Drivetrain Tko600 Clutch Adjustment Issue

[DonMaximo]

I installed a TKO600 into my 92 foxbody.

I'm using an Aluminum flywheel and a Spec 2+ clutch.

The problem is that I must put quite a bit of preload onto the Clutch Adjuster at the firewall in order to allow the car to shift.

It's my understanding that I should have some 'play' in this clutch pedal, but I cannot change gears unless I twist the adjuster way out.

Before removing the tranny and bell housing, I wanted to fish around for possible explanations on what the issue might be and the best methods for confirmation.

Pilot bearing ? Clutch Fork adjustment ball ?

All advise appreciated.

 

[jrichker]

Clutch pedal adjustment with aftermarket quadrant and cable: I like to have the clutch completely disengaged and still have about 1.5” travel left before the pedal hits the floor. This means that I have only about 1” of free play at the top before the pedal starts to disengage the clutch. Keep in mind that these figures are all approximate. When properly adjusted, there will not be any slack in the clutch cable. You will have 4-15 lbs preload on the clutch cable.

Adjustable clutch cable tips:
Loosening the cable adjustment nut (throwout bearing arm moves to the rear of the car) moves the disengagement point towards the floor.

Tightening the cable adjustment nut (throwout bearing arm moves to the front of the car) moves the disengagement point towards the top of the pedal.

The next step doesn't make much sense it you already have the transmission installed, but just for sake of discussion, here it is:

The throwout bearing sits in the clutch fork arm with the wave springs pressing on the rear flange of the throwout bearing.

Major differences between the distance between the flywheel surface and the clutch fingers may require tinkering with the clutch fork pivot ball. Stack your old clutch, pressure plate and flywheel up like they were when installed in the car. Tighten down all the pressure plate bolts and measure the distance between the clutch fingertips and the flywheel face.
Too much thickness will cause the clutch fork arm to sit too far back to get the clutch cable on the quadrant. It may even sit against the rear or the bell housing hole for the clutch fork arm. In that case reduce the pivot ball height.
Too little thickness will cause the clutch fork arm to sit too far forward and bottom out against the front side of the bell housing hole for the clutch fork arm.. This will prevent the clutch from fully disengaging.
In other words, the clutch fork arm should sit positioned midway or a little towards the rear in the bell housing hole for the clutch fork arm when the cable is properly tensioned.

 

[DonMaximo]

Clutch pedal adjustment with aftermarket quadrant and cable: I like to have the clutch completely disengaged and still have about 1.5” travel left before the pedal hits the floor. This means that I have only about 1” of free play at the top before the pedal starts to disengage the clutch. Keep in mind that these figures are all approximate. When properly adjusted, there will not be any slack in the clutch cable. You will have 4-15 lbs preload on the clutch cable.

Adjustable clutch cable tips:
Loosening the cable adjustment nut (throwout bearing arm moves to the rear of the car) moves the disengagement point towards the floor.

Tightening the cable adjustment nut (throwout bearing arm moves to the front of the car) moves the disengagement point towards the top of the pedal.

The next step doesn't make much sense it you already have the transmission installed, but just for sake of discussion, here it is:

The throwout bearing sits in the clutch fork arm with the wave springs pressing on the rear flange of the throwout bearing.

Major differences between the distance between the flywheel surface and the clutch fingers may require tinkering with the clutch fork pivot ball. Stack your old clutch, pressure plate and flywheel up like they were when installed in the car. Tighten down all the pressure plate bolts and measure the distance between the clutch fingertips and the flywheel face.
Too much thickness will cause the clutch fork arm to sit too far back to get the clutch cable on the quadrant. It may even sit against the rear or the bell housing hole for the clutch fork arm. In that case reduce the pivot ball height.
Too little thickness will cause the clutch fork arm to sit too far forward and bottom out against the front side of the bell housing hole for the clutch fork arm.. This will prevent the clutch from fully disengaging.
In other words, the clutch fork arm should sit positioned midway or a little towards the rear in the bell housing hole for the clutch fork arm when the cable is properly tensioned.

For many years now, you have weighed in. Truly grateful to have your feedback.

#1 - I no longer have my old parts. They were sold with the older motor.

I dropped the tranny yesterday, inspected all the relatively new components and all looks well. Upon reinstallation, I only removed the large lock washer from the stock pivot ball (PB). The Lakewood adjustable PB from LateModelRestoration was far too short and would have bottomed out.

I'll call Maximum Motorsports Monday to inquire about the dimensions of their adjustable PB.

By removing the washer, the cable side of fork moved forward 0.33". This allowed me to put OEM cable end on fork without effort/pressure upon the fork. There was slack in the pedal now. I have an aluminum quadrant and firewall adjuster was flush to the wall. So, I thought I might be making progress.

Despite this, I still have to turn-out on the firewall adjuster in order to make the clutch operable. In fact, car will not shift properly unless I remove all slack from the pedal and actually apply preload to the fork. I believe the preload is excessive as I MUST pulled on the cable while turning adjuster out.

Taking your reasonable comments into consideration, the behavior suggests my new Aluminum flywheel and clutch assy is thicker than stock.

I'm trying to get my head around a single question.

"Why do I need so much Preload in order for the tranny to shift ?"

Fingers should only have to move a certain distance in order to work.

I'll also call SPEC on Monday.

**
At this time, my action items are:
#1 - Call Maximum motorsports to acquire the dimensions with their PB.
I will also share this issue.
#2 - Call Spec
Explain symptoms and go from the there.

 

[jrichker]

You should have zero slack in the cable a 4-15- lbs. of preload tension on the cable

 

[rd]

Interesting info. I just converted my 66 Malibu to a T5 from a Th350. I broke two throw out bearings messing with the clutch.

From my brand c escapade, it appears the tb should be clear of the clutch fingers when disengaged, and allow full disengagement. Mine worked out, but I got another fork, an adjustable pivot ball and have adjusted it a bunch.

I jumped in here because I just ordered a tk0 600 for the car. Excited, except I have to take all apart again....