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Clutch fork hitting Pressure plate

 
uget2nd
I love my Chevy Chevette!
Posts: 10
Joined: 04/13
Posted: 06/21/13 01:24 PM

I need a little help
My clutch fork is resting on the pressure plate hen at rest,
On my previous post, I mentioned clutch chatter. But I found out it wasn't.
When I press the clutch in and start the car, everything is perfect.(Thats because the face of the fork is backed away from the pressure plate)
As I let the clutch out, you start to hear a chatter. That chatter is the face of the fork hitting the bolts on the pressure plate.
I have a McLeod adjustable throw out bearing, maxed out at 1 7/8 inches in height
My clutch is a McLeod street twin. 3 finger
I us an adjustable pivot ball, but as I back the ball off to give the fork room, It takes away from my clutch  disengagement travel and at the point I am at, the gears are starting to grind.
Can someone give me a pointer or two, in order to fix this problem.

Thanks
                Paul  

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pepsi1
I mow my lawn and find Chevys
Posts: 1718
Joined: 09/11
Posted: 06/21/13 02:05 PM

uget2nd welcome aboard:
The only things that can cause a problem like yours is 3 fold.

1.The trow-out bearing is too short or too long

2.The Fork itself maybe the wrong one.

3.The fork is either too close to the bell housing, or is too short or too long..

You didn't mention what type pressurre plate you. Diagram or fingers. (JUST A LITTLE FYI) a full competition pressure plate with 2800lb-3200lbcould deform a clutch fork in a heart beat...You can always weld they and hets treat them...

Than you need to be concerned about the heighth of the throwout bearing....

Bob

The only other things that couldthe Z-Bar maybe bent or some other bizzarre thing.  

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waynep712222
I have an SS396 tatoo
Posts: 251
Joined: 03/13
Posted: 06/21/13 06:39 PM

is this the type of clutch you installed with 3 fingers and dual discs???

is the clutch fork hitting the 3 nuts on the top of the cover????

5161

just for the rest of us...

this is the info you posted

I have a brand new Mcleod Street Twin clutch, 3 finger, ceramic disks. With this system, I also purchased the SFI bell housing and aluminum fly wheel.

The  engine is a professionally built 427 small block, dino'd at 710 HP.

The trans. is a Lenco, 4 speed ST 1200

The engine and trans. have solid mounts

All parts never on road

The problem I am having is when I release the clutch, the fork vibrates so violently that it broke the pivot ball and bent the rim of the throw out bearing.
I removed the trans, removed and reinstalled the clutch, but the fork rattle was the same when I engaged the clutch,
 

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uget2nd
I love my Chevy Chevette!
Posts: 10
Joined: 04/13
Posted: 06/22/13 03:01 PM

Yes. That is the clutch I have.
They are the bolts.
My problem is that my throw out bearing is maxed out at 1 7/8 inches
I still need another 1/4 inch just to clear the bolts.    2 1/8 inch bearing
Does this seem right
Should I be looking at different angled forks  

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uget2nd
I love my Chevy Chevette!
Posts: 10
Joined: 04/13
Posted: 06/22/13 03:02 PM

Yes. That is the clutch I have.
They are the bolts.
My problem is that my throw out bearing is maxed out at 1 7/8 inches
I still need another 1/4 inch just to clear the bolts.    2 1/8 inch bearing
Does this seem right
What am I over looking?  

Post Reply
waynep712222
I have an SS396 tatoo
Posts: 251
Joined: 03/13
Posted: 06/22/13 06:51 PM

there are several clutch forks that have been clearanced for twin disc clutches...page 63..
i see part #16921, 16922, 16923..  but i don't know which one if any will fit your application.. the catalog is kinda light on details...

those three are listed for modified for twin and long pp... with various combos..


then back on page 80.... this..

SPECIFIC INFORMATION - THROWOUT   BEARING & ADJUSTMENT

A. GENERAL MOTORS
If yours is a 2-piece bellhousing, throwout bearing adjustment is simple: Just look up into the bellhousing and adjust the T.O.

Bearing off the fingers approximately 1/4”. If you have a 360-degree bell housing (one piece), first determine whether or not your T.O. Bearing is of sufficient length and is at the proper pivot angle. To do this, disconnect the adjusting rod so that the fork is free. Move the fork by hand toward the transmission until the T.O. Bearing contacts the clutch fingers. At this point, check the angle of the fork as it comes out of the bell housing. It should emerge straight or be slightly angled toward the motor (see Figure 7). If the angle is toward the transmission (Figure 8), you are past center with the bearing and are losing all mechanical advantage (leverage). To correct this problem, install a slightly longer T.O. Bearing (with flat face) or use an adjustable ball stud. Use our T.O. Bearing part no. 1600 first; then, if it is still too short, use our part no. 1602 bearing or its equivalent (Borg Warner #NI466 or New Departure #CT989S-6) –or their interchanges with local brands carried by your auto parts store.

When using a scattershield and motor plate (Figure 9), it is recommended that you make use of the adjustable ball stud or intermediate T.O. Bearing. To ensure proper adjustment for release on most high performance or drag cars, a hole should be drilled in the bellhousing under the clutch assembly large enough to permit entry of a feeler gauge (Figure11).

B. ALL-MAKE CARS
When adjusting your clutch with a feeler gauge, push the pedal all the way to the
floor board (or pedal stop). Then, by adjusting the clutch rod, slide the feeler
NOTE: ALL FLYWHEELS ARE BALANCED TO FACTORY TOLERANCES. IF YOU HAVE A BLUEPRINTED OR
SPECIALLY BALANCED ENGINE, YOU MUST BALANCE THE NEW FLYWHEEL TO THOSE SPECIAL SPECS.  

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uget2nd
I love my Chevy Chevette!
Posts: 10
Joined: 04/13
Posted: 06/23/13 06:31 AM

What manual did you get this info from, so that I can reference it

Thanks  

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pepsi1
I mow my lawn and find Chevys
Posts: 1718
Joined: 09/11
Posted: 06/23/13 08:33 AM

I always recommend any reciprocating part must go to the balance shop to be balanced with the engine parts. When they are all in sync it shifts like a hot knife threw butter.

Bob  

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waynep712222
I have an SS396 tatoo
Posts: 251
Joined: 03/13
Posted: 06/23/13 01:33 PM

i snipped that right out of the Mcleod 2011 clutch catalog.. i was finally able to download..

i figured you had that one.. and its not an easy one to create a Link for here..

there is a push button on the Mcleod site to download their catalog..

can you list all the part numbers you ordered... or installed..

there are just so many variations to take wild guesses at??

flywheel
clutch and discs
clutch fork
bell housing
throw out bearing

also.. what's it going in??

with that much power it sounds like its going to be a fun ride...

decades ago.. when i had my 66GTO.. the hurst shifter i had was just completely worn out... so i created one out of 3 pieces of bar stock aluminum..  looked like a lenco shifter.. \|/  

3 1 R
4 2
was the shift pattern..  what was neat is i could place it in a forward gear and slip reverse into gear and completely lock the output shaft for parking..  there was no chance of it rolling away that way..  

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waynep712222
I have an SS396 tatoo
Posts: 251
Joined: 03/13
Posted: 06/23/13 01:38 PM

16921

N4obohiv93ttw~~ 12

 16922

$T2ec16z,!Zce9s4g3i4ybrvnwb1w4!~~60 12



16923

$(Kgrhqz,!M!E3kje6grybohi18nikq~~ 12  

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waynep712222
I have an SS396 tatoo
Posts: 251
Joined: 03/13
Posted: 06/23/13 01:43 PM

those sure don't look like they will work in a GM application..  as i said. the catalog was light on info..

but there might not be anything from having you create something with a big notch and reinforcing..

just add the reinforcing before cutting away the gap...   and you might not even need as much as is done there..


say... when i was reading the catalog.. i noticed that the borg and beck LONG cover that you ordered is built with FAST RATIO levers.. so you get more pressure plate movement for less motion of the throw out bearing...

can you with a friend and the push rod disconnected.. measure the amount of stroke from the pivot on the bell crank...

and perhaps rig up something  like some ALL THREAD rod in the push rod area... so you can slowly measure just how much movement you actually NEED to release the clutch..

don't forget.. that you also need to have room behind the throw out bearing/clutch fork as when the discs wear thinner.. to maintain proper throw out bearing clearance when not engaged. the throw out bearing will need to be closer to the transmission face..

thinning of the discs and plates move the fingers farther upward..

so.. if the clutch fork hits the pressure plate top bolts when the clutch is fully depressed.. perhaps you need to examine the ratio of the bell crank.. or even easier.. a stop  block under the clutch pedal...  

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pepsi1
I mow my lawn and find Chevys
Posts: 1718
Joined: 09/11
Posted: 06/24/13 11:18 AM

It's not uncommon to weld bracing across the weak spots.

Bob  

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skyeking
I mow my lawn and find Chevys
Posts: 2738
Joined: 08/09
Posted: 06/25/13 05:38 PM

HI Pepsi Bob!  
skyeking

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