Hydraulic Release Bearing Install.

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benski105
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Location: New Zealand

Hydraulic Release Bearing Install.

Post by benski105 » Sat Mar 10, 2012 10:55 pm

so at the request of kevin, ill try and document how i went about installing a hydraulic release bearing and 7.25" twin plate clutch.
one of the biggest problems with using a strengthened pressure plate or racing clutch is that the release fork is often not strong enough to cope with the extra force which results in the fork flexing and often cracking or breaking. i have seen and heard of a lot of people who run into these issues and a hydraulic release bearing is the most reliable answer.

it will be a bit of a work in progress post, but ill start the ball rolling with a bit of a description with pics as i can take them.

i would consider this sort of install should come at the same time as a clutch upgrade or at least after the type of clutch has been decided!
i have used quartermaster clutches for quite some time now and have found them to be not only effective but very reliable. i have also supplied a few to other racers who have had equally good results. A considerable amount of my race parts come from the great global race-shop, Ebay. good quality second hand bits taken from top NASCAR teams can often be converted into most other cars with a small amount of thinking and of course a bit of work.

i started off by buying a good clutch off Ebay. if you choose to continue with the std setup then the set up is made much easier and cheaper.
the next step is to have a flywheel made to fit the knew clutch. i use a local machinist here in NZ who is known for his accuracy and ability to make beautiful race parts at a fair price.
once this is complete the flywheel/clutch assembly can be mounted in the clutch housing and work can begin fitting the release bearing.

As a side note, if you do go down the path of using a quartermaster or similar clutch, be aware that it may be near impossible to find clutch plates with the correct spline. my solution was to use the centre splines from some old 116 clutch plates, turned down and fitted/welded into the centre of a pair of quartermaster clutch centres. once done these centres can be re riveted onto new plates as needed - any good clutch specialist should be able to do this work for you!
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this is the clutch and flywheel assembly installed in the clutch housing. once this is done the release bearing install height can be worked out and the adapter made.

one of the problems with fitting a hydraulic release bearing into a 116 is the bell-housing area is small and compact. i did a lot of looking around and measuring!
the best i found, again this being a cheap Ebay score, was a Tilton 1500 series release bearing part # 61-1512.
the great thing with the release bearing is that, unlike some others, its self adjusting, so the initial setup is made that much easier as install heights don't have to be spot on!
if you are still going to use a std clutch, it would be worth checking to see if these aftermarket race-spec parts effectively operate on the std setup. alternatively quartermaster make some quite nice units that may be much better for this purpose.
there wasn't enough space to mount it with the bleed hole at the very top but i was able to fit it in by canting it to one side and removing one of the mounting legs.
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this shows the installed bearing complete with feed line from the exterior of the box. the bleed line runs out the top as shown on the pic below.
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the bleed line then is run via braided hose to an easy to reach place with a bleed nipple on the end.
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for mounting, i turned up a piece of steel that bolts to where the original release bearing tube attaches. i drilled out the 3 mounting holes and recessed them so the release bearing could sit flush. the front edge of the mounting bracket needs to have a spigot on the end the same diameter of the back of the release bearing so as to accurately locate it in the centre of the clutch. i then welded on 3 small legs, which were then drilled and tapped so the bearing could be fixed to the mounting flange.
depending on the flywheel and clutch used the thickness of the mounting flange could vary quite a lot. mine is approx 40-50mm long.

iv been unable to get the last few pics of my install but will do so in the next few days.
it may sound like a lot of work, but the whole thing didn't take much more than a good mornings work and the results a very satisfactory.

hopefully this will be at least a little bit helpful to fellow racers out there.
more pics to follow.

Ben
1962 Giulia Ti Race-car
1969 Giulia Super
1987 GTV6- new race project.
kevin
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Location: Esher, UK

Re: Hydraulic Release Bearing Install.

Post by kevin » Sun Mar 11, 2012 11:29 am

Ben , this is awesome thanks for sharing the hard thought out info. If you have a pick of plate under release bearing that would be great . Think I'm gonna change my forum name to sponge-kev :D as i have now got MD clutch housing made as well .
benski105
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Location: New Zealand

Re: Hydraulic Release Bearing Install.

Post by benski105 » Mon Mar 12, 2012 1:12 am

nothing wrong with soaking up other peoples solutions!!
here is the adapter, its nothing flash. its made of steel so it was easy to weld, but im thinking of going to ali as its much lighter. the steel version is quite heavy.
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also the front of the gearbox with the release bearing shaft removed.
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hope the setup works aswell for you as it has for me!!
1962 Giulia Ti Race-car
1969 Giulia Super
1987 GTV6- new race project.
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