Thread: 2.5 years and 4 clutches. Soon will need another. My Puma

Loading the clutch mechanism also loads up the thrust washers on the crank shaft.

If the engine has been sitting a while, the oil film has drained away and then the thrust washer would be working drier than if the clutch was left engaged until the engine built up oil pressure.

I vote for having the gear box in neutral and leave the clutch alone until the engine oil pressure is up.
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Valid point about the engine thrust bearings but we are talking clutch failure.
Having worked on cars earthmoving and agricultural machinery over50 years I can't recall ever replacing crank thrusts without needing to replace the other crank bearings and quite a few machines had over center clutches as well As for Cold Pressure

I have been leaving the clutch alone when switching on & off in the past week (in neutral), and there is a loud rattle when doing so.

If I depress the clutch pedal, there is no rattle.

It seems to me that the engine vibration definitely gets to the clutch plate even in neutral?

That vibration goes right through the gearbox also, not good for the bearings ect.

I wonder if your flywheel face is true?
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Originally Posted by wrinklearthur

I wonder if your flywheel face is true?
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Or if it a dual mass flywheel? Those thing arn't good for much.

Originally Posted by Naks

I have been leaving the clutch alone when switching on & off in the past week (in neutral), and there is a loud rattle when doing so.

If I depress the clutch pedal, there is no rattle.

It seems to me that the engine vibration definitely gets to the clutch plate even in neutral?

When your pedal is pressed in - the clutch friction plate is disconnected from the flywheel and the engine. What you describe is the classic PUMA clutch rotational damping spring wear. Once the springs wear then as you switch the engine off it will clunk clunk clunk for a short period.

If you want to hear something spectacular - try putting the transfer case in neutral and idling with the gearbox in 5th or 6th. This will also cause the clutch springs to rattle their nuts off.

The PUMA clutch can last for a very long time with these rattles OR it may fail tomorrow if a spring gets loose enough to fall out and jam the clutch.

I'd doubt starting with the clutch plate engaged puts any more strain on those clutch springs than normal driving does. Those springs are under full compression when you are applying full throttle. If the gearbox is in neutral and you start it - at most you putting the rotational momentum of the clutch friction plate and gearbox primary pinion on those springs, which really should be very tiny compared to flooring the throttle in any gear.

The noise you hear when starting a PUMA or stopping a PUMA in neutral without pushing the clutch pedal is the roll over momentum of the clutch plate keeping time with the rotational torque pulses of the engine - a diesel engine has regular power pulses, so when in neutral you get rotational acceleration and then decelaration pulses timed to the engine rotation - so those springs go into compression and then tension (by a very small amount) as the engine idles or stops. If there is any play in the springs then it rattles.

Originally Posted by Gerokent

Or if it a dual mass flywheel? Those thing arn't good for much.

Puma has a 'normal' flywheel, not a DMF.

Don't DMFs last longer?