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Discussion Starter #1
Hello,
I have about 1000 miles on my TKO now, and instead of getting smoother, it has actually gotten worse in shift quality.
I'm using mech clutch linkage, Mcleod 12" clutch assy, Centerforce flywheel, Mcleod scatter shield, Mcleod Slik stick shifter and is filled with GM synchromesh lube.
It's always been clunky and occasionally required a push to get into any gear, but is worse when going from Nuetral into any gear from a stop and shifting has felt very Muncie-like. But these last couple times out, when downshifting 5th to 4th it grinds going into 4th.
I did try readjusting my clutch rod, but it did not help.
The clutch starts to grab about 1" off the floor.
I've never dumped the clutch but have floored it in each gear several times, and done a few runs while speed shifting.
What do I need to look at?
Do I need to pull it and take it in for some warranty work?
Tim
 

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1st if the unit is grinding on a down shift it is time to take it out. Plus how did you get a 12in clutch on a 168 tooth flywheel.
 

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1" off the floor is too close. you're not disengaging the clutch all the way on shifts.

Bring it up to 3-4" off the floor.

Added: If you can't get it there and still have at least a little freeplay on top, you may have a clutch fork or linkage geometry problem.
 

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1" off the floor is too close. you're not disengaging the clutch all the way on shifts.

Bring it up to 3-4" off the floor.

Added: If you can't get it there and still have at least a little freeplay on top, you may have a clutch fork or linkage geometry problem.
Ditto here and you may have wrong clutch fork?? You did install an adjustable pivot arm ball didn't you and have it dialed in the proper 4.75" total depth from rear block face? If you are using a block saver plate , you have to take that thickness in account. TO bearing installed the correct way on the fork? ie. yoke and spring tabs inside bearing throat? Correct 1705 BCA compatable bearing ??? I have yet to see or hear of one that did not shift smoother than a sows inner belly .
 

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Discussion Starter #7
Huh...never felt the inside of a pigs gut, but...thanks to Pink Floyd, and some mind bending substanced I used in my youth, I have seen them fly on occasion.

Yes I have the block saver plate.
I did install the adjustable pivot ball per instructions and I also installed the TO bearing correctly.
The TO bearing is an adjustable style, I removed both rings to make the fork parallel with the flywheel when the TO starts to engage the PP fingers per the instructions.
I chose the 12" clutch to hold the torque. It bolted right up to the FW just like an 11" would.

The TKO kit, fork, TO bearing, clutch assy and shifter all came from the good guys at CC5S. The scatter shield and FW are from Summit.

The scattershield was pre-dialed in by McLeod, and my understanding is that you don't have to re-dial the McLeod's when bolting them to a new engine that has never been line bored, so I bolted it right up per the instructions from McLeod. My engine is a new gen VI ZZ502.

Here's an interesting thing. It shifts between gears up and down and from Nuetral just fine and smooth with the front end off the ground and no power while adjusting the clutch, but when I put the weight back on the front wheels (no power still) the shifting got all ratchety and clunky again.

When I say the clutch starts to grab about 1" off the floor, I mean from a stop with out touching the gas, as I let the peddle rise, this is when the engine starts to slow and the car moves. By the time the peddle moves another 4+ inches, the clutch is fully engaged and there is no slippage at all.

My clutch rod has about .75" of thread left on the forward end after the jam nut, so there is a little room to play with the adjustment, but I'm worried about going too tight and burning my TO bearing up.
 

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Feeling the inside of a sow is part of making sausage and tamales.

You got me on the adjustable TO bearing. Never heard of that on a manual clutch. I used the short flat design with my Centerforce II. Its hard to envision what you are taking about the shifting part with the wheels off the ground?. I can only visualize body flex . Only differance would he the internals gravity pull to the rear of the car??
Have you talked to the CC5 guys about this? I have had the 500 and 600 and did not have any shifting issues after trans break in and I have only changed fluid once in 5K miles. Using GM fluid but will try the new Casteroil type.
 

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When the front of the car is on stands, how high off the floor is the clutch when the tires start to move?

One reason I recently put SFC's on my vert is things were starting to move around. If I put stands under the frame at or forward of the front suspension, everything was normal. If I put them to the rear on the frame, at the firewall, the car would "un-sag" and I couldn't open and close my doors. Perhaps the placement of the load on the stands is moving things around enough to change the clutch adjustment?

I do say again tho, having the clutch start to engage 1" off the floor is too close. If it loads the motor at 1", it is NOT fully disengaged when it is on the floor, and that's why it's hard to shift. Also, I'll bet on normal up and down shifts, your clutch foot never gets close to the floor, I know mine doesn't.

Syncho's were made to fight the mass of the spinning gears, not the torque of the engine.
 

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Discussion Starter #10
I'll give the guys at CC5S a call....thought I'd try here first to see what ideas might be floating around. Also they (CC5S) sometimes reply on the board.

When I have the front end jacked up, the engine is not running, so I'm not looking for wheel movement. Just saying the shifter movement is very free and easy between the gears when I had the front off the ground and the clutch all the way to the floor. Weight on wheels and everything else the same, the shifter gets ratchety and cluncky again....sometimes I need to really force it into gear.

The adjustable TO bearing is actually pretty simple. It has a couple spacer rings in the middle. You pull it apart by hand and remove the rings you don't need. When I was setting things up with the eng and trans out of the car, it seemed I didn't need any rings, so I removed them both.

I drove again yesterday. When I down shifted, instead of going straight down from 5th to 4th, I moved the shifter up into third (did not let the clutch out) and then down to 4th and there was no grinding. So it's just the down shift from 5th to 4th that gets me.

I'll try adjusting the clutch rod some more to see if it helps, but it's sounding like the clutch fork set up is the most likely cause. It's the correct fork (heavy duty from CC5S). The instructions from McLeod didn't mention any specific distances like 4.75" on the adj ball stud from the block face, but they did mention that the fork should exit the bellhousing either slightly angled toward the block or parallel with the block surface. I'm pretty sure it was at least parallel, but maybe should have angled it a bit more, or left a ring on the TO bearing.

Tim
 

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first pull your clutch petal all the way up if it isnt allready. and push down till you just start to get tension from the clutch. that free play should not be no more than 1 inch of play. sounds like you got to much play and thats why it is grabbing 1 inch from floor which will give you downshifting problems you not releasing clutch fully.
 

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Tim
JimM is on the money. It sounds like you don't have enough disengagement. You should have about 1 to 1.5 inches of free play at the top of the pedal travel. The fact that it shifts fine while driving and does not want to go into any gear while stopped is a lack of disengagement problem. A good way to check if you have good disengagement is to have the car running and transmission in reverse while you have the clutch firmly on the floor. Then pull it out of reverse (did you feel a thunk?) now while you still have your foot on the floor try putting it directly back into reverse. If it grinds (don't force it!!!) you need to adjust the linkage to make it longer. Give me a call and I'll help you with more info if you like.
 

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Discussion Starter #13
Thanks, Jim.
I'll try a few things out as suggested and give you a call probably during the week next week.
Tim
 

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Discussion Starter #14
GM Jim,
I still owe you a call. I'll try either late today or in the AM tomorrow.

I made the adjustment rod longer and did get the grinding to stop. The trans shifts much nicer now but I fear the clutch is too "tight" now.

I gave the rod about four turns. The result is the clutch now starts to grab at about 2+ inches from the floor, but the 1" of free play I used to have at the top is now gone. It feels like the TO bearing is riding 100% of the time, and I know that will wear it out fast.

I think I must have made either my adj pivot ball too short, or should have left one or both rings on the adjustable TO bearing (I removed both) and have lost all ability to correctly adjust the clutch.

I'd rather not pull the tranny while laying on my garage floor, but I don't think I have a choice.

Tim
 

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GM Jim,
I still owe you a call. I'll try either late today or in the AM tomorrow.

I made the adjustment rod longer and did get the grinding to stop. The trans shifts much nicer now but I fear the clutch is too "tight" now.

I gave the rod about four turns. The result is the clutch now starts to grab at about 2+ inches from the floor, but the 1" of free play I used to have at the top is now gone. It feels like the TO bearing is riding 100% of the time, and I know that will wear it out fast.

I think I must have made either my adj pivot ball too short, or should have left one or both rings on the adjustable TO bearing (I removed both) and have lost all ability to correctly adjust the clutch.

I'd rather not pull the tranny while laying on my garage floor, but I don't think I have a choice.

Tim
it sounds like your clutch linkage is not pushing the clutch fork far enough. try drilling the bellcrank to increase linkage ratio( effectively shortening the length of the upper arm). this should allow the clutch to be adjusted for propper freeplay, while still acheiving complete disengagement. my $.02
 

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Discussion Starter #16
I assumed to get any actual benefit from adding a hole to the z-bar, it'd have to be closer to the end of the z-bar arm. I looked at my old z-bar to see if there was room to drill a hole further out toward the end, but there is no room.
But you did trigger a thought, similar to the brake peddle having a hole in a different position for manual and power brakes, maybe the same could be done to the clutch peddle arm in order to improve my situation. A hole about 1" higher on the peddle arm might actually work.

Any experts think this is a bad idea? I really don't want to pull the trans if I don't have to.
 

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The only clutch fork I've had work correctly is the GM one. You mentioned a heavy duty fork. I bought one once, as have others, and it's for a 2nd gen and won't give enough travel. The summit one was from Lakewood I believe.

Is the fork you have a 1st gen part? Sounds like you're close! I too would drill the z-bar rather than pull the tranny!
 

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Meanchicken, your thoughts on pedal ratio are backwards!
To get more linkage movement from less pedal movement, you'd need to LOWER the attaching point on the pedal or lower it on the upper arm of the Z-bar. This would rotate the z-bar further, causing the lower linkage to move further.

I'd still wonder about the clutch fork tho. If it was longer than it should be from the pivot out, that would cause the problem. While we don't see many cases where the stock clutch linkage was "designed wrong" we see lots of weird fork issues.
 

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Discussion Starter #19
Meanchicken, your thoughts on pedal ratio are backwards!
To get more linkage movement from less pedal movement, you'd need to LOWER the attaching point on the pedal or lower it on the upper arm of the Z-bar. This would rotate the z-bar further, causing the lower linkage to move further.

I'd still wonder about the clutch fork tho. If it was longer than it should be from the pivot out, that would cause the problem. While we don't see many cases where the stock clutch linkage was "designed wrong" we see lots of weird fork issues.
Thanks.
That's how I do math....backwards.
:)

I am using the 2nd gen "heavy duty" fork. I did not check it against my old fork for any differences and did not realize the geometries were different.

I still remain sure that I left the adj pivot ball too short.

I'm about to finally go call GMJim at CC5S to get his input.

Tim
 

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Discussion Starter #20
OK...I remain convinced that I left the pivot ball too short and did not angle my clutch fork end (the end outside the bell housing) enough towards the engine when I set things up...so the plan for the weekend is to pull out the Z-bar and give the upper arm one or two new holes in 1" spacing downward from the factory hole towards the axis point. I might also pull the peddle assy and do the same with it....one or two new holes spaced 1" apart down from the factory hole towards the peddle.

Barring any interference from the firewall...moving my upper push rod to different holes down lower on one of the two arms should improve my peddle travel but will also make the clutch feel stiffer due to reduced leverage.

If this does not work, then out comes the trans so I can make the pivot ball longer or add a spacer ring or two to the adjustable length TO bearing.

Any final thoughts before I start to damage perfectly good parts?

Tim
 
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