Need help getting the clutch to work

[DTraina]

Hi forum - celebrating my first start about an hour ago, and other than a couple of minor leaks and a slightly charred spark plug cable, my Blueprint 306/TKX combo seems to be running smooth and strong. But when I attempted to put the car into gear - any gear - no luck. Just grinding. When the car is off, I can shift into every gear. But once it fired up, no luck. Any suggestions?

Note that it's possible that I may have overlooked something very simple.

[edwardb]

Need more information. Footbox type? Cable or hydraulic? Can you see the clutch arm move when you press the pedal down? If so, do you feel resistance? Did you have the throw-out bearing lightly touching the clutch fingers when the clutch is released? (e.g. not pressing the pedal down).

[DTraina]

Need more information. Footbox type? Cable or hydraulic? Can you see the clutch arm move when you press the pedal down? If so, do you feel resistance? Did you have the throw-out bearing lightly touching the clutch fingers when the clutch is released? (e.g. not pressing the pedal down).

Hi Edward - Appreciate the quick reply. I have a hydraulic clutch, Wilwood pedalbox, and Wilwood master cylinder. Dot 4 fluid. Went through the bleeding process. MC is moving fine, and pedal resistance feels good. Where can I look to see the clutch arm, and the throw-out bearing/clutch fingers? I'm new to all of this, sorry.

[Chopper]

Hi. The clutch arm would be the silver arm sticking out of the black quicktime bellhousing in this picture:

https://photos.smugmug.com/Cars/Cobra/n-PLTRn/i-NN4tb8H/0/55ad338b/XL/i-NN4tb8H-XL.jpg

If you have a clutch arm like above in a hydraulic setup, you will have a slave cylinder like in this picture (blue piece):

https://photos.smugmug.com/photos/i-njGWbqg/0/2f2f9f10/X2/i-njGWbqg-X2.jpg

You should see the arm move toward the front of the car when you push the clutch.

However, you may also have a hydraulic throwout bearing, where two hydraulic lines are coming out of your bell housing where the clutch arm comes out in my pictures. If this is the case, you're going to want to see if you can get some light in that hole and watch to see if you can see the throw-out bearing moving forward inside the bellhousing when pressing the clutch.

[edwardb]

Your Blueprint engine/trans came already assembled? If so, I have to assume they installed the throw-out bearing and clutch arm pivot correctly. When you push the pedal down, you should see the clutch arm move. Like in this video I did several years ago. It should be a little loose without the pedal. But not quite this much. If you don't see an arm coming out of the bell housing like this, you have an internal throw-out bearing. That's a whole different discussion.


https://youtu.be/MgQvEP-gfGQ

[DTraina]

Thanks guys. Yes, I have the housing unit on the TKX, so the slave cylinder and arm are both out of sight. New info: I did just notice a little bit of fluid on the 1" tube below the connection point on the hose going into the housing. Need to rebleed the system?
173125

[edwardb]

Thanks guys. Yes, I have the housing unit on the TKX, so the slave cylinder and arm are both out of sight. New info: I did just notice a little bit of fluid on the 1" tube below the connection point on the hose going into the housing. Need to rebleed the system?
173125

Based on your picture, you don't have a clutch arm or slave cylinder. You have a hydraulic throw-out bearing. Meaning those pictured hoses are going direction to the device on the input shaft of the transmission and directly pressing on the clutch. Briefly shown in this video clip. https://youtu.be/0L-6CU-C51Q?t=24. Proper installation and setting the gap is critical to how they operate. But I'm assuming Blueprint set it up properly. They are not beginners at this.

It needs to be bled to work properly. Air in the system will prevent it from working. So will leaks. That needs to be resolved. For the two hoses, the bleed line needs to be on the top line of the throw-out bearing. The pressure line on the bottom. Otherwise it may not bleed properly. Did Blueprint specify the lines to use? Also, did Blueprint specify what size master cylinder to install in your footbox? That is also critical to it working properly, e.g. having the proper amount of throw.

[mladen]

I'm not sure if we have the same setup, but I recently got my 427 from Blueprint that has a TKX and a throwout bearing. Here's some additional info I got from them on setting it up that may help.

https://www.mcleodracing.com/product/download_file/I0014_Slip-On_Hydraulic_Bearing_Instructions_Revised_V2.pdf

EDIT: You can disregard parts of that doc because your bearing is already installed, but it does provide a good overview of the whole setup.
EDIT2: I have the complete kit and the Wilwood pedal box and MCs. They are as close as what I'd consider to be in spec for what that doc describes :)

EDIT 3: Here's one more doc specifically on bleeding https://www.mcleodracing.com/product_images/mcleodracing/installation_instruction-instruction_file-91-v1.pdf

[Mike.Bray]

Sounds like you have a hydraulic throwout bearing. These things don't have very much travel so it is imperative to get the gap between the bearing and the pressure plate fingers set to the recommended spec (the Tilton is 0.125"). There's nothing special about what I'm running, SBF/Ram flywheel & clutch/TKX, and a Tilton hydraulic bearing. But I had to make a spacer to get the bearing in the correct position.

https://www.imagecoast.com/images/MichaelBray1/cimg0489.jpg

[Lidodrip]

I would echo edwardb's comments about making sure you have the correct master cylinder size for your HTB - I had to get a different one than what was supplied by FFR. If your hydraulic bearing system seems to be working correctly, the other thing to consider is that your flywheel maybe stuck to your clutch. This can happen with some surface corrosion on the flywheel that has been sitting for a while. There are several posts about this on this forum and a couple different methods to get them unstuck (running the engine while on jack stands or using rolling force if on the ground).

[Mike.Bray]

I would echo edwardb's comments about making sure you have the correct master cylinder size for your HTB - I had to get a different one than what was supplied by FFR.

I can tell you for the Tilton it calculated to use a 13/16" MC.

[JohnK]

If you're observing a small leak, then you definitely need to address that and re-bleed the system. I had a problem with a persistent leak from the bleeder on my hydraulic throwout bearing (read about it here (https://thefactoryfiveforum.com/showthread.php?40895-Clutch-hydraulic-leaks-some-answers-and-more-questions)). Even a tiny leak will let air in and the HRB will not work properly. Use a good thread sealant on any NPT fittings and check the sealing surfaces on any AN fittings (no sealant) to make sure they're clean and burr-free. Then wait a while after bleeding and go back and check with a paper towel to confirm that they're all leak-free.

[Railroad]

There has been an incident of the pressure plate rubbing the lines, creating a leak in one of the hoses. The hoses need to be restrained from contacting the rotating parts of the clutch.
Good luck with the repair.

[CraigS]

When checking for tiny leaks I like to rub all around the joint w/ the pad of my finger and then look at it to see if there is any moisture. I find this much more reliable than just looking. It also lets you check the back side of the joint w/o resorting to a mirror.

[DTraina]

Hi guys. I think in solving my hydraulic clutch problem I've discovered another problem. After multiple bleeds I was confident that there was no air in the system, but I still cound not get the clutch to disengage.

I decided to try messing with the Wilwood master cylinder push rod and after adjusting it about 1/2" (lifting the clutch pedal away from the floor) that seemed to do the trick. The clutch finally disengaged and I was able to shift into gear. So I fired up what I hoped was finally my rolling chassis and started a slow roll in 1st gear, but quickly stopped because there was an audible grinding noise coming from the tranny.

I feel like I'm close, and that at this point it's just a simple adjustment that needs to be made. But searching through the forum and my Wilkwood instructions isn't getting me anywhere. Help! And thanks again.

[edwardb]

Hi guys. I think in solving my hydraulic clutch problem I've discovered another problem. After multiple bleeds I was confident that there was no air in the system, but I still cound not get the clutch to disengage.

I decided to try messing with the Wilwood master cylinder push rod and after adjusting it about 1/2" (lifting the clutch pedal away from the floor) that seemed to do the trick. The clutch finally disengaged and I was able to shift into gear. So I fired up what I hoped was finally my rolling chassis and started a slow roll in 1st gear, but quickly stopped because there was an audible grinding noise coming from the tranny.

I feel like I'm close, and that at this point it's just a simple adjustment that needs to be made. But searching through the forum and my Wilkwood instructions isn't getting me anywhere. Help! And thanks again.

Adjusting the standard Wilwood master cylinder(MC) and pedal is pretty straightforward. With the MC bolted in placed in the pedal box and the clutch arm not attached, the pushrod should be all the way out against the MC's internal stop. It's easy to do because there's a spring that pushes it out against the stop. Then thread the clutch arm clevis onto the pushrod stopping when the pedal is at the desired height. Some (like me) prefer the clutch pedal to be the same height as the brake pedal. Some like the clutch pedal higher than the brake pedal. There's enough adjustment to be either way. But the wildcard here is the MC size. If not the right size, it's possible even pushing the pedal all the way to the floor doesn't release the clutch. Of course the wrong size could also overdrive the release bearing, meaning a pedal stop is required (or the right size MC). I asked this before, but did you get a recommendation on the right MC size? Note it's possible if the MC isn't sized or adjusted properly, an adequate bleed may not be possible.

[AROCK]

The first thing you should have done was check the bell housing. run out. If the bell housing turnout is greater then .005 then you have to use off set bell housing dowel pin to bring the TKX back under those tolerances. The Tremec has to be lined up straight with the crank or it will grind. Or not go into gear.
Look up what I am saying on the Tremec installation instructions. Your throw out should be set at .100- .125 from the clutch diaphragm face.
Also if you have a 3/4" MC you should be ok.

[Lidodrip]

Adjusting the standard Wilwood master cylinder(MC) and pedal is pretty straightforward. With the MC bolted in placed in the pedal box and the clutch arm not attached, the pushrod should be all the way out against the MC's internal stop. It's easy to do because there's a spring that pushes it out against the stop. Then thread the clutch arm clevis onto the pushrod stopping when the pedal is at the desired height. Some (like me) prefer the clutch pedal to be the same height as the brake pedal. Some like the clutch pedal higher than the brake pedal. There's enough adjustment to be either way. But the wildcard here is the MC size. If not the right size, it's possible even pushing the pedal all the way to the floor doesn't release the clutch. Of course the wrong size could also overdrive the release bearing, meaning a pedal stop is required (or the right size MC). I asked this before, but did you get a recommendation on the right MC size? Note it's possible if the MC isn't sized or adjusted properly, an adequate bleed may not be possible.

I have a Tilton 6100 HRB and when I first installed it with the FFR supplied 3/4" Wilwood MC, I could not get the clutch to completely disengage (even though it would mostly disengage). Without complete disengagement, you will get grinding. The Tilton instructions called for a 13/16" MC which I swapped in - problem solved. I had read where some had luck using the 3/4" MC with the same HRB, but that was not the case for me. Even though the size of the new MC was only 1/16" bigger, it did result in a close to 20% increase in volume. Your HRB instructions should have a chart of the recommended MC sizes based on the clutch you are using. Good luck, you are close - I know the feeling!

[Mike.Bray]

I have a Tilton 6100 HRB and when I first installed it with the FFR supplied 3/4" Wilwood MC, I could not get the clutch to completely disengage (even though it would mostly disengage). Without complete disengagement, you will get grinding. The Tilton instructions called for a 13/16" MC which I swapped in - problem solved. I had read where some had luck using the 3/4" MC with the same HRB, but that was not the case for me. Even though the size of the new MC was only 1/16" bigger, it did result in a close to 20% increase in volume. Your HRB instructions should have a chart of the recommended MC sizes based on the clutch you are using. Good luck, you are close - I know the feeling!

I did the calculations for my Tilton 6100 HRB and it came out to a 13/16" MC which seems to work perfectly. Clutch fully disengages and pedal effort is light and smooth. If you look at volume 13/16" diameter is quite a bit more than a 3/4".

[AROCK]

Look!! If bellhousing runout is not checked and meets the .005 or less run out in relation to the transmission alignment to the crankshaft then the clutch doesn't matter.
Tremec will tell you the first thing to check if your transmission is grinding going into gear is the bellhousing run out. You can talk about your MC volume call you want if the alignment is above .005 your transmission will bring going into gear. Enough Said!

[Chopper]

Do blueprint engines come with the transmission already connected to the bellhousing? If so, Blueprint probably checked this for him. I'm betting the MC size is the issue as others have suggested.

[DTraina]

Hi guys - update! I did a ton of research and confirmed that this particular hydraulic clutch system from McCleod requires a 3/4” master cylinder, so I kept looking elsewhere for a fix. I ended up messing with the pushrod, lengthening the throw of the pedal and ultimately that got the clutch to disengage. I took her for a few laps around the neighborhood. Success!

What bugs me now is the length of the stroke - I have to practically straighten my leg to fully depress the pedal and disengage the clutch. I still hear a slight grinding noise as I’m transitioning between gears - that may or may not just be the normal sound of the clutch disengaging. I’m planning to have a pro mechanic do the final adjustment just in case.

[Jeff Kleiner]

What bugs me now is the length of the stroke - I have to practically straighten my leg to fully depress the pedal and disengage the clutch.

Changing to a larger diameter master will reduce the travel however effort will increase. It’s all a balancing act that comes with compromises.

Jeff

[sam_sturdy]

I have a Blueprint 302/T5 setup and experienced much of the same. I have a hydraulic clutch (same master and slave size as Forte) and that works well. When I press the clutch, the clutch fork hits the bell housing and restricts the clutch from disengaging. I have grinded a lot of aluminum away for more clearance, but still not enough to get the transmission into reverse most of the time. I'm curious if anyone has had this issue or if you can see if your setup is doing the same.

[Avalanche325]

That slight grinding noise is not normal. You probably are not getting full disengagement. You also do not what it where it disengages at the very end of pedal travel. When driving hard and shifting fast, you are likely to grind the gears, which gets expensive.