tilton 3 plate clutch do not disengage in f3000 lola

[rodorico83]

Hello guys.

I have an issue with a new flywheel clutch installation im doing on my lola.
Ive trying to figure out what is the issue but im out of solutions ....
I hope you can give some guidance on things to check.
So i have a new 3 plate 5.5 clutch metallic installed with new step flywheel (0.1 inch).
clutch floater/preassure plates drection/positioning has been verified and is correct.
the 3 pressure plates slides easily in spline,
However i see that clutch fingers are slightly pointing inward which should not be. still dont know why.
master and slave cylinders are the lola original, which was for carbon AP clutch.
Based on Tilton doc a master travel of 0.8 inch should be enough to disengage, max travel of AP master cilinder is 30mm
I revised for leaks in master, lines and bearing and i could not see any leak around.
system has been bleed, and bearing has been stroked forward so it contacts with clutch fingers.

So when i press pedal, i feel some mm travel to build up pressure (~4mm). and then maybe another ~20mm travel. I can see that first floating plate disengages from pressure plate, and has slight free movement. but second and third does not.
I dont know how far bearing is pushing the fingers, but i would say that first plates clearance is not more than ~0.4 mm

Good is that at least i have access to see the bottom of the clutch and i can measure things.


So in general it take quite long travel to start seeing the first plate disengaging, like there is a leak, or like the bearing is far from springs. but i check both and seems to be fine.

Any suggestion fellas ???

I will try to post video

[J Leonard]

I don't remember the release fingers being inverted. Seems that would indicate the stack height being to thick.

[DaveW]

Not that I've ever had a multi-plate clutch, but as soon as one pressure plate or disk is disengaged, the pressure "should" be released on all PP's and disks, since there is only 1 spring and the components are in series.

So it appears to me there are 3, possibly separate, issues:
1. Spring is over-center w/o touching release brg (stack too thick or some other dimensional error?)
2. Too much travel to disengage 1st PP, and
3. something is flexing or binding, preventing the rest of the PP's/disks from being released once the 1st is released.

I suspect that if the unit is used, that the PP's have warped becoming cone-shaped from excess heat during prior usage. That could account for much of your problem. I had a similar issue on a single-plate Quartermaster clutch with the 2-piece PP/fulcrum where the PP had warped ~0.040" (~1.0 mm) off of flat causing trouble disengaging and a spongy feeling in the pedal. If you have 3 PP's, all with that issue, that could be your whole problem. Especially with a multi-disk clutch, EVERYTHING must be almost perfectly flat for it to work.

Issue 1: Measure everything again and resolve why spring is over center (could be the warpage adding thickness)
Issue 2: Make absolutely sure ALL air is bled out of hydraulic system.
Issue 3: Inspect and see where something could be binding (misalignment when tightened down, or ?)

[Bob L.]

Couple more thoughts....

1. Check full stackup....make sure you HAVE a 3 plate unit...
2. Check plates....I found when replacing a 2 plate floater (actually it was the pressure plate) that it had different thickness/dim. than single... how? Ordered new one, got here, installed, and it didn't work......checking found 2 different thicknesses...right part number ordered, wrong one sent.

Dave is right... one plate loose, all should be similar..

Have seen new ears bind on guides...(a new Tilton 3 plate)...had to dress those to make sure they moved freely. Nothing to do with the overtravel you've seen on fingers... think that leads to above...

Bob L.

[rodorico83]

Thanks for your feedback guys. I,ve been doing more check and i figured the following

I notice,
i could clearly feel with the pedal, that i can reach the hub of the first plate with the fingers on around 24mm travel of Master C.
adjusting the pedal stop just some mm before this fingers hitting hub feeling, i amuse with this will prevent the hub hitting the fingers when releasing but maybe is not enough i have to play with this, but if i reduce travel i got less clearance between plates .... so i have no much to play there.

I can feel about 0.05mm gap between first Friction P and PP and and first Floating P, 0 en second and third Friction P, if this 0.05 should be enough too have a full disengagement i dont know but i would say that it should be some more, 0.3 mm maybe (0.1 per plate)i dont know i will try to get this info from tilton.

I had the pedal press for some minutes and the gap remains so i guess circuit is ok in terms of leaks.


I notice that when gearbox torque bolted, starter can not turn clutch ring gear, but if i loose a bit gearbox bolts, just too make box loose, starter turns,as normal as without clutch, gearbox torque bolted without clutch also turn starter normal. So i imagine in the plate alignment process which i did with with typical tool but inserted into the end of the shaft so i can at least introduce 2 engine studs into gearbox and align as much as possible both components (otherwise it was always difficult with too much resistance to insert the last part of the shaft into pilot bearing). Note that shaft without clutch aligns perfectly with pilot bearing

Anyway i suppose that this resistance to turn will go away when clutch disengages for first time, but also it can be the one causing the no release of second and third plate....

tomorrow i will check how is the disengagement with the gearbox loose

In any case i think at least one cause of the issue is that fingers are pointing too inward, not giving enough clearance for travel. cause can be that any plate is bad, bend, dimensional incorrect as you suggested but i dont think so, the set is new it came with the Pressure plates as a kit. Friction plates i measure them and were correct.

I will check with tilton the clearance between fingers and plate hub
Anyway i will take measurements and send to tilton to be sure.

[DaveW]

Sounds like you are on the right track. It could be a slight misalignment of the disks with the input shaft that is making things bind and not operate as they should. I still wonder, though, about the spring fingers angle. They should be slanted toward the rear before disengagement starts. The clutch spring should never be slanted toward the engine more than a tiny amount even when the clutch is fully disengaged. Over-travel past flat has ruined (yielded/deformed) a lot of clutch springs.

[Purple Frog]

I'm with Dave.

I believe if one disc is loose, they all are loose. I'm guessing you didn't start it on the stands and see if it shifts.

But the alarm bells went off when you described the starter 'binding" issue. At this point in my mind its a two alarm fire. The fingers are too compressed, and the starter doesn't work when the unit is torqued properly.

Is input shaft getting too buried into the flywheel under correct torque?

[tlracer]

From a brief look at Tilton' s website, there appear to be two different stack configurations for the Sport 5.5" clutch discs:

https://tiltonracing.com/product/5-5...ch-disc-packs/

The 'back-to-back' arrangement appears to be different from the 'stacked' one, especially in the area of the centre/hub.

[rodorico83]

From a brief look at Tilton' s website, there appear to be two different stack configurations for the Sport 5.5" clutch discs:

https://tiltonracing.com/product/5-5...ch-disc-packs/

The 'back-to-back' arrangement appears to be different from the 'stacked' one, especially in the area of the centre/hub.

my configuraiton is back to back.

[rodorico83]

Sounds like you are on the right track. It could be a slight misalignment of the disks with the input shaft that is making things bind and not operate as they should. I still wonder, though, about the spring fingers angle. They should be slanted toward the rear before disengagement starts. The clutch spring should never be slanted toward the engine more than a tiny amount even when the clutch is fully disengaged. Over-travel past flat has ruined (yielded/deformed) a lot of clutch springs.

On doc is clearly stated that indeed fingers should point slightly towards gearbox when installed.
If the deform over travel pass flat is correct, then my springs are ruin, but this is second time i remove and inspect clutch and fingers were still looking good to me.

[rodorico83]

I'm with Dave.

I believe if one disc is loose, they all are loose. I'm guessing you didn't start it on the stands and see if it shifts.

But the alarm bells went off when you described the starter 'binding" issue. At this point in my mind its a two alarm fire. The fingers are too compressed, and the starter doesn't work when the unit is torqued properly.

Is input shaft getting too buried into the flywheel under correct torque?

well i verifed before installing clutch that gearbox shaft was engaging properly into pilot bearing, when both torque bolted, and starter was running fine in this situation, and there was no resistance at all when bolting to fully engage the shaft, with this i assumed that shaft length and alignment was correct.

About shifting, as that is also new installation, my plan was to setup clutch first

Note this is a complete new/different engine installation so it required new sandwich plate

[tlracer]

Okay, so you have verified the clutch is assembled correctly (discs in correct order and position, etc.) which is good to remove that question.

More questions:

a) You say you are using the original Lola release bearing, that is for an AP clutch. Are you certain that bearing works properly with the Tilton clutch, eg. does the bearing touch the Tilton fingers in the correct place?

b) You mention the travel on the master cylinder for the Tilton and AP, but the fluid displacement will depend on the piston diameter. Are you certain the slave cylinder is moving as far as it should to disengage the clutch?

c) Is the Tilton clutch the same depth ( = front of the basket to the fingers ) as the Lola's original AP clutch?

[rodorico83]

Okay, so you have verified the clutch is assembled correctly (discs in correct order and position, etc.) which is good to remove that question.

More questions:

a) You say you are using the original Lola release bearing, that is for an AP clutch. Are you certain that bearing works properly with the Tilton clutch, eg. does the bearing touch the Tilton fingers in the correct place?

b) You mention the travel on the master cylinder for the Tilton and AP, but the fluid displacement will depend on the piston diameter. Are you certain the slave cylinder is moving as far as it should to disengage the clutch?

c) Is the Tilton clutch the same depth ( = front of the basket to the fingers ) as the Lola's original AP clutch?

yes discs in correct order and position
yes bearing has been changed t0 38mm diameter as recomended by tilton.
i dont remember the figures of MC piston diameter but rememeber that they were quite close so i did not check much more about it, also the combination of master and slave cylinders remained, nothing changed there only the bearing. which should do about 10mm travel of slave.

[J Leonard]

Does the disc that mates with the flywheel surface sit flat on the contact area? Does the disc hub clear the pilot bearing area or disc to flywheel bolts. It's been a while but I think we had to use a thin hub center disc at the flywheel to put a 7 1/4 triple disc on a conversion engine.

[DaveW]

Does the disc that mates with the flywheel surface sit flat on the contact area? Does the disc hub clear the pilot bearing area or disc to flywheel bolts. It's been a while but I think we had to use a thin hub center disc at the flywheel to put a 7 1/4 triple disc on a conversion engine.

That makes good sense. If it were the case that would result in the spring being over-compressed (angled toward the engine near its center) due to the disk not seating flat on the flywheel. That could make that disk bind and would account for the resistance to rotation that Rodorico mentioned.

That would also occur if any of the disk center spline bosses were too thick to let the disks seat properly on the floating plates, not only the front one near the flywheel.

[tlracer]

So, either (a) the clutch assembly is incorrect, so it is physically not possible for the discs to open as they should or (b) the slave isn't giving the correct displacement under load.

If (a) - pull the clutch, check assembly order/orientation and look for witness marks indicating something is binding. Double check measurements;

If (b) - check displacement with no load and make sure internal seals, piston wear faces, etc. are all good. Under load, even minor wear to seals or piston surface could allow fluid past. If this happens only at the start of the travel, it wouldn't be evident with the pedal fully down but would limit the movement of the slave.

Having said all that, I don't see how (b) could cause the starter issue.

[rodorico83]

That makes good sense. If it were the case that would result in the spring being over-compressed (angled toward the engine near its center) due to the disk not seating flat on the flywheel. That could make that disk bind and would account for the resistance to rotation that Rodorico mentioned.

That would also occur if any of the disk center spline bosses were too thick to let the disks seat properly on the floating plates, not only the front one near the flywheel.

Indeed is good point. but i remember to check this also, and all clearance in that aspect were correct, the hubs between plates as long as you put in correct order they will not contact, and with flywheel is fine in this case the base of my flywheel is about 30mm from friction face

also i can confirm that all plates contact gap is zero at least in the point that i can measure.

[tlracer]

Master/slave cylinder setup

Tilton needs 0.8" master cylinder displacement to disengage the clutch ( = 20mm)

You get 4mm initial movement then 20mm. So that is barely the minimum Tilton require. In addition you do not know if the Tilton figure is based on the same diameter master cylinder as the AP one you have.

As the displacement is so marginal, it would take only a small difference in master cylinder diameter to mean you were not moving enough fluid volume to reduce the slave cylinder movement below the distance needed to disengage the clutch.

Clearly there is something very wrong somewhere. The only way you will find that is to take the setup apart then check, measure and verify all components.

[rodorico83]

So, either (a) the clutch assembly is incorrect, so it is physically not possible for the discs to open as they should or (b) the slave isn't giving the correct displacement under load.

If (a) - pull the clutch, check assembly order/orientation and look for witness marks indicating something is binding. Double check measurements;

If (b) - check displacement with no load and make sure internal seals, piston wear faces, etc. are all good. Under load, even minor wear to seals or piston surface could allow fluid past. If this happens only at the start of the travel, it wouldn't be evident with the pedal fully down but would limit the movement of the slave.

Having said all that, I don't see how (b) could cause the starter issue.

tomorrow i wil disassembly and measure thickness of plates and cross check with Tilton, but i would say is difficult that any plate is incorrect or damage as everything is new and im sure that friction disc thickness were correct, and thickness of pressure looks the same except the main one which is a bit thicker.
Also i think that travel is good as i can feel that i travel to the point that spring fingers touch plate hub i dont know this distance but i would guess that might be around 4mm as far as i can remember and that matches with the 20mm travel im doing of main cylinder.

my best candidate of problem is the clutch spring or is not good or i ruin it, which i dont think so but who knows. Anyway we will know soon the source of the issue as soon i check with these guys ...

So ive being doing some more check this afternoon and with an extra spacer between gearbox and engine of 1mm i could torque gearbox to engine and get back my starter working and rotating nicely fast. so then i checked if i was getting more plates disengagement, and indeed i manage to see the second plate moving freely as well, but the third is still hard to move but at least was able to move it.

So i really think that maybe gear shaft is too long, i recall to check this, maybe i did not fully torque i dont know.... also i remember that i had to remove some material from the gearbox clutch cover to prevent contact between clutch bolts and small are of gearbox...

its has been quite some months since i did all this check so my memory about it is no so fresh

[rodorico83]

Master/slave cylinder setup

Tilton needs 0.8" master cylinder displacement to disengage the clutch ( = 24mm)

You get 4mm initial movement then 20mm. So that is barely the minimum Tilton require. In addition you do not know if the Tilton figure is based on the same diameter master cylinder as the AP one you have.

As the displacement is so marginal, it would take only a small difference in master cylinder diameter to mean you were not moving enough fluid volume to reduce the slave cylinder movement below the distance needed to disengage the clutch.

Clearly there is something very wrong somewhere. The only way you will find that is to take the setup apart then check, measure and verify all components.

0.8 is 20mm
barely the minimun not i think is the normal travel to get full disengagement.
and if i remember correctly what would be even more interesting is that with 6mm of spring movement you will disengage, which i guess that should match the 20mm on master. thats why im eager to check distance between finger and hub on my setup so i know how much fingers are traveling

remember that all these figures are for tilton components.
to be more precise on my setup i do 20mm travel in total on master cylinder and max travel for this cylinder is 30mm

This will be the second time i take apart components, dont think i did not do it already !!
thats why i think components and clearances are correct.

[tlracer]

You will see I had already corrected the typing error of 20mm...

It doesn't matter what the master cylinder maximum travel is, if you are getting only 20mm then you are very close to the Tilton figure. So any small differences can reduce the slave movement below the minimum.

[DaveW]

Rodorico,

You still need to address the fact that the spring is in the compressed position before being pressed by the TO bearing. So something in or contacting the stack is too thick, pushing on the spring OD and causing that initial compression. The input shaft could not cause that even if it was too long.

IMO, there are several things that could do that and they are:
o disk friction surfaces too thick (not likely)
o disk splined hub(s) too thick
o floating plates too thick
o PP too thick
o clutch housing too shallow
o FW friction surface too tall
o FW nut too tall
o and anything else that we so far have not thought of

[scorp997]

I saw in an earlier post that you are using the “back to back” friction plate assembly. Do you physically have enough space in the flywheel recessed area for the flywheel bolts and the inside friction disc hub? You may need to use the “stacked” plate assembly with your car..

or or one or more friction plates are reversed in the assembly causing the binding

[tlracer]

@rodorico83 - is your starter ring gear bolted onto the face of the clutch basket?

[rodorico83]

I saw in an earlier post that you are using the “back to back” friction plate assembly. Do you physically have enough space in the flywheel recessed area for the flywheel bolts and the inside friction disc hub? You may need to use the “stacked” plate assembly with your car..

or or one or more friction plates are reversed in the assembly causing the binding

There is plenty of clearance between flywheel bolts and disc hub, as i comented flywheel friction face is around 30mm far from where flywheel bolts seats.
plates are in correct order, and is clearly visible that there is clearance between disc hubs...
im 90% sure that this is not a binding issue.

[rodorico83]

@rodorico83 - is your starter ring gear bolted onto the face of the clutch basket?

yes you can see it in the pic i posted before

[rodorico83]

Rodorico,

You still need to address the fact that the spring is in the compressed position before being pressed by the TO bearing. So something in or contacting the stack is too thick, pushing on the spring OD and causing that initial compression. The input shaft could not cause that even if it was too long.

IMO, there are several things that could do that and they are:
o disk friction surfaces too thick (not likely)
o disk splined hub(s) too thick
o floating plates too thick
o PP too thick
o clutch housing too shallow
o FW friction surface too tall
o FW nut too tall
o and anything else that we so far have not thought of

indeed this is the most important thing to check. i would add to the list faulty spring...


Thank you guys for all your comments were really helpful
I will post cause of this issue as soon as i figure out with tilton support.

[DaveW]

indeed this is the most important thing to check. i would add to the list faulty spring...


Thank you guys for all your comments were really helpful
I will post cause of this issue as soon as i figure out with tilton support.

If the spring was faulty, I would suspect that what it would do is to reduce clamping pressure and cause slippage under high torque. It would not, IMO, sit there in the already engaged position with the tips pointed toward the engine. So I think the spring, itself, is not to blame for your issues.

However, having said that, it could possibly be compromised by over-flexing. But that would not be evident now unless its position UNLOADED had the tips toward the engine.

A basic thing about steel springs and steel in general:
Steel does not noticeably reduce in modulus (stiffness) when it yields ("plastic" deformation). Also, it does not "creep" (lose shape gradually under load) unless the stress/load is almost at the yield point. So any significant reduction in load capacity is due to a permanent plastic deformation due to yielding. Normal metal temporary deflections (deflections that go away when the load is removed) are defined as "elastic."

[J Leonard]

@rodorico83 - is your starter ring gear bolted onto the face of the clutch basket?

The drawing on the Tilton site for the Sport 5.5 states the ability for the ring gear to be bolted to the face. The set up is very interesting. We could use a few more photos of this car to admire the posters handiwork.

[tlracer]

The drawing on the Tilton site for the Sport 5.5 states the ability for the ring gear to be bolted to the face. The set up is very interesting. We could use a few more photos of this car to admire the posters handiwork.

Correct. I was checking it was the ring gear rather than, say, an reluctor ring or similar. From the one close-up picture it isn't easy to determine scale and detail (especially on a mobile phone screen!)

The OP had mentioned problems with the starter as well as clutch disengagement, so my thought was whether the high load on the starter had managed to deform the clutch basket, which could have been causing the disengagement issue.

That said, I am still leaning towards the orientation of the clutch discs - not least as the Tilton assembly instructions aren't very good in how that describe loading these correctly.

[rodorico83]

I took thickness measurement of every plate and matches with the specification, same for the flywheel step.
Tilton confirmed that those fingers are indeed too close to the hub. But said nothing about its orientation ...
The issue with the gearbox matching and starter not working, has been solved, problem was that pilot bearing was damage and some material was push by shaft blocking and preventing the shaft to move forward, not allowing me to fully torque.

[tlracer]

Did you check the thickness of the pressure plate?

13.51 - 13.59 (mm) according the Tilton assembly drawing:

https://tiltonracing.com/wp-content/...ort-5.5_19.pdf

If that was too thick it would cause the fingers to be pointing inwards and also affect the disengage clearance.

[rodorico83]

Did you check the thickness of the pressure plate?

13.51 - 13.59 (mm) according the Tilton assembly drawing:

https://tiltonracing.com/wp-content/...ort-5.5_19.pdf

If that was too thick it would cause the fingers to be pointing inwards and also affect the disengage clearance.

yes that one i checked and is correct.
i checked again and i see now that central friction disc (with hub B ) is around 3.1 mm thick. I guess issue is coming from there.
Ill wait confirmation from tilton but that extra 0.5 mm, i test installing clutch and giving that clearance between flywheel bolting face and clutch legs bottom surface, I i get nice outward pointing fingers and much higher clearance between fingers tips and dish hub...

[DaveW]

yes that one i checked and is correct.
i checked again and i see now that central friction disc (with hub B ) is around 3.1 mm thick. I guess issue is coming from there.
Ill wait confirmation from tilton but that extra 0.5 mm, i test installing clutch and giving that clearance between flywheel bolting face and clutch legs bottom surface, I i get nice outward pointing fingers and much higher clearance between fingers tips and disk hub...

If I remember correctly, new friction disks should be ~0.104" (~2.6 mm) thick. So, as you said, I think you have found the cause of the spring-compression issue.

[rodorico83]

If I remember correctly, new friction disks should be ~0.104" (~2.6 mm) thick. So, as you said, I think you have found the cause of the spring-compression issue.

confirmed they will send a replacement