Hydraulic Release Bearing for the 914 Transmission, Push type clutches only Options

[tomeric914]

Been kicking around the idea of using a hydraulic release bearing (HRB) instead of a slave cylinder, stock fork and stock release bearing. You could argue that this route is more expensive, but it isn't that much more than a stock throwout bearing. Most modern stickshifts use a HRB. They're simpler, cut out a bunch of moving parts and generally give better feel.

Goal is for the adapter to bolt in with no modifications to the trans or bellhousing other than to remove the two 6mm studs that hold on the throwout bearing guide tube.

One fitting runs through one of the two inspection holes at the top for a bleeder fitting. The other will be a stainless braided line out the fork hole with a little bracket to hold it in place.

You'll also need to install a clutch master cylinder of your choosing up front.

If this interests you, I'll probably make a bunch of adapters and offer them up here. Let me know what you think. Could also be in kit form with everything needed. For now, here's a teaser shot of the mock-up.

[sixnotfour]

Is that a GT3 Cup release bearing ?? OOPS... Tilton

[rfinegan]

looks like a GREAT solution ...follow this one for sure

[tomeric914]

Is that a GT3 Cup release bearing ?? OOPS... Tilton

Yep, Tilton. They make the lowest profile HRB that fits.

I started another thread asking if anyone else had their engine out to see what other's depth to the clutch fingers from the engine case were. My concern is that I am only looking at my setup. If someone else is interested, they will need to verify their clutch setup depth.

[Ninja]

I fought that fight 10 years ago on a big block cobra replica posted on my website.

https://granburyautoac.com/big-block-cobra-...ets-new-clutch/

Not my writing on the website...

What that doesn't show is the fact that I had to remove and install the transmission 4 times before I got the "stack height" correct...

The published specs for the slave cylinder were ONLY a general guide. It didn't work like it was supposed to.

It required shimming the transmission back from the engine (fabrication type mod) before I both had enough free-play and the pressure plate fingers were not over-articulated.

At that point it ALSO required modifying the transmission tunnel for shifter clearance...

Clutch Master cylinder diameter and stroke were EXTREMELY important. It required a master change as well.

A job that should have taken 4 hours took 20! (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif)

This was on an engine/trans combo that was "normal" for the hot-rod crowd AND came with an earlier version of the part already installed which turned out to be the main reason for the previously failed clutch.
The first shop botched the initial installation when the car was built.

Both new and old was Tilton. The new slave had multiple "length adjustment" rings which HELPED!

I love the IDEA of internal slave, when they are designed properly, they work fine.

Never again will I try to use an internal retrofit slave kit IF usable external versions are available and I have room for them!

Maybe the new stuff (10 years have passed) is better...

Good luck!
I will be watching your progress. (IMG:style_emoticons/default/ninja.gif)

[Cupomeat]

I'm interested in this solution. Sorry, I don't have access to get you dimensions.

Good luck!


Eric

[tomeric914]

I should have 5 of the adapters complete in the next couple of weeks.

If anyone is really interested and has their engine out. Please take a couple of dimensions as outlined in the link below and let me know so I can make sure this will work in your application.

http://www.914world.com/bbs2/index.php?s=&...t&p=3233422

[tomeric914]

Prototype adapter installed and stack height verified!

It's interesting, different install manuals suggest the stack height anywhere from .100" to .250". This HRB in particular calls out .100" to .150" on a new clutch which seems just a bit too little in my opinion.

I'll get some trans/engine spacers cut for .050"

Next up is designing a bracket to hold the clutch and bleed lines. Not sure if I want to run hard lines or stainless braided with a protective sheath (IMG:style_emoticons/default/idea.gif)

[sixnotfour]

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