gearchange = knocking? (synergie TD)

[Harlequin]

heya all - been a while damn work


wonder if anyone ha any ideas - got a problem with the syn , when ever I change gear theres a knocking relative to roadspeed - touch the brakes though and it goes away? any idea`s?

[Harlequin]

after some investigation its definitely mechanicaly and brakeing doesn't stop it.

[RichardW]

Is is occuring all the time, or just after a gear change? Is is related to whether you re turning or not? Is it related to acceleration? Is it road speed related, and does it stay if you coast in neutral?

My candidates would be CV joint, wheel bearing or diff bearing.

[Harlequin]

when its rolling , both engine off and on and only (afaik) when clutching in to change gear , pretty road speed related - a case of clutch down and `clunk clunk clunk` which goes when clutch lifted.

I`ll try a neutral check and report back

[Peter.N.]

I would suspect a CV joint.

Peter

[Harlequin]

thinkinging you gents are spot on so ordered both sides for £104 delivered from J&R

[Harlequin]

so - new driveshafts in (both inner cv had play OS worse than NS) , gearbox drained and refilled properly - it takes 2 1/2 liters! all engine mounts checked (note - bottom one needs doing)

and she is still knocking - worse now drive shafts been changed.

it is 100% roadspeed related. , pushing clutch is an almighty banging - its even there in neutral now coasting along.


clutch? or something worse?

[qprdude]

Flywheel?

[Peter.N.]

Is it at constant road speed noise or does it vary according to what gear you are in?

[RichardW]

An odd one.... I'd have said it's got to be the clutch, missing a finger or two (but is it a pull clutch I wonder....??). However, this doesn't quite fit as it should be engine speed related, and it should do it even if the car is stationary. Unless something is breaking up in the gearbox that only makes a noise when the wheels are driving the box, rather than the othe way around. Either way, it sounds like it's box out time....

[Richard_C]

Yours sounds more serious than what I am about to describe but here goes.

About 6 years ago I had a local garage put new front tyres on. When the Synergie came back, it had a knocking related to road speed and changing a bit with the steering angle. I took it back.

They spent ages trying to find the problem, it got to be a challenge for the boss because he had never had one like it before. Eventually he decided that one of the splined ends of the driveshaft wasn't seated properly, it was a long time back and I don't recall exactly but I think it was inner end of near side shaft. He thought maybe it had slipped marginally when the suspension was hanging down when they did the tyre job.

A judicious 'adjustment' with a large hide mallet solved it and the problem never recurred, I still have the car.

As you have done both cv joints it shouldn't be that, and it wouldn't explain your clutch noises, but worth a close examination and a jiggle before you spend more money perhaps?

[Harlequin]

its definitely road speed related , louder when clutch is used , but still there in gear - and sadly , even coasting not in gear I can hear (I think) a rhythmic thump thump thump

but definatey road speed. related , and much worse when clutch used.

ordered a clutch kit - im hoping its not fly wheel or heaven forbid gearbox... but it doesn't `feel` like the box to me , its a rotating noise (yes I checked the brakes as well)

[Peter.N.]

Does it make the same noise with the clutch depressed as it does if you put it out of gear?

Peter

[RichardW]

Post up the VIN and I'll check with box is fitted.... Some of them appear to have ML boxes - these are fitted to 1.4 Saxos etc, and have a propensity for lunching the diff, which IIRC makes the sort of noise you are experiencing

[Harlequin]

VF7**************[VIN obfuscated, can be read by forum staff]

edit:

its far worse when its clutch `in`