shaped bracket will not tighten the bush on

the bar.

Painted the rubber with oil to make it look new. LoL

 

What was the condition of the sway bar itself? Any rust or necking/thinning where the bush is located?

Just asking because when we changed the rear sway bar on my XJR, it was thinned out considerably where the bush was, and rusting. If it's thinned out then that could be a reason for being loose.

EDIT

About the bolt, would be nice if the correct grade was used, but as you know finding exact replacment bolts on cars is not easy, they always seem to be special somehow. If they didn't use a flange head bolt then I hope at least there is a washer under the head?

 

disconnect the sway bar from one of the lower control arms and grab it and pry it up and down and feel for looseness or clunking to check to make sure the bushings are not still causing the noise. You may have a tricky noise to find now and you'll have to do really thorough inspections of all the components. Too often I see people say they checked something and think its good, but did not do a complete proper inspection of the component. I've even done it myself, thought something looked OK and moved on looking at other problem areas and didn't find it until I went back and checked again.

 

Have you checked your sub frame mounting bolts and your motor mount bolts?

 

Update: ran a test today to confirm it is indeed the sway bar causing the knocking noise. I disconnected both side endlinks and drove around the block. Noise gone.

Before conducting the test, I also replaced the grade 8.8 bolt they put in with a 10.9 flange head. Noise continued. I tried adding extra slivers of rubber under the camps. Noise worsened. This morning when I disconnected the end links, I grabbed the end of the sway bar and tried to reproduce sound. There was no play whatsoever.

So we know for certain the bar is causing the noise. Now the question is why. New bushings, new end links. I can't understand what the problem is.

I also inspected the condition of the bar itself. It seemed to be fine.

 

You are getting warmer and nearly there!

Correct me if I am wrong but the sway bar is bolted to the sub frame and extends across the width of the car.

Just guessing but the bar must be touching the frame somewhere along it's length.

When the Jag is in motion the bar maybe flexes and touches metal.

Keep going we want a happy ending to this story!

 

UPDATE: when removing the end links, I noticed that the nuts holding the ball joint to the sway bar were not flanged like the original ones were (I recently replaced both end links). So I got a pair of washers to place between the nut and the sway bar.

First I connected just the driver side end link (the side which has not been making noise). Drove around the block. No noise whatsoever.

I come back and connect the passenger side end link. I tighten everything up as much as possible. I drive around the block. Still no noise! I drive down the crappiest road I can find. No noise. I try everything to generate the noise but it won't manifest itself. By this time I'm trying very hard not to get giddy and start dancing in the middle of the street, so I calmly drive home.

I'm not ready to claim victory yet. This has happened before. The noise will go away for a few days and then comes back with a vengeance. If it does, at least I now know that it's being caused by something around the passenger side of sway bar.

I want to truly thank everyone for their comments and suggestions. Ill be sure to update. Time for a 12 pack of Guinness.