940 supension clunk

[lightyears]

Noticed this just recently, when reversing out of a tight space on full lock there is a very apparent clunk, almost feels like it is going over a drain cover or something, it passes as soon as i turn. The car squeals a bit on full lock going forwards but no clunkiness.. Any idea's?

[ThePurplePanther]

I have a similar problem so am intrigued to see what the collective forum brain can come up with.

Assuming mine is the same as yours it's almost like the wheel drags or skips slightly at extreme lock with as you say an audible clunk when you are moving at slow speed.

(I am suspecting worn ball joints - two new ones arrived today to be fitted soon. But plan on doing all the suspension 'consumables' - 20 yr old car and if it's not clealy new/swapped by me I always assume all the old bits are knackered. Bushes/droplinks etc... a bit of slop in any of them can add up, esp if it is at the end of a lever)

[lightyears]

My research indicates lower ball joints but its always worth throwing it out to the team to get some alternate opinions.

[ThePurplePanther]

Can you get it up in the air and see if there is any play in the wheel? (may need a short pry bar to lever the joint against the suspension)

Just thinking how my MOT guy checks stuff...

[plus nice to see a fellow Bob's Burger's fan!]

[lightyears]

unfortunately i haven't got ramp access but visual inspection this evening hints that it may be cooked. I'm thinking maybe doing the whole wheel arch with new bits as they are cheap and easily obtainable.

[ThePurplePanther]

Tis normally my approach to jobs like this.

Take it all apart, change all the bits - once - with good quality replacements and forget it for the rest of your ownership...

[Laird Scooby]

Wheel alignment - "they all do that sir!".

If the wheel alignment (aka "tracking") is slightly out it will give this effect. Sometimes even with the tracking spot-on it does it but usually only when reversing at full lock.

Having said that, check the "spaceship" bushes more correctly known as lower control arm to tie bar bushes, wear in these can cause the problem and also wheel alignment problems. Also as you rightly point out, the lower ball joints can also cause it but usually they cause "woolly" feeling steering before clunking like this and/or "skipping" on full lock.

If you're going to change the bottom ball joints yourself, you'll need one of these :

https://www.ebay.co.uk/itm/Commercia...oAAOSw-W5Uv8ua

Either that or remove the bolts that hold the ball joint to the strut, remove the control arm and take it somewhere they have a press - these aren't the average ball joints that pop out of their tapers relatively easily!

[lightyears]

im trying to picture where the spaceship bushes are in my mind. Don't suppose you have a diagram do you?

[Laird Scooby]

Originally Posted by lightyears

im trying to picture where the spaceship bushes are in my mind. Don't suppose you have a diagram do you?

Lifted from the Haynes Book of Fantasy :





Just to clarify something - i used the words "tie bar" in my post above, "radius rod" and "Radius Arm" can also apply to the same component.

In the first picture, the control arm (8) and the radius arm (9) have the spaceship bushes, one behind the control arm on the radius arm, the other in front of the control arm so two per side. The second photo shows a slightly different view and makes a useful point about retightening them after a period of time if they've been replaced as well as showing the basic shape of the bushes. They can be found on ebay relatively cheaply :

http://www.ebay.co.uk/itm/Genuine-FE...UAAOSw6B5Zcfoz



However it's probably more economical to buy a complete kit as it comes with the bolts, spacers and washers, one kit does one side so you'll need two kits :

https://www.ebay.co.uk/itm/VOLVO-740...YAAOSw1DtXEgOj

When changing them, it makes life easier to remove the bolt that holds the anti-roll bar drop link to the control arm - if you're renewing the drop links at the same time they will likely be off at this time anyway.

[mjk164]

When replacing the radius arm bushes (spaceship ones), you can use the original black rubber type and be prepared to do that again regularly as they don't last long. My advise would be to use polyurethane bushes such as available from Superflex. I put theses on my 1993 960 (with 380k on the clock) and they have been good for at least 100000 miles. They are stiffer than original but much better. The squeal you are hearing at full lock is coming from the power steering pump and it is designed to "by-pass" excessive fluid pressure when on full lock....quite normal.