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Self adjusting clutches

Started by johnnyroper, January 09, 2021, 06:35:57 PM

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Anyone had any experience with self adjusting clutches?
What a pain in the arse they are.

Replacing clutch/DMF and timing chain on my bmw which has a self adjusting luk clutch,the new one comes with a locking plate holding springs down that you remove when clutch is aligned and secured. Thatââ,¬â,,¢s not an issue however I had to remove it again due to other issues so had to reset the self adjuster. There is a special tool that you can buy to compress it and refit locking plate but I couldnââ,¬â,,¢t justify the expense for a 1 off job.

Had to get creative with the old release bearing and hydraulic press to get plate back on.
Whoever designs this stuff wants shooting,firstly putting timing chains behind flywheel so engine needs pulling out and then these stupid clutches!!

Rant over

Whoever designs timing gear with (presumably) endless timing chains requiring the gearbox and flywheel to come off to replace is either extremely confident in their design or they don't give a s@*t about the maintenance aspect as long as it lasts long enough to get the vehicle through the warranty period.

Not had the pleasure yet with one of those clutches you describe, if the clutch still needs aligning when fitting, what is the (supposed) engineering benefit to using the 'self adjusting' system over the conventional clutch type?
Always learning..... Often by mistakes!

Thatââ,¬â,,¢s just it the design has proved to be somewhat problematic, 3 chains,2 tensioners,4 guides and 3 sprockets need changing. On earlier engines the crank sprocket was a known weak point which meant crank also being replaced. Itââ,¬â,,¢s not so much the design thatââ,¬â,,¢s the issue itââ,¬â,,¢s the ridiculous bmw servicing schedule that causes the failures the 6 pots donââ,¬â,,¢t suffer the high failure rate as they hold about 3 extra litres of oil.
There was nothing actually wrong with mine no noise etc but as I was doing clutch and flywheel I thought itââ,¬â,,¢s foolish not to spend an extra Ã,£200 and do chain kit at same time.
On the 5 series it can be done in situ but I opted to remove engine and work on it in the garage instead of on my back on the drive.

From what I can gather the SAC type takes up slack when friction material wears to give a constant pedal feel. Non of this bite at top or bottom business that traditional clutches have.

This is a SAC type pressure plate, the adjusting part is the 3 spring loaded bits,hard to see exactly how it works but it appears as plate wears the pressure plate mating face is pushed out by the spring pressure when you release the clutch. When bolting up and removing the locking plate thatââ,¬â,,¢s certainly what appears to happen.

So the issue is that once you remove the clutch from the flywheel the spring force from the self adjuster pushes the pressure plate too far in the friction disc direction for you to be able to locate the clutch pressure plate on the flywheel dowels (assuming that it's got them) and get the bolts caught to pull it into place?
Always learning..... Often by mistakes!

To a certain extent yes but you can refit it without resetting but I suspect it causes premature clutch wear.  My original one had been off recently as seller changed just the primary chain,the clutch was mullared and didnââ,¬â,,¢t feel good. Not sure if you would be able to bolt up a new clutch that has more material on it,when removing the clutch as bolts are released you can see the adjuster pushing the meting face further out.

When refitting the new one pressure plate is bolted up but friction plate is still free to move until you release lock plate. You can then see the adjuster taking up the slack.