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Lasse

Twin-plate clutch drag (Not related to hudraulic)

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On the OEM-AP/Lotus clutch pack the 'bearing-side/flywheel-side' marking offers a good 'offset' for the center parts of the plates -so it all goes easylie together. Maybe one or both of your plates are AP-parts, and luckily have the right diameter -but it could be exctracted from an different package ?! [maybe from an single plate system, in this case surprisingly with the right diameter and spline - as there is a lot available in this huge variations for AP-clutches..].

One thing is for sure -every AP plate-package I have seen in all those years was fitted with differend material looks and type of 'cutting' on the friction surface. Only the AP-'Renault spline' center was reused every time. So it just depends on what you get as replacement. Mention that the plates are stiff, without the usual springs and dampers as on every family-car. So the type [organic/semi organic] or race/sintered-metal for the plate is an importand point on acceleration feeling and type of engagement.

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Now I have also found out that the intermediate pressure plate (the one between the two friction discs) have been replaced (old invoice from S J Sportscars).

We have done some testing on the clutch release function. The outer disc release well (opens until the spring clips stops further widening) but there seem to be problem with relese on the inner disc. Could this be caused by the blade springs mounted on the intermediate plate, whose function I would presume would be to push the whole moving pack away from the inner disc.

I would guess if these springs are not strong enough that the pack will not move as required, inhibiting the release of the inner disc. Is there any experience that anyone could share? :thumbsup:

Best Regards /L

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To the best of my recollection, the intermediate plate "floats" on three guide pins. These pins have threads on one side which attach to the carrier, and the other end is just a post with spring clips that hold the intermediate plate to the carrier. The inner plate (nearest the flywheel) is free, where the outer plate (closest to throwout bearing) is sandwiched in between the main pressure plate and intermediate pressure plate. When reassembling the clutch pack Lotus recommends replacement of these guide pins and spring clips. I inquired about getting a set from my supplier and was told that a) they didn't have them in stock, and b) they did not think that replacement was 100% required unless damage had occured. I got lucky and was able to reuse my pins and clips. I did however make sure to clean as much of the clutch assembly as possible using brake cleaner and clean paper towels to remove any old clutch dust and gunk that had built up over the years. Make sure that the intermediate plate slides freely on the carrier to ensure proper disengagement of the inner disk (do not lubricate, only clean!).

One other note, make sure that the spring clips that attach to the guide pins are reinstalled in the correct orientation as this too is very important!

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The function of the pins and spring clips are to regulate the gap around the outer disc so it doesn't expand too much (decreasing the gap around the inner friction disc with the potential making it not release).

The idea is that the clips, which can slide only in one direction on the pins, is that as the outer friction disc wears, the clips will move on the pins to maintain proper opening of the clutch around the outer disc. This is the reason why Lotus require (not recommend) the pins & clips to be replaced when the pack has been disassembled.

I don't know, but to me it seems impossible to remove the pins from the intermediate disc without destroying the clips (they have to be cut because they lock the pins and can not be withdrawn in the "wrong" direction).

They also need to be changed when friction discs are changed because the clips will produce "markings" in the pins so that they will not move correctly (rather in steps) on the pins the second time around which can cause the intermediate disc to move so it becomes not parallel. It is imperative that the intermediate disc is parallel with everything else. If not, drag may occur.

BR //L

Edited by Lasse

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Hiya

Ok here are photos of a brand new "just out of the bag" AP racing OEM clutch assembly

on the 2 friction plates, it is clearly marked which one goes where and what orientation they should be on the plate's steel surface parts, I haven't looked to see if this matches the drawing in the manual but as these things come clamped together I would trust AP to pack them correctly. This one also has paint on the sides to show correct placement of the 2 intermediate plates

post-1988-127277503674.jpg

post-1988-127277504982.jpg

post-1988-127277507909.jpg

post-1988-127277509151.jpg

post-1988-127277510209.jpg

post-1988-127277511334.jpg

post-1988-127277513948.jpg

post-1988-127277516138.jpg

post-1988-127277517086.jpg

-Marcus

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Fantastic! :cheers:

Very clear and nice pictures! I've checked with the depiction in the manual, and it looks right (obviously AP knows how to put the stuff together).

Really nice that you could make the effort! Thanks a million.

BR //L :question:

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one year or so ago there was a couple of pictures with the *flywheel-side* bearing-side* posted too.. :cheers:

Sadly the forum does not have an 'library' section for this kind of stuff . .. this could make live more easy for other guys who will ask in future.

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Lasse,

Did you manage to resolve this problem in the end? I seem to be suffering a similar problem with clutch drag and it is sometimes impossible to find any gear with the engine running. Once turned off, I can get any gear without any issues. Just wondering how your story ended!

Thanks,

Steve.

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And.........replace the gearbox linkage UJ's, and the Master unit + new cables under the gearlever.

Sorted mine out andgearchange now is perfect

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Irrespective of how it might look, it could also be attibutable to the flywheel. I fitted new clutch plates (that I bought from Mike Sekinger) to overcome drag - but still had drag. I then fitted a complete new clutch assembly, still drag. In the end I gave up and took my car to Peter Smith. They opined that the flywheel needed replacement (in spite of no surface damage). Duly fitted: problem solved.

Also, the red spring clips (in the photos above in the thread) are simply to keep things together in transit.

It has been known for some people to try and retain them on the fitted clutch . . . That can produce a nice tinkling sound as said clips are flung off and then drop to the bottom of the bell-housing . . .

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..It has been known for some people to try and retain them on the fitted clutch . . . .

:smoke:

-that's a joke ..is it ?

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even if I repeat myself ..if there is a problem with a sticky/dry pilot bearing in the flywheel (this supports the clutch shaft!) -it will cause a steady spin on the clutch shaft as soon as the engine is running , even with clutch in 'open' position ..so as soon as someone is there to grease the splines and/or replace the clutch plates he should also inspect it for condition (something every serious mechanic would do so ..)

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I had this same problem with my 98.

I got new clutch discs from JAE, replaced the pilot bearing, and greased the splines on install... and no more clutch drag.

I have run into this problem on other multi disc clutches in the past.. and it has actually been the friction material separating from the clutch disc causing it to drag.

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