Clutch travel
 

I still have a little scratch sound when I power shift or shift at higher RPMs. I don’t know if I should bring the pedal UP/DOWN or adjust the stop. Before I ever drove the car I brought the clutch pedal up even with the brake. My nephew and everyone else that drove it has commented on how great it drove and the pedal felt it just scratches when you power shift/short shift. Suggestions,?

Only issues (with having the pedal the same height as the Brake Pedal) are:

When you "Power Shift", (with the clutch pedal in the high position), now the clutch pedal might be pushing the diaphragm fingers over center and will cause the parts to fatigue over time.

Something to think about.

You can adjust the linkage to allow the pedal to be higher but now you also increased the distance for the pedal to travel before it bottoms out at the carpet. Pontiac Engineers put stuff in given places for a reason.

Tom V.

Hydraulic clutch, nothing about the setup is stock so I don’t know where to start with Pontiac engineering.

The only way to change engagement or free play with a hydraulic clutch is if you put an adjustable slave cylinder on it.

Most of your basic slaves, especially OEM, are not adjustable. However since your kit is aftermarket they may have supplied and adjustable one as that's pretty common in the aftermarket these days and a common upgrade on newer OEM stuff.

I run mechanical linkage on all my stick cars so adjustment is easy. You'll want a small amount of free play at the throw out bearing so you aren't riding on the throw out bearing all the time. How much free play you give it will affect engagement with the pedal off the floor. This becomes and feel preference per individual.
I prefer my clutch to engage/release at least 3-4 inches off the floor while still maintaining a bit of free play at the throw out bearing. This assures full clutch release slightly before I even hit the floor with the pedal. It's comfortable for me to power shift without moving the pedal so far this way and it's comfortable to daily drive this way as well.

You'll have to play around with it and find a comfortable spot for you.

Lastly, If the clutch is releasing all the way and you have no problem with putting it in gear while sitting still then your high rpm quick shifting gear scratch sounds more like a syncro issue. But try adjusting the clutch first if you have an adjustable slave.

The Syncro issue with the TKO starts with the fact that the gears in the TKO are quite a bit larger than a Muncie, which means they are also heavier, but they use the same size syncro as a Muncie or Top Loader which isn't exactly a good thing as a larger heavier gear is a little tougher to slow down making those Muncie size sycnros work harder. That's been a TKO downfall since it's inception. The fix has been paying extra for better syncros, (carbon fiber lined etc...) as well as modifying the shift levers for smoother operation but that's always been an extra cost upgrade. Works well enough for those of us that street drive the car as well as a little fun now and then. The more serious solution for those that race with these transmissions is to just have the trans converted to a crash box.

Another overlooked issue with the TKO is bellhousing alignment. That has to be spot on because the input shaft uses a taper bearing rather than the old ball bearing on a muncie input shaft. Without proper bell housing alignment it can and usually will cause sticky shifter issues.

What do you mean by scratches? and is this noise coming from the clutch pedal area or from outside the car? Normal driving it doesn't make any noise? Going from memory you used the firewall bracket from Bowler Transmission correct, did you use there master cylinder? I have the kit from Modern driveline and it uses a F body Master cylinder when I first installed the unit it made a bit of scratch noise while depressing the pedal I found that I needed to shim the hiem joint out at the pedal mount to get a straight throw of the rod as it was rubbing against the plastic seal cup of the master and once the system was bled no further issues , but if its only high speed I would verify travel of the master again in relation to the pedal stop, The height adjustment up will have no effect on travel but if you lowered the pedal height at a point it will start to effect travel or it did in my case anyways I ended up shortening the hiem joint that was supplied. Problem is all these kits are for 64-67 Chevelle/ A body cars, The Chevelle must have a slightly different floor pan as all the instructions say the pedal should bottom out on the floor as the stroke runs out on the master. No matter what I did in my car the pedal came nowhere close to the floor( no damage from collision messing things up either) at least 1.5-2" away so I made a pedal stop and this took some adjustment to get it just right

the flywheel that I had to replace looked bluish. I have talked to a few mechanics local who while not performance shops indicated that if I had the stop adjusted too long the clutch was not fully engaging. It may be enough to drive but not enough to “speed shift” does that sound plausible.

As long as the air gap between the release bearing and the clutch fingers is correct the only other option would be the stop. loosen the stop and verify travel and set the stop so as it just touches the clutch pedal as the master strokes out then take it out for a drive. Not sure what you used for a stop mine is just a 3/8 bolt with a sway bar end link poly bushing over the head for some cushion nothing special at all.

If you're getting a little "snick" when you snatch a gear, that says your synchros haven't slowed enough to engage cleanly because the clutch disc is still in contact with the flywheel and spinning the input shaft.

If you're saying you get a little tire chirp with off the gas gear changes, I would have to assume your clutch slave cylinder is releasing too quickly causing abrupt engagement. Does your slave cylinder have an adjustment for bleed-down rate?

Exactly what I'm getting at in post 4, with the added caveat that TKO's are known for this problem and the root cause (clutch aside) is the larger heavier gears have Muncie sized syncro's on them that are in reality a bit too small to effectively slow the gears down quick enough when you get aggressive with the gear stick.

You can adjust the clutch with enough free play and disengagement and still have the gears nip each other when aggressively shifting. That's why these transmissions really need the syncro upgrade when buying them if you plan any aggressive driving.

I adjusted the stop on the pedal. The shifter just falls into place now when shifting normal and feels all around better but it still has a gear clash noise when shifting aggressively. My machinist setup my bellhousing indexing and all the other things so it’s not that I don’t suppose. Did anyone buy their kit from American Powertrain? As usual I can’t get them to answer the phone and the literature doesn’t give me info on which master I have to do research.

Speed shift should be OK but power shift might not be.Tom

I've had these things, with everything else being right, that even a speedy fast shift (off the throttle) is a bit of a problem on a brand new TKO. It's generally not just one gear, it's all of them. This goes back to the syncro being a bit too small, and not being able to slow down the inertia of the much larger gears.

The TKX was supposed to address some of these issues. They've either changed the lining or the taper of the syncro/gear design for more gripping power.

Here is a short video that explains things. Easy to see why the smaller T5 with better syncro design, as well as the T56's with better syncro designs shift so much easier. The TKO is still using an antiquated syncro design that was developed in 1938, and to make it worse, they made the gears bigger and heavier. That's why it's worthwhile to have a syncro upgrade in these things.

https://youtu.be/MXsRfbOiBhE

Yes I buy most of my stuff from American Powertrain.

A TKO is a TKO though, the internals are all the same and not an American Powertrain issue. They just sell the trans, and possibly do upgrades if paid for.

They should however warranty any issue you may have.

Yes its all the gears. Break in period is over so I am about to switch to the GM synchromesh that they recommended I do after break in. Its supposed to be good stuff. Hope it helps

Adjusting the seat position one notch, or adjusting the clutch linkage a little can make a big difference with shifting. Play around with it before doing anything major. No offense, but you seem to make major changes before trying to tweak what you have. A blue flywheel is not good though. A handful of things that could cause that.

I have never driven a car with a TKO but the TKX in my car and the T56 in my buddies 65 GTO both shift super smooth. When I was reading up on the TKX before purchasing it was stated that they had upgraded the synchro's to the same as the T56 trans and or very similar and that it solved the shift issues people mentioned with the TKO. So maybe its just the nature of the beast with a TKO that hasn't had a synchro upgrade that most companies offer?

Blue Flywheel tells you the assy in not happy. Also says you have a potential
explosion waiting to happen.

Assume you are not running a quality certified STEEL or aluminum flywheel, Right??

Tom V.

Assumptions make an ass of you and me! I am running a Ram billet flywheel now, was running a Centerforce before. I am not making any major changes, I am tweaking the pedal around using the stop and the linkage but I am afraid it is what it is. I am not in the habit of driving the hell out of it on a daily basis but it would be nice to not sound like a crash box. If it tears up I will have it rebuilt, otherwise we are gonna rock it till the wheels fall off.

Yeah that's really starting to sound like the common syncro deal.

So normal driving and normal shifting up or down is all okay, it's only when you try to move the shifter quickly. A lot of guys just live with that and deal with it later since they don't get into racing their street cars much.

Yeah as long as I drive like I am driving a “normal” car it is fine. If it give it any real rpm or try to shift it under load it just makes a loud enough noise to piss you off. I mean I paid a lot of money for this thing. I knew I should have gotten the T56 LOL