1G Another disengagement issue...but this time, EVERYTHING is new...

[92nolatist]

Ok so I installed my Shep stage 3 trans and Southbend SSX clutch with Kevlar disk and ACT Streetlite flywheel, along with NEW: OEM clutch master, slave, SS clutch line, fork, pivot ball, TOB, and a rebuilt and welded pedal assembly. Now heres the issue, the pedal grabs about an inch off the floor and the adjustment rod is threaded ALL the way out (cant thread out anymore because it will fall out the the nut thing). Shifting is notchy and sh*tty.

Personally, I dont want to ruin my brand new clutch and expensive ass f*ckin transmission so I called Shep today and talked with Trevor. He said hes only heard of this situation 2 or 3 times; he suggested to check to make sure my fork is not hitting the trans when the clutch is depressed, because that could cause an issue. I checked tonight and its not, plenty of room before hitting. He said if thats OK, then put in a longer slave rod even though its not recommended, thats all he could think of.

So since everything is BRAND FREAKING NEW, the clutch shouldnt be doing this. Im pissed off because I replaced everything so I wouldnt trash my new trans....

If I have to put in a longer rod, I will, but Id rather not. Im trying to think of anything else it could be Master push rod too short maybe? I bought everything from ExtremePSI so I know its not some garbage junk placed in a mitsu box.
Please people, help me out. Thank you.

 

[TalonJohn94]

I used 4 thin washer to shim the pivot ball, and welded a small nut to the C-clip on the pedal assembly that grabs the master cylinder to give me just about another few centimeters of adjustability.

The disengagement point has been rock steady for years now which I honestly was surprised about. And the ACT 2600/XACT setup I use has been one of the most reliable things on my car.

So, if all else fails I suggest extending the master cylinder rod or welding a nut.

 

[92nolatist]

So Im guessing that once the pivot ball is shimmed, Ill have to readjust the master cylinder rod? Because obviously the engagement point on the pedal is moved higher, right?

 

[LiquidX]

Correct

 

[Nekid]

I know the answer to your problem as I went through the same ordeal. The SBC is thicker (in my case, it was 20 thou thicker than the ACT clutch I eventually got) than the ACT PP is designed for. You are operating outside of the effective range of the PP springs; they are not linear, so when you get outside of that window, you have to drastically increase the movement in the hydraulics. Or another way of putting it, the first say 1/2 of travel moves the PP more than the last 1/2 of travel...with your current scenario, you are already in that last half because of the thickness.

Your "bolt-on-options" are:
1) get the SBC PP
2) get the ACT clutch
3) machine your flywheel to increase you step height

What I did was get the ACT clutch.

 

[92nolatist]

I already have the SBC pp and disk, as stated in first post.
I don't want an ACT, had one before and didn't like it.
I'm def leaning towards machining the flywheel and maybe shimming the pivot ball for extra measures. Gonna call Southbend and see what they recommend for a step height.

 

[LiquidX]

I'm still towards it needing shimmed.

 

[92nolatist]

I am too, I don't know why I didn't do it in the first place. I left a message with SBC, waiting for a call back about recommended step height....

 

[T is for TURBO]

Let us know what you find out!

 

[Nekid]

I already have the SBC pp and disk, as stated in first post.

Yep, read it a bit too fast the first time, I saw SBC disk and then saw ACT and figured "oh...that setup", without realizing it was SBC PP and disk on an ACT flywheel.

Anywho, the heavy Southbend pp's suffer the same problem with their own disk.

When you pull the tranny, measure the thickness of the clutch disk.

My SBC disk was 340 thou and the ACT disk I replaced it with was 320 thou. Even now with the 610 thou flywheel, 320 thou disk, 40 thou pivot ball shim, on my ACT 2600pp, I have the master cylinder backed out all the way and I am ever so slightly dragging at 7500. If I was staying with a single disk setup, I would be really tempted to increase the flywheel step just to move around my engagement point higher up. Stepping the flywheel to 620 thou may not be enough, but I guess wait until you hear back from SB. Another person to inquire about this is Tim Zimmer at tmzperformance.

 

[92nolatist]

I just bled my clutch again tonight using TREs method and it is a little better, meaning its very slightly higher at the pedal, but not by much. I wanna call him to see what to see he says as well. I'll do that tomorrow.

 

[T is for TURBO]

I was able to snap a photo of my clutch fork location today. It looks to be pretty much in the same location as yours. I wonder if these disks/pp just require a closer fulcrum?

My setup:
Comp Clutch forged clutch fork
Brand new pivot ball
South Bend SS-Series pressure plate
TZ-Series Kevlar clutch disk (full face, sprung)
Stock Flywheel

I just bled my clutch again tonight using TREs method and it is a little better, meaning its very slightly higher at the pedal, but not by much. I wanna call him to see what to see he says as well. I'll do that tomorrow.

Is the shifting still notchy?

 

[____Kurt____]

Oh man Dal, and mine is still to the left of the middle, I hope that twin disk works because I dont fee like pulling my tranny. Is there enough room to shim the pivot ball though the window or you have to pull the trans?

 

[Nekid]

You have to pull the tranny.

Another way to check for correct combined thickness and step, is by taking a look at the PP fingers when it is all bolted up. The PP fingers should be outward a bit, not flat nor pointing in. In my case with the thicker disk and stock flywheel step, the fingers were flat. I didn't know that at the time and bolted everything up only to find the clutch engaged 1" from the floor when the MC was adjusted.

 

[ed1380]

The way I like to do it, is to push the slave piston/rod in by hand and see how much it'll go back into the cylinder. I call that the slave freeplay. I aim for 1/4 to 1/2" so I get the full travel/disengagement from my slave piston.

 

[92nolatist]

It's not really notchy anymore, but I will get a crunch every now and again.... Yea Kurt, I'm thinking you need to shim your ball, that's fork needs to be to the right more.

 

[LiquidX]

Not the best picture but this is how mine sits.

 

[T is for TURBO]

Where in the pedal travel to does your clutch start to grab?

 

[LiquidX]

About half I think. I haven't driven it much.

 

[____Kurt____]

dial caliper will not give you a good measure. You need a depth mic. I went through this more than a decade ago.

According to RRE, they use a dial indicator.
RRE's Clutch And Flywheel Tech Info

 

[92nolatist]

No no kurt, theyre using a dial indicator, much different than a dial caliper. And when I said that I used a dial caliper, I used the back end of it, much like the way a depth gauge is used.

 

[twicks69]

I rebuilt and welded the assembly myself, there was nothing that could have gotten messed up, it was a simple procedure.

I personally measured the step myself with a good dial caliper. I work in a shop so I do everything myself and Im very meticulous about how everything is. Ill contact Tim Zimmer and ask him, thats who I bought the clutch from, via TMZ Performance.

Sorry I didn't see this until now; I have been out of town.

The SBC clutches require a flywheel step height of 0.610"-0.612".

As for parts used; did you adjust the master cylinder rod away from the firewall as far as possible before bleeding the clutch hydraulic assembly? You want to bleed the system making sure you are seeing total throw of the master cylinder rod. If you are still having engagement issues, you should adjust the rod out, then bleed the hydraulics several times more to ensure no air in the system, or reverse bleed the system to draw any air in the system upwards through the master cylinder reservoir (have tube off of slave cylinder bleeder into a container of brake fluid, bleeder opened, then vacuum draw through master cylinder with vacuum pump and external reservoir).

As for other details, there should be no slop in the clutch pedal or clutch fork/pivot ball/TOB assembly.

The TOB clip should be engaging the TOB around the outer circumference of the TOB locking into the tabs on the fork and overlapping the side tabs and top edge of the TOB if using a stock clutch fork. The Competition Clutch forged steel clutch fork has its retainer clip holes slightly offset resulting in only the side tabs to engage with the TOB clip.

You should only use a Mitsubishi OEM pivot ball; no shims.

You should always use the OEM starter plate.

Never use a slave cylinder rod extender or shim the pivot ball with SBC products.

You may be over-disengaging the clutch if you are adjusted too far on the master cylinder rod/pedal assembly. Adjust out the rod, bleed the system, readjust the pedal assembly. Confirm that there are no leaks or air in the system.

 

[92nolatist]

Step height is .610
The rod is screwed out as far as possible. This is the ONLY way the clutch will disengage, and its definitely not over-disengaging. When I first put the pedal assembly back in, I had the rod all the way in and tried putting into gear and it wouldnt go, readjusted a little and so on and so forth until the rod was all the way out; pedal grabs an inch off the floor.
System was bled numerous times with the rod all the way out, using the TRE method.
Pedal assembly is rebuilt with new lever and z-bar with brass bushings and welded correctly, by myself.
Master, slave, SS clutch line, TOB, pivot ball, fork-all new.
TOB clip is installed correctly.

All this was said a few times thoughout the thread...

Thank you Tim, for responding but what you said was what everyone else pretty much said. Im not bashing you in any way, I was just hoping that you could have told me something that no one else suggested.


I called SBC back and they said the flywheel needs to be at .610, nothing else and thats what its at. So, Im going to shim my pivot ball, regardless if some of you think otherwise. Every component in my clutch system is in perfect working condition, and there is nothing more that could cause a low disengagement. I agree with Gold Diamond and the fact that aftermarket PP have different geometry and need to travel further than OEM PP, so thus shimming is required. I will report back after I pull the trans and shim the ball, its the only logical suggestion and its what makes the most sense to do.

 

[ed1380]

Try pushing the slave cylinder piston back in. How much will it go in?

 

[T is for TURBO]

Did you get this straightened out?

 

[92nolatist]

UPDATE
So I pull my trans tonight and shim my pivot ball with two washers equalling .176 inches, anymore and the fork will hit the PP. My fork is sitting about 1/4 inch to the right of the center line in the window. I put everything back together and go to test it out; well much to my surprise and dismay, the pedal engages in THE EXACT SAME SPOT, if not lower!(which is an inch off the floor) The master rod is adjusted all the way out just to the point of still being able to push the slave in.

I thought the engagement point was supposed to get higher by shimming the ball??? WTF is going on here?? WTF did I do wrong?? Im very frustrated and pissed off.

I did have someone on here message me when I first put this thread up (not gonna mention names), and he said that he too had a SBC with kevlar disk and told me that the kevlar disk is too thick, and he switched to an ACT disk and everything was fine. Could this be the whole issue??????