Constant Velocity joints

[slow-lane-Matt]

How do you know when your CV joints need replacing/renovating ?

I get a sound like someone is bashing the rear side under the bus with a hammer, particularly at lower speeds (10Mph) and when decelerating - but it could
just be the engine noise drowns out the clanking at higher speeds...

Is there anything else it could be...?

The MOT gave advisory on rear wheel bearings - and there is a bit of play in the wheel, can wheel bearings "clank"...?

Is there a test for CV joints...?

Any advice much appreciated !

Matthew

 

[Trikky2]

Worn CV joints will often reveal themselves when turning at low speed in a tight circle (like in a car park) by clicking.

Check - From under the bus try twisting the driveshaft each way - there should be no discernible play.

Wheel bearing will not normally clunk. If they are worn they will drone as speed rises and will get louder in bends, for instance, if the drone gets louder on left hand bends then its the right side bearing.

Rear wheel bearings on buses have natural play when cold, otherwise they would seize up when hot. Normal free play is between one and two mm at the wheel rim.

 

[slow-lane-Matt]

Many Thanks Trikky2

Do you know what could "clank" in that general area (rear/side) - I'll try to get a recording of it over the weekend

 

[KateLovesPurple]

Many Thanks Trikky2

Do you know what could "clank" in that general area (rear/side) - I'll try to get a recording of it over the weekend

As Trikky says, twist the drive shafts whilst under your bus, there should be no discernable play, if they are knacked, you will feel (and hear) the clank.

 

[rickyrooo1]

mine knocked when i backed off my drive at slow speed as i have to turn as i back, when i took them apart it was just sludge and water inside, replaced and all good, rear wheel bearings do move a bit but shouldn't knock.

 

[slow-lane-Matt]

I've had a look and there is no discernible play rotationally - but there is a couple of mm play longitudinally on both sides - and the noise it makes against the gearbox is similar to what we've been hearing.

Looks like my weekend's sorted....

Many Thanks to eveyone

 

[aogrady]

I've had a look and there is no discernible play rotationally - but there is a couple of mm play longitudinally on both sides - and the noise it makes against the gearbox is similar to what we've been hearing.

Looks like my weekend's sorted....

Many Thanks to eveyone

Hi,

There should be some in and out movement, it needs this as the suspension moves up and down, AFAIK anyway. if you move the shaft left and right, maybe you could try and swop the complete shafts end over end to the other side, i have heard this can sometimes work if the cv's have worn, it's a bit redneck, but may help diagnose. When mine started clacking on turns from a junction, i just replace the entire halfshaft, brand new complete, saved a lot of messing about, it's a very dirty job fiting new cv joints! Maybe yours are just dry old grease, maybe from a split boot?

Cheers,

Alistair

 

[slow-lane-Matt]

Well, in the event any other newbie ever comes across this post looking for help with suspect CV joints - this is the clanking noise I got when driving slowly. The only thing to add to all the comments
above is that the drive shaft seemed pretty solid when shaken by hand when the wheels are on the ground - its only when jacked up the problem is easily reproduced.

Now off to buy an M8 spline bit!

{video/click}

 

[rickyrooo1]

they do move in and out mate, they have to so they dont break when the wheel travels up and down with the suspension, chances are they are worn or have no grease left in them, i recently replaced mine it's a messy job.

 

[Araon]

I'd hazard a guess that they are dry and in need of a good clean and grease as said the lateral movement is fine

 

[slow-lane-Matt]

Well, took the driveshaft off - and the problem was obvious - there is meant to be a circlip to hold the CV joint tight on the splines of the drive shaft. There was no circlip, so the CV joint rode up and down the drivedrive shaft, merrily clanging away at each corner !

Good news - cheap and easy to fix - and the CV joints, when clean and greased, what a great bit of engineering !