cv joints

The message from "Kay" contains these words:

Eventually, yes. The joint tranmits all the power to the wheel and though it'll take a while, if it fails you'll be left with a sudden loss of power to /both/ wheels ('cos once one goes the differential will allow that shaft to spin at double speed and the other to do sod all). There's also the possibility that as it fails it will do other damage if the shaft starts flailing about, and it may interfere with the steering as it fails as well.

So, it may not be immediately urgent, but it /does/ need doing.

They can sometimes survive in this condition for quite a while but it is a very good idea to change them now before you get stranded (or worse!). Speak to Reco-Prop in Luton. They supply OEM quality at excellent prices.

JB

Hi Kay

I had what i thought was a duff CV joint that turned out to simply be a rusted spline on the end of the drive shaft.

I changed the joint anyway as well as the shaft as i didn't like the idea of that crap swimming in the grease.

It is a common problem i discovered and your car may be the subject of a free replacement, so check with uncle Henry before you whip out your wad and DIY!

Looks like I'll be getting it fixed then! One thing that puzzles me, looking at the photos of a cv joint in Haynes I can't see how they fail. The 'tripod' seems to be large enough in its housing that this won't allow the shaft to spin. The only bit to fail as far as I can see are the splines on the end of the shaft that the tripod slides onto - am I correct? If these wear the shaft would just judder and slip before actually spinning freely, again am I right in thinking this? So what exactly causes the clicking sound on full lock, the tripod or the splines, or something else entirely?

The message from "Kay" contains these words:

Something else entirely! There's a half a dozen balls in a cage which cunningly moves to half the angle the joint's bent to - and it's this bisecting of the angle which allows the joint to transmit power at a constant velocity instead of in jerks as you'd get with a simple universal joint. As the joint wears the balls get worn and smaller and also they make notches for themselves in the tracks in which they run. It's the balls snicking into these worn patches that makes the noise.

Take the balls out and the inner can easily turn inside the outers - and when the thing fails the balls do indeed fall out.

On the end of each tripod arm there's a ball. Either the ball wears smaller & wears a groove in the housing or the needle bearings the ball spins on on the tripod arm break up. Once it can't slide freely they wear & disintegrate such that the balls fall out.

We have a 1985 Volkswagen polo whose CV joints have been clicking on moderate lock for a number of years now. Initially (years ago) we did think about sorting them out then.. but decided to see how long it would last..

If you were to adopt a similar route (especially if the clicking is only very mild, or hasnt been occurring for long) then I dont see why your CV joint wouldnt last a similarly long time, provided that you do the following:

Examine the CV boot for splits, and renew with a proper one (not a split-and-glue-together one) Pack the joint out with a good amount of clean, cv-joint grease Avoid using full lock if possible If full lock must be used, do not be savage with the accelerator

If my 178000 mile mondeo had a cv joint problem now, i know that i, personally, wouldnt bother touching them as something else would probably fail before the CV joint gave up (following the above guidelines). If your mondeo is much newer, then this would naturally affect your decision, but seeing as the CV joints are less critical than, e.g. a broken head gasket, you should consider whether they are actually economical to repair

Ah, it all mkes sense now. Using the replies and looking again at the photos in Haynes I can see the bearing rollers.