Knocking clutch - XFlow

[TerryF]

When idling (1600 X Flow)there is a loud knocking from the clutch area, which is linked to engine speed. Depressing the clutch pedal stops the noise completely, as does putting the engine under load. There is no apparent effect on performace, but it sounds terrible when waiting at the lights! Any suggestions before I decide to strip the clutch?

 

TerryF

[Graham Sewell]

If the noise goes away when you press the clutch pedal, the normal cause would be the thrust bearing. However, you comment about it going away when the engine is under load would imply that is may not be the clutch but the input shaft to the gearbox having some play. This assumes that the noise returns when coasting in gear with the clutch pedal released.

 

I would suggest getting a professional ear involved with the diagnosis!

 

Low tech luddite - xflow and proud!

[Roger King]

It sounds like the normal noise that the gearbox makes at idle. In a production Ford you don't notice it because of all the sound insulation, but in a 7 it is very audible.

 

Best description would be 'clonking rattle'.

 

Of course, I can't be certain that all is OK, but it sounds like it is.

[TerryF]

Roger, Thanks for the response. There has always been a bit of a knock in the three years or so that I have had the car, but over the last two or three months it had become significantly louder and certainly doesn't sound 'normal'.

 

TerryF

[sjwb]

To be pedantic, knock isn't really what you should hear. The noise may better be described as a rattle. And that is what is happening; the backlash in the gear set (input shaft to cluster gear) is being excited by engine accels and decels. For that, read uneven or low idle speed. Pick the revs up a little and I am sure it will improve.

 

Steve B

[J.R.]

The above advice applies to ford 5 speed boxes, the 4 speed should not exhibit said noises when in good health, the 5 speed does

[JKJ]

Yeh, get exactly the same noise from my 1700 SS at idle with the clutch out. Noise goes when the clutch is depressed or the engine revs increase. Take it as being normal as it's done this from when I aquirred the car, 9000 miles, to present, 26000 miles.

[Roger King]

sjwb has reminded me of something. As he says, the slower the idle, the worse the noise gets as the effect of engine speed changes gets magnified. This can get even worse if the carbs are out of balance or have incorrect mixture settings, so it may be possible to reduce the noise by setting them up properly.

[New7er]

I have the same as did previous owner on 1700SSand the car now has 34000 miles up but it all works fine - famous last words! I've tried adjusting the clutch cable to no effect but, as suggested get the tick over up a tad, say 1000, and it seems to disappear. Don't worry if it is a light rattling noise only, almost shot big end sounding at its worst. anything more get it checked out.

[TerryF]

Thanks to everyone for the advice. I have upped the idle speed to around 1000 rpm, and the problem has all but disappeared. I certainly don't intend to look any deeper at this stage.

 

TerryF