Squeaks, Groans and Clunks

[aaronjb]

This is why you do a final bolt torque with the weight of the cars on the wheels

Which can be a royal pain in the arse to achieve! Final tightening torque on my daily is 85Nm + 180deg on the inboard end and 100Nm + 90deg on the outboard end.. getting that 180degrees & 90degrees, even with the benefit of a pit to stand in, was quite a challenge!

[Eggbert]

You may not have bushings on your Cobra (mine doesn't), but this post may interest you anyway as most cars do.

I've had a lot of squeaks and clunks form my rear suspension lately and it has taken a lot of time for me to resolve all the issues, so I thought I'd post about it here. I've never really thought much about suspension bushings before and didn't really know how they worked. Maybe you're in the same boat?

First I'll start with a short video about how they work. The inner sleeve can move in relation to the inner sleeve by flexing the rubber. However to much flex and the rubber can tear. This is why you do a final bolt torque with the weight of the cars on the wheels. (Video is slow starting and changing scenes)



Here is a picture of a rear suspension with bushings incorporated into the control arms. In my case there was a terrible shriek from the bushing end of control arm 9. Bolt 12 needed to be tightened, but I didn't know that so I replaced the whole control arm (both sides)



I still had noises but one that was quite loud was from old dried out sway bar bushing. As I didn't want to wait the 10+ days for replacements to arrive,  I lubricated the inside of the rubber bushings with silicone grease (don't use any type of petroleum grease as it can degrade the rubber over time).





The last noise was really difficult to find and cure. It was a squeak and clunk just as I was to take off and torque was applied to the wheels via the engine.

Turns out it was from a misshapen spring which must have been made during manufacturing and didn't manifest itself as a problem until 130K later.

The normal top coil is shown above the deformed one. Trimming the end along the green line fixed it so it wouldn't dig in and bind things up.



I replaced items 2 and 3 and problem went away.

Here's a couple of pics I found on the net and you can clearly see the end of the spring does not dig into the rubber:





There was some tearing of the rubber insulator of the top hat section