Yes there is. Pull the arm, attach it to a vise, bolt the joint thread to a suitable extension for leverage, work it around with a pry bar and listen/feel for vertical and horizontal play. Use a stethoscope and a dial gauge if need be. If the ball joints are still ok but on their way out in the near future, there's no noticeable play but they move by hand with virtually no effort.

If the bushings are intact, which they aren't in a case like this, the pry bar test can be done without removing the arms. A fairly elementary check-up procedure, the annual MOT performs a similar test too.

My wife's RS6 is due for a bushing and ball joint upgrade shortly. The arms have 70k miles on them hence we use new replacements, pop the brand new rubber bushings out and replace them with PU. That's an ideal solution for maximum comfort, precision and longevity as the car just received a fresh Dahlbäck-built engine with turbos to match and a rebuilt, upgraded 5HP24, so it's turning out to be a keeper.

 

Hello @hq_
I understand this procedure 100%, that was my point, having done the same in the past, having the ball joint feel fine, as in no play, not easily moved, only to have the ball joint start to clunk some 5 to 7k miles down the road, so my opinion is to just change out the entire control arm, as in research the opinion is that the ball joints actually get more of workout compared to bushings.

Just my thoughts.

Johnny

 

That's the safest bet. Rubber bushings unfortunately have the same problem as shock absorbers, they deteriorate gradually and surprisingly rapidly. The bushings we took out when upgrading looked perfectly fine, no tears, cracking or even "scaly" surface anywhere, but they had worn soft enough to cause vibration at highway speeds. The ball joints were still snug so we pressed the PU bushings in and called it a day. With PU bushings the joints fail long before the bushings so now we know the culprit by deductive reasoning if/when slack, vibration or any vagueness manifests itself.

I really hate it when manufacturers integrate effectively non-replaceable parts into components but there's nothing you can do about it.

The Supersport models have reportedly "50% less compliant" bushings than base models and it's rumored that Speed models are somewhere in between. 80 shore PU should be a close match to what Supersport has from the factory, with a much longer real-world service life as a bonus. I went with 90 shore but I like my cars sharp and precise, with no undue floatiness whatsoever. It's still a bit of a comfy barge but the improvement in the steering feel and tracking was staggering.

 

I think there's an exception here, which is when some monkey doing an alignment or something re-tightened the bushing at full drop (instead of at ride height). That could destroy a bushing long before the ball joint was knackered.

 

Yes. Any competent mechanic can determine the condition of the ball joints using the standard method.

 

Randy,
That's my whole point, I have been around cars since I was born, and started working on them seriously around 13 - 14 years old, so that's 50 years working on them, I have done just as one would checking ball joints, but the last time a few years back, I did just as others, I replaced just the bushings, as the ball joints made no noise, had no play, and looked fine, boots in fine shape, ect, only to have the upper control arm ball joints start to make clunking in 5000 miles or so, and yes, I tightened all the arms in the proper loaded position, so it is my opinion to just replace the entire arm as new, as even if I got 15000 miles out of it, I am doing the job twice in a shorter time frame then as if all new was installed.

I should have been more detailed in my question, I meant, is the any more in-depth detailed method of measurement of ware, not just sound, feel, and movement, like putting the arm in a tool to measure the in and out movement of the ball in the socket, if such testing tool exists.

Again, just my opinion/thoughts.

Johnny

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Hi Johnny,

My guess is that a lot of it comes down to the weight of these cars (and the fact that some of it is cantilevered out over the front axle). In another car, if you got 30,000 miles between replacing the bushing and doing the ball-joint, you might be happy enough with not having replaced the whole arm. The fact that it's 15,000 on these cars is what puts the fine point on wondering about whether or not it's false economy.

For what it's worth, I had a habit of doing whole-arms on my Arnage, and will probably continue with that strategy on the Spur.

On the question of wear, I suspect you could measure how much the Belleville washer is flexing with a mic and a press. But that will only tell you how much additional axial wear it can compensate for; the washer doesn't help much with lateral wear. (I don't have a clue which is the dominant failure mode here.)

Cheers,
Jeff