Noise in rear suspension-- hoping this is my last post on this

[AA-ron]

Hello Everyone,
I'm sorry to keep on this boring topic, but I've been plagued with this "thunking" sound in my rear suspension (IRS). I've spent hours and hours on this and have FINALLY nailed it down. It's actually not a thunking sound like I originally thought, its a dry rubber sound against metal, so its almost a bit of a "squeak-thunk"... ha, sorry about that description. So to narrow it down I built this lever and fulcrum arrangement to cycle the right rear suspension. With the wheel off, I can raise and lower the suspension and was able to find that it's the front bushings on the upper control arm on the passenger side. With my neighbor moving the lever, I crawled under the car and finally found this to be the source of the sound.
First step was to re-grease the fitting, pumping in so much grease as to make a complete mess. But I wanted to be sure it was getting everywhere. This had no effect on the sound. So I removed the control arm, cleaned all the joints, greased all the contacting areas and reassembled the arm. This completely got rid of the sound, which I then verified with a drive around town. NO NOISE for the first time in a month!

But then it came back after about 15 minutes of driving!

So here I am again with the exact same bushing squeak-thunk sound. I've checked and rechecked my torque settings, I'm seeing grease squeeze out where it should be, everything seems ok-- but obviously it's not.
Any suggestions? I'm loosing my head over this one as it's a very loud noise which can be heard by those I'm driving by. Are there better bushings than the ones supplied by FF5? Why is it only this one bushing that's causing the problem I wonder.
Any advice would be more than appreciated!!

Thanks

[Mastertech5]

Get upper control arms that use heim joints or R joints. They are also usually adjustable.

[weendoggy]

Get upper control arms that use heim joints or R joints. They are also usually adjustable.

Yeah, you want to hear clunking, get those!

[F500guy]

I saw a recommendation to cut slots on the ends of the bushings to better lube the ends of the bushing, Maybe that would help. I did not do that as my suspension was assembled before I saw that tip. Make sure you have good lube on the sway bar bushings as well.

[Nigel Allen]

I had a similar problem with squeaks, clunks and metallic clicks from the rear that seem to resonate up through the roll bar. For a while I was convinced the roll bar was rubbing against the body where it passes through the fibre glass body. In the end it was traced to stiction of the rubber suspension bushes. My highly experienced mechanic buddy put the car up on his hoist and used some penetrating lubricating spray on each bushing to try and identify the offending item. We didn't even pull the bushings apart. Funnily enough, the issue went away and 3 years later has still not returned. Maybe it was experience, maybe he just has the Midas touch... Like your issue, the noise was very audible and embarrassing, not to mention frustrating.

Best of luck with it all,

Nige

[CraigS]

There have been several threads about the mount ears for the control arms being either too close or too far apart. Did you have that on your car? When you had the arm off and apart how is the length of the steel sleeve inside the rubber bushing compared to the bushing? Any chance it is short, so you tighten the bolt and the mount ears tighten against the bushing but the sleeve is not clamped tight? In case you don't realize it, the mount ears should clamp the steel sleeve tight, the bushing should be tight in and rotate w/ the control arm on the sleeve.

[AA-ron]

Well its nice to know I'm not alone on this. My ears were a bit tight on some of the openings. And was referenced above, I do believe the sleeve might be a little short as the bushing seems to compress when I torque everything to correct setting. A sleeve length was not something I had considered and now that I do, it makes perfect sense. That's an easy enough fix as I can make a new sleeve that is just a bit longer. Luckily we have a nice rainy weekend coming up, so that will be a good project. I did cut additional channels in the bushings to make sure the grease had a nice path to where it needs to go, so that's covered. Thanks for the advice!