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Z320

hydraulic clutch release bearing (for TR4A-TR6)

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Hi Marco,

that’s a good idea.

Do you know if the seals in the new hydraulic clutch are compatible with mineral oil? I would expect so, but better to know for sure.

If not, the leaking oil may soften the seals, as there will always be some gear box oil (even mist) reach the seal faces.

Waldi

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Hi Waldi,

I do not care about that, the unit has a gaider and the situation is the same on the OVO.

Yersterday I spend some time to calculate if the OVO unit can be used with an adaptor with the Borg+Beck and original release bearing.

Yes, but air / play for abrasion is only 5 mm on a new clutch, the the clutch will not work anymore long before the friction plate will be worn.

We want to get 10 - 11 mm air, as on the original sleeve.

Other thoughts are how to make the construction more simple and easier and faster to bolt on the gearbox. Already got an idea....

Ciao, Marco

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Keep up with your nice engineering Marco.

it could well be that the old clutch design (B&B) required a longer travel because of the higher friction losses in shaft, levers etc.

Waldi

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Hi Waldi,

the Sachs clutch (not the friction plate) needs more travel, but is new about 2.5 mm shorter.

The difference is the release bearing! The sachs bearing is about 10 mm lower than the original one.

I'll make a photo later....

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Hi Waldi / all,

here comes the photo.

282724101_22Sachsandoriginalreleasebearing01.JPG.85f070643acba8604ce3745e12371c27.JPG

But perhaps the Sachs bearing also works with the B+B clutch...?

737294454_23Sachsandoriginalreleasebearing02.JPG.4a7edce7fc7fc6475956fd560125d2a0.JPG

This is how we bold the adaptor plate on 4 points on the gearbox, using the original threads,

the 4 threaded bolts are clued in the DIY connectors with Loctite strong, to have units - and also to get it oil sealed.

540010200_24newboltsandDIYconnectors.JPG.c1562b8137ce68219a2c6bb261f73a21.JPG

The "needed" (?) 2 upper ones are very specials made, because the countersunk screws need 6 mm material, but it is only 4 mm.

Perhaps we quit with the 2 upper bolts / connector on the next unit, this will saves a lot of effort.

764828465_25connectorsarespecial.JPG.0dcdeb59969c4cbc46fb831de343e3b5.JPG

Bolts with cupper washers and Loctite clued connectors in the gear box (imagine there would be one).

1981819988_26firstfit01.JPG.6ad330e9b27576b96657dd7c13c79844.JPG

Adaptor plate on the gerabox cover and 4 connectors.

1547907716_27firstfit02.JPG.c6836055a8c8fc1d2fd8db7f235c9ea7.JPG

To get the hydraulic unit on the plate, a little tricky:

had to lift the gaider and cut the plastic ring to bolt the unit on - and have to refit it.

On the work bench no problem, in the gearbox bell no joy.

385226496_28firstfit03.JPG.f306c5af116d14c4ef278d9897ad647e.JPG

What I realized first now: the hydraulik unit is turned clockwise - with the drills perfect fitted 45°/90°/180°!

948441013_29firstfit04.JPG.260430741d5add42848e472c9d0479d5.JPG

It's about 3.5°, we are shure this does not mather and perhaps helps us to bleed the system.

719625390_30firstfit05.JPG.a4703c6da810730a29f42d93b3267265.JPG

1637523629_31firstfit06.JPG.3c4d9a2601e330fc398294b73d416c55.JPG

We could set the squared drills and triangled drills on the adaptor plade with 3.5° difference -

and get in contact with the lower left bolt - or also quit with this and save some more efford.

244434889_32firstfit07.JPG.041b68c603d8d81a3fced864d3a9a2b9.JPG

Next is tho fit it all an empty gear box shell.

Ciao, Marco

Edited by Z320

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Hi,

today after office I made the first fit in the gear box bell.

Thought it could be a good idea to double check the remaining room with the Sachs hydraulic unit compressed:

about xy.0 mm we wanted and we got 1.5 mm less, enought to use the Sachs clutch until it is totally worn out.

361942403_33firstfitinthegearboxcompressed.JPG.8f84ce4cbf5ef1875fe2a666309f323c.JPG

Next check with die unit decompressed shows we have got enought way.

1977803809_34firstfitinthegearboxdecompressed.JPG.c274a6fee4b9bc29f4c84ec531bdc522.JPG 

Perhaps tomorrow I start with the pipework (hope my lovely wife has not too much work for me in the garden and on the house).

Ciao, Marco

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Very interesting to follow your way to get it work.

Unfortunately I lost the point how to fiddle the unit over the inshaft.

Last step was the little copper ring you fitted outside to get inside more space.

But I thought it was still not enough? What was the trick to get the extra space in the tube?

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Hi Andreas,

I reported some days ago with ths photo:

P1120084.JPG.647bf4c2b384a1b096fafd7ceb79b4f1.JPG

I put the unit body with the tube on the small adaptor, put it on the lathe and grinded the rim out with my Dremel.

The paper and tape keeps the dust away from the unit - so sorry me - there is nothing to see.

Ciao, Marco

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Today I had not much time to work on the project, so I only did the connectors for the pipe work.

The upper one is a standard (with some modifiations), too short for the bleed nipple, so I made a longer one from machinery steel.

1103319922_35connectorforthepipework.JPG.5a64db35608a04da44e389262b6eff72.JPG

Will got out with my wife today for some greek eating after a bussy day in the garden.

Kaló vrády, Marcos

Edited by Z320

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Hi,

by the way: we are 4 friends in the team, but "S" stays one some 100 km away from the others.

He made us 5 lovely brackets (stainless steel) to fix the connectors next to the gearbox where normally the slave cylinder is.

573204804_36bracketfront.JPG.e293ded232aefc075d4d9ebf8e520ba9.JPG

79698094_37bracketfrombehind.JPG.61e118b26054ce109cd01daf79b613e6.JPG

Next is to finish the pipes and test it.

Ciao/Cheers, Marco

 

Edited by Z320

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Here they are

855842157_38pipes1.JPG.4b2c90f991071afc012f951320d5a5a5.JPG

768906853_39pipes2.JPG.8f7fb538b85aca6160c58623dde02935.JPG

The clip left is to friend B, he is afraid of vibrations.

2037953660_40pipes3.JPG.24d093b459e6e72832d7ce7c4513ec62.JPG

41 pipes 4.JPG

1660153732_42pipes5.JPG.7b892bda937766b1783b69f40c80dc05.JPG

Next week is testing and put it on the TR6 (this gear box is an empty dummy).

Ciao / Cheers, Marco

Edited by Z320

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With a 0.7" master and 30 mm way we calculated about 9.92 mm way on the Sachs unit. 

1034268326_43calculation.JPG.834b4b860f4cfb9a65b3bde6b8cdbb4f.JPG

Yesterday I measured about 10 mm, I think that is OK....?

988917118_44testing.JPG.21fdca62f56e9ee7b0170be473a7798e.JPG

We calculate this is about 1 mm less than the original construction, the clutch needs about 6 mm to disconnect engine and gear box.

Total stroke of the Sachs unit is up to 21 mm, we have 10 mm from the master and 10 mm "air" for abrasion over the years.

Everything seems to be on a good way, but we have to use a 0.7" master (my plan is a 0.625") or limit the way of the original 0.75" master.

Edited by Z320

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Hi Marco, almost there and looking nice.

I would also opt for the smaller MC diameter, it will give a lighter pedal and not bend the diaphagm fingers unnessecary.

Does the bearing need to be in constant contact the Sachs clutch or will it have to retract a bit? 

Waldi

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Hi Waldi,

the 0.625" diameter could cause I have to push the pedal always through, this could be uncomfortable....

The release bearing of the Sachs hydraulic unit always pushes the bearing on the diagramm spring by a coil spring inside.

It would be possible to put the coil spring out so this will work the same as on the TR6.

Ciao, Marco

Edited by Z320

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Hi Marco,

a MC is easy enough, so not a big issue.

Make sure the releasebearing is rotating with the diaphragm to limit wear of the fingers of the diaphragm, i,e. It should not be stiff.

Curious how it will drive!

Waldi

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Hi,

we had a last test today with the new clutch on the TR6 engine and the empty gearbox with the Sachs hydraulic unit.

1473130834_45lasttest.JPG.df68d717ca0e7df144c284a78657035c.JPG

We slided the gearbox to the engine until the hydraulik unit got in contact with the diagram sping, we expacted about 10 mm gap - it was 12 mm.

This the hydraulik unit we will compressed when we bold the gear box on the engine.

1196281653_46gapengine-gearbox.thumb.JPG.d1dc05da67c69d31297515d5ab20296d.JPG

That's OK for the 0,625" master (moves the release bearing about 8 mm) and the 0,700" (moves it 10 mm), but not for the 0,750" master (11.7 mm way).

We got 14 mm with washers / shims.

2084042928_4714mmgapengine-gearbox.JPG.dd601711ad9b6c9c90a7321fa480cb50.JPG

Time for a summer brake, we all want to drive and not put the cars in pieces.

I will prepare the units when the weather is bad and we will fit the units on the cars next winter.

Ciao / Cheers, Marco

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Hi Marco,

nice results so far.

you wrote earlier that the Sachs hydraulic cil has 21 mm stroke. Currently you are at 14, so you could theoretically add 7 mm more shims, but off course it is better to not fully bottom the cil. So say add another 4 mm shims right?

It is good to have some reserve. There will also be some deflection from the steel plate and GB casing, probably less than 1mm maximum. And wear from the crank shaft thrust bearing, again, little, but all asks for more travel.

Enjoy the summer drives.

Waldi

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Hi friend W,

you fit well in our "clutch group".

The diaphragm spring is like a seesaw.

The end which is pressing the pressure plate on the friction plate moves "in" over the years because of the erosion of the friction plate,

while the end which you press with the release bearig moves "out" - but much more then the other end moves "in".

829106826_48gapofthereleasebearingsleeve.JPG.06638b461bb517f4a256ed1be1bf9e16.JPG

Therefor the release bearing needs a gap to the gear box cover, actually on my TR4A this is about 10 mm!!!

You need this to re-adjust the clutch from time to time, you can check this when you remove the push rod from the slave and move the leaver of the clutch shaft.

From a new clutch to a totally worn clutch we detemined about 6 mm difference for the B+B and about 10 mm (!) for the Sachs/Luk.

I want to use futher my old B+B with a 0,625 master, this is about 6 mm + 8 mm, so the 21 mm stroke of the hydraulic fits well.

Friend A wants to use his new Sachs with LuK friction plate and 0,75" master, that's 10 mm + 12 mm, that will not fit.

He thinks about this....

Ciao, Marco

 

 

 

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HI Marco,

                  it will be like waiting for a Christmas present for your next installment.

I will have to invent something over the Summer for you.

Roger 

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Hi Marco,

Danke:)

A day without a new insight or just a simple learning is a lost day...

I never gave much consideration to the exact working principle of a diaphragm clutch, but now learnt from your explanation the fingers come towards the GB side as the clutch plate wears! Thanks for that. It shows you should never “assume”.

Waldi

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Marco,

this is clearly not an off the shelf do-it-yourself project. Modifying the bearing, making an adapterplate, modifying the transmission cover. Most of us understand, but do not have the tools as you have. The alternative is buying such a set from our known TR Stores. However, those seem to be very expensive.

Nice work.....I am interested :-) But the earliest my transmission will be removed, will be (hopefully!!) next winter.

Jochem

PS Looking forward to your next project.

 

 

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Hi Roger, I'm very excited for your invention!

Hi Waldi and Jochem, thank you for your laud.

Edited by Z320

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Hi,

the first unit is in friend's "A" TR6 since yesterday and does a great job.

He is a brave guy without fear to test on his car what came out of my workshop!

So I started with the 3 units for friend B, C and me, they are already in parts.

2034780731_49moreunits.JPG.cdbfdadf5005dc4962a93c36a3f7e131.JPG

"A" does not want to quote the operating force because he uses a new clutch plate and cover but the original 0.75" master.

So I make a "clutch pedal meter" to determine the force on our TRs in their different conditions before and after.

My plan is to keep everything as it is, only swap over to the hydraulik unit (next winter).

Ciao / Cheers, Marco

 

 

Edited by Z320

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Very nice work!

I keep fingers crossed that it will work as good as it looks

but I am sure with all that measurement and calculation

it will be perfect!

 

Ours did not so. Pressure forces wil require the 0.625" master where we actually deal with 0.7"

and the bearing has a point where it gives a ugly howling when it meets the pressure plate.

Hopefully it will give that up after running in........

 

The feeling of the clutch engaging point is wonderfull, rest needs some more work.

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Hi Andreas,

I'm sorry to hear that from your project. You have to press the clutch pedal too strong or stronger as you expected?

Our release bearing is always running with the diaphragm spring, until now it is "inconspicuous and quiet",

the hydraulic works with the 0,75" master "smooth and good to operate".

That's what I've been told.

Ciao, Marco

  

Edited by Z320

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