Technical Really hard pressure plate. Need help!

Hey guys, hoping I can find some help here.
I'm putting a a833 trans in my hot rod from a "a" dodge and I am having a hell of a time getting the clutch plates to release. If I put a ratchet strap on the clutch fork it will work, but is really hard at first especially and then eases a bit near the end and I can get it to release, but seams like way more work than necessary. I put a hydraulic pull system on and it barely budges the first 1/8". Any ideas? Shim the pressure plate? I'm at a loss, any help would be appreciated!

 

You may want to list the manufacturers of the parts being used.

 

Using a factory bell? scatter shield (lakewood, ansen, quicktime)? stock style or diaphragm clutch. If you're using a Quick time with a factory fork, i've heard the pivot is not correct and causes issues. I'm planning on a hydraulic TO bearing, so doesn't matter to me, but more details about your setup are needed.

-rick

 

pictures would help a lot....

 

So it's a factory bellhousing, with just a stock style LUK pressure plate. Nothing fancy, I have the 10 1/2 fork that I had to lengthen the forks about 1/2" ( all I could get at the time, I'll get the correct one once i figure this out)
I've posted a pic of the clutch released with a ratchet strap and not under any load

 

picture of the slave cylinder, and how it attaches to the fork, might also help.

Adding length where you did reduces your leverage

 

Ps the hole is from something I was trying where I made a pivet with a bearing and tried to change the fulcrum point, made no difference

 

Clutch master cyl and slave diameters and a pic of the outside would help us understand. But, as Squirrel pointed out, the pivot point location is a likely cause of some of the effort. That could be overcome by changing master and slave sizes though.

 

I had to lengthen the fork at that end to match the pivet, I initially made a pivet to match the fork, but that didnt work and the leverage looked all off.
I'm using a wilwood hydraulic slave cylinder.
(I tried posting a video of everything working but it wont let me for some reason)

 

Pivot and clutch fork length is all the same as a stock "a" body dodge

 

Having the slave cylinder at that angle, not perpendicular to the fork, is not helping things at all. I realize the exhaust pipe is in the way..but something has to give, and what gave was that it doesn't work right.

 

Yes, I was thinking that too, and I'm going to make a new bracket today to straighten that out.
I have put a ratchet strap on from that angle though, and was still really hard to pull in, I feel like it should be a lot easier to move than it is

 

It should be difficult to move the release fork, by hand. There is leverage at the clutch pedal, and you use your leg to press it, so think about the force available at the outer end of the fork.

but also keep in mind that it all needs to be set up to provide the correct amount of movement at the TO bearing to just release the clutch, with the available pedal travel.

And there are several things that will affect the overall ratio, including the fork lenght and pivot location, the pedal length and pushrod location, and the ratio of master to slave bore sizes.

it's tricky!

 

Get a hold of Brewers Performance. They are the 833 pros that you need to ask. They have whatever you need pertaining to the 833.

 

Little update here, I've run out of ideas and I'm pulling the clutch out. I've changed the arm 5 or 6 times now pretty much stays the same. I sent a video to a friend of mine and he thinks something's hooped in the clutch as well now. Suggested i get a 3 finger clutch instead of the diagram.
Anyone here have a situation where they just got a shitty pressure plate?
Mine is a Luk

 

Stick with the diaphragm clutch. I'd do what @lemondana suggested above. ^^^^

First I would get the correct clutch arm and pivot ball and the stock location for the pivot ball. Then if its not working properly, the problem should be in the clutch hydraulics or its mounting. You have to get things right mechanically with the factory type stuff, then concentrate on what you have created to make it work.......therin lies the problem.

 

So now that I've been able to locate a part number on my current pressure plate, Its turns out that it's meant for a jeep Yj,
Gets that's a lesson to always do your own research on part numbers and dont just trust the auto parts store!
Oh well, I'll get the proper one and hopefully that solves my issues

 

Im wondering if there really is that much difference between modern, regular diaphragm clutches. There's got to be some differences but if one requires x lbs to operate are there others requiring say 10x? I really don't know but can't imagine there would be that much difference?

Master diameter, pedal ratio etc had been queried but not answered. I imagine Wilwood has requirements in that regard, I know Ram hydraulic bearings have.

Chris

 

the instructions on the slave installation are fairly specific about location with regard to the apex of travel. For kicks I would move that exhaust out of the way, correct the angle and test it.

 

There was obviously something amiss with the Diaphragm.
The fingers shouldn't protrude to that extent.

 

looks like a typical raised finger diaphragm clutch. There are two types, flat and raised.

 

Also heard them referred as low-cone and high-cone diaphragms.

I probably don't know exactly what I'm looking at in the first photos the OP posted. But something looks odd to me about the interface between the TO bearing and the release fork. Doesn't that style of fork usually have the yoke of the fork straddling a groove cut around the O.D. of the bearing collar? Something about the lugs on that bearing doesn't look right with that style of fork.

And I think there may be a little confusion with some of the terminology used here. Taking your foot off the clutch pedal should engage the clutch. Pressing the pedal down should disengage the clutch.

 

I had a 65 Belvedere with a bb and 833. The pivot was bent a bit and made the whole thing very poor. It was supposed to be 90 degrees, it was about 120. This moved the fork out, misaligning the tips at the TO, and changed the ratio.

All that to say that every part must be proper and aligned with all other parts to work properly. Extending the fork changed that ratio for the worse, and it looks like it's still a bit too short. The pivot is not adjustable, so this is another area where a different part may be needed. Also as mentioned, the hyd. slave is at a wonky angle. If you have rachet strapped the clutch open and measured the disc gap, what was the amount of travel at the end of the fork where the slave engages? Is that the same as the slave throw?
It sounds like you are going to need some measurements and math to get this to work properly.

 

I had a real stiff clutch once when I took a Camaro T5, replaced the tail housing with one from an S10 then bolted it to a 1980 Z28 bell housing while using the clutch/pressure plate/release bearing/flywheel from the same Z28. All used parts. I wanted to assemble and verify everything functioned correctly before spending money on fly wheel machining and a new clutch. In my case, the extremely hard clutch pedal I initially experienced was caused by the used release bearing not fitting the used trans bearing retainer correctly, causing the release bearing to get cocked just enough to bind. The fit of the release bearing felt good on the bench (to me) but clearly there was either enough wear on each part or those two parts just weren't compatible in the first place. New bearing retainer, correct release bearing for the new retainer, and new Luk clutch kit solved my issue.

That being said, I used/built a mechanical clutch linkage, not hydraulic and I copied factory pedal/pedal ratio/Z-bar/linkage geometry.

 

This probably isn't your problem, but I'm putting out there as something to consider if you don't solve your issue.
I had a similar release problem with my clutch/pressure plate (wasn't stock). Ended up the throw-out I used was the stock one and it was too long for the new setup. I got a short throw-out bearing and everything worked great. Good luck.
don

 

I hope there different enough, as I've said I can barely get the thing to move with a ratchet strap

 

This is the current set up, I've got the ram straight to the fork, the tip of the fork dead center on the TO bearing and I believe the best fulcrum point I can come up with, I've tried it as a stock 10 1/2 fork, a 12" fork when that didn't work I whent hotrod and made my own, pivet set back a little with a bushing in the pivet, and the thing still barely moves.
Even if I was off a little I would expect it to move a little better.
I believe I have plenty of travel for the mater cylinder as well.
7/8 bore on the slave with 1 3/8 travel and 3/4 bore on the master

 

Hard to tell exactly whats going on in those pics but it looks like there's a bellcrank in play, but that looks to have a ratio that giving a huge travel reduction?

I'm deducing you're thinking the clutch is heavy due to a problem with the diaphragm, or the alteration of the clutch arm and you've rationalised that by not being able to move it with a ratchet strap. But a ratchet strap doesn't have that much pull does it,compared to say a come along (think length of lever)? My guess is there's something amiss in the master mechanical side. Can you rig up a brake pressure gauge to it?

Chris

 

I looked at your latest photos last night and couldn’t tell exactly what is going on with the linkage for the slave master. @Happydaze hit on something I hadn’t considered, you have crafted a very nice looking pedal assembly that places your master cylinders under the cowl but do you know what your pedal ratios are? Do you have the preferred 6-1 ratio that the brakes and clutch require?

 

Think I'm getting it now, home brewed under dash master setup?

Red arrows show the movement. The green lines show the ratio of the bellcrank that's almost certainly killing the overall pedal ratio. Just a theory.

Chris