Wilwood Pedal Box Clutch Clearance

[John J Phillips]

Some days I just feel stupid. Today is one of those. I put together the Wilwood Pedal box - easy. When I attach to the firewall and place the rear mount, the clutch pedal hits the 3/4" angled frame rail. I have about 3" of clutch travel before it hits the frame. Went back over everything but clearly I am missing something. Thanks in advance for your thoughts.

[FMJ]

Is this what you're talking about?

-Fred
4249642497

[John J Phillips]

Yes, clutch arm hitting the frame rail.

[FMJ]

I went back and forth with Factory Five on this and at the end of the day they were aware of it. Keep in mind my kit is from 2011. The only choices to my knowledge are switch to the previous version of clutch pedal (see below), put some type of block at the back of the pedal box or trim the pedal. Now some folks actually cut the tube and repositioned it however welding is not in my wheelhouse.. Others can chime in if they know of a better solution.
42498
42499

[edwardb]

Widely reported problem, and discussed a bunch on this forum and the other one. The timing of the interference seems to coincide with the release of the larger Wilwood pedal arms. Makes sense. You basically have two options. Relief on the pedal arm (e.g. remove material) or relief on the 3/4 inch tube. I wouldn't think of going back to the old pedal arms, since they were changed because of reported breakage. On my Mk4 with the same issue, I chose the 3/4 inch tube. Even though people way smarter than me say it's structurally sound to remove some material from the clutch arm, I'm just not comfortable going that way. If you choose the 3/4 tube for relief, lots of choices. Some have just beat on it with a hammer (not my choice), others have done some really nice fab and welding and put in an angled relief. I don't weld, so I chose to cut the tube, and splice a new piece on the outside. This really isn't the best pic, because it's dark plus everything is powder coated black. But it's the only one I have. If you zoom in on the area in question, you can see the beginning and end of the piece that was added, and where the 3/4 inch tube was cut. The piece that was added is solid, and there are inserts inside the 3/4 inch tube where the bolts go through. Easily as solid as before, but with plenty of clearance.

http://i867.photobucket.com/albums/ab234/edwardb123/Factory%20Five%20Mark%204%20Roadster%20Build/Update%2011212012/IMG_1877.jpg (http://s867.photobucket.com/user/edwardb123/media/Factory%20Five%20Mark%204%20Roadster%20Build/Update%2011212012/IMG_1877.jpg.html)

[Erik W. Treves]

Notch it and move on...if you have rely on the amount of material you have to remove from a structural stand point... you are going to have a lot more stuff to worry about....my .02

[John J Phillips]

As always, timely and good advice from those who have gone before. Not certain which solution I will use, but at least I have a direction and it is not something I put together incorrectly.
Thanks to all
john

[rmiller64]

John, I choose to notch the new pedal. The new ones have more structural webbing. If you choose this route don't leave a sharp 90 degree corner. I used a carbide cutter that left a nice rounded inside corner.

Good luck

42506

[christenfreedman]

John, I choose to notch the new pedal. The new ones have more structural webbing. If you choose this route don't leave a sharp 90 degree corner. I used a carbide cutter that left a nice rounded inside corner.

Good luck

42506

Yup, just notch it and move on...

[carlewms]

Ditto on notching the pedal webbing ... You do not lose that much strength by doing so as long as you don't cut into the main section of the arm.

[edwardb]

Here's more information. The original pedals, as I understand, were cast aluminum. I personally never saw them. My Mk4 was later. Anyway, there were several reported instances of them breaking. You can find some threads over on the other forum where guys reported the breakages. This post has a picture of where they broke: http://www.ffcars.com/forums/2335911-post45.html Subsequently a new beefier forged aluminum one was made available from Wilwood. Some guys reported the new pedal arms as steel. But they're not. They're definitely non-ferrous. I have them in my Mk4 and I checked them with a magnet. The beefier arms became standard and were provided with all kits going forward. Around this same time the issue with the new arms interfering with the 3/4 inch chassis tube was reported.

So the part of the pedal that was breaking is not in the same area as where material needs to be removed should you choose this approach. Plus the newer pedal is made of stronger material and beefier, as already mentioned. So it's probably safe to remove some material from the clutch arm. Care should be taken to not remove any more than absolutely necessary, as already mentioned. For me, just on pure principal I chose to modify the 3/4 inch chassis tube. I just didn't want to cut into the arms. But either way should be OK.

[skullandbones]

It's probably OK to modify the back side of the pedal as described by some poster now that the overall structure has been changed to a forged piece. However, the more conservative route is to change the chassis tube rather than the pedal. It's easier to modify a simpler structure such as this 3/4 inch tube. It has been done for several mods such as making room for a standard size brake booster when using an external MC in the engine bay driver's side. It would be just as easy to modify the chassis tube by notching it out and reinforcing it with a similar 3/4 inch tube along the back side. There is ample room of surface area for welding the two tubes. The added benefit is if there is a problem with the pedal later, the pedal would be unchanged so no warranty issues. I go along with "edwardb" on this one. You shouldn't sweat it either way though.

Good luck,

WEK.

[smithbks]

I actually modified both...by accident. Early on while adjusting the clutch cable I depressed the clutch pedal multiple times. At first I thought the resistance was from the clutch, which was stuck at first and had to be broken loose. So after pushing the pedal rather hard several times I unintentionally notched the pedal slightly. As edwardb mentions, it is aluminum so it sort of compressed a nice dimple in the arm. But to get enough room I also had to cut a slight V out of the tube with a Dremel tool. As a result, I have a small notch in both. As it turns out from the above discussion, that might be the best compromise!! Dumb luck at its best.

[David Hodgkins]

I just did this last weekend. I didn't cut all the way through the 3/4" tube; I notched it. Now it acts as a pedal stop and the clutch stops just 1/8" from the front foot box wall:

http://thefactoryfiveforum.com/attachment.php?attachmentid=42532&d=1433776514

http://thefactoryfiveforum.com/attachment.php?attachmentid=42533&d=1433776516

I think this is a better solution that notching the arm. You can see where I started down that path before reconsidering.

:)

[chopthebass]

David, you have taken quite a bit of meat out of the 3/4" tube - is that going to weaken it? I haven't started my build yet, but I do prefer this idea!

[R Thomas]

Off topic, but am I looking at a Wilwood Pedal box with a hydraulic clutch and Hydro-booster power brakes? Referring to pic enclosed by Edward B.

[Arvin]

I did the same thing.


Widely reported problem, and discussed a bunch on this forum and the other one. The timing of the interference seems to coincide with the release of the larger Wilwood pedal arms. Makes sense. You basically have two options. Relief on the pedal arm (e.g. remove material) or relief on the 3/4 inch tube. I wouldn't think of going back to the old pedal arms, since they were changed because of reported breakage. On my Mk4 with the same issue, I chose the 3/4 inch tube. Even though people way smarter than me say it's structurally sound to remove some material from the clutch arm, I'm just not comfortable going that way. If you choose the 3/4 tube for relief, lots of choices. Some have just beat on it with a hammer (not my choice), others have done some really nice fab and welding and put in an angled relief. I don't weld, so I chose to cut the tube, and splice a new piece on the outside. This really isn't the best pic, because it's dark plus everything is powder coated black. But it's the only one I have. If you zoom in on the area in question, you can see the beginning and end of the piece that was added, and where the 3/4 inch tube was cut. The piece that was added is solid, and there are inserts inside the 3/4 inch tube where the bolts go through. Easily as solid as before, but with plenty of clearance.

http://i867.photobucket.com/albums/ab234/edwardb123/Factory%20Five%20Mark%204%20Roadster%20Build/Update%2011212012/IMG_1877.jpg (http://s867.photobucket.com/user/edwardb123/media/Factory%20Five%20Mark%204%20Roadster%20Build/Update%2011212012/IMG_1877.jpg.html)

[David Hodgkins]

David, you have taken quite a bit of meat out of the 3/4" tube - is that going to weaken it? I haven't started my build yet, but I do prefer this idea!

The tube is attached to the footbox fore and aft of that spot and I was told by a popular builder that you can just cut the tube out and there is still plenty of strength. I see the theory but didn't feel comfortable just cutting the whole tube. If you look closely you can see I cut a little less than halfway into the tube, retaining a significant amount of metal there. Lots of folks doing it various ways but I'm very happy with my result.

:)

PS I have more pics in My Anniversary build album (http://thefactoryfiveforum.com/album.php?albumid=825) if you want to browse...

[edwardb]

Off topic, but am I looking at a Wilwood Pedal box with a hydraulic clutch and Hydro-booster power brakes? Referring to pic enclosed by Edward B.

Yes, yes, and yes. That's exactly what you're looking at. From my Mk4 build. More details in the build thread, link in my sig line. The build is done now, legal and driving. All works very well.

[hgcars]

Here is a photo of my fix. This is on a Coupe. 42562

[chopthebass]

I asked Dan at FFR about this and this is his response:


You should have more than adequate clutch pedal travel for engagement/disengagement of the clutch before contacting that tube, so no action is required

[FMJ]

I have to respectfully disagree with Dan that "no action is required". Notch the clutch arm or 1" tube and move on.

-Fred

[edwardb]

I asked Dan at FFR about this and this is his response: You should have more than adequate clutch pedal travel for engagement/disengagement of the clutch before contacting that tube, so no action is required

I too disagree. Every setup is different I guess. I suppose you could adjust the pedal high enough to where it would full disengage the clutch at the interference point. But I look at all three pedals as a unit. Where the accelerator falls, where the brake pedal needs to be to have reasonable heel and toe (even though I'm not a racer I still like it adjusted that way), and then the clutch pedal in the same plane as the brake pedal. When all is said in done, in my experience, it's going to take pushing the clutch pedal all the way to the floor to get the right amount of clutch actuation with the other pedals in the best locations, and it's going to contact the tube. For a hydraulic clutch, I guess you could adjust the cylinder sizes to reduce the clutch pedal required, but then the effort goes up. Mod required, but it's easy however you do it. Lots of things on the build are harder/more complicated than this.

[chopthebass]

Thanks Ed & FMJ. I think I will notch mine at the start of my build. Must be easier to do this before the pedal assembly goes in.

[FMJ]

I painfully didn't realize the issue until it was assembled.

-Fred

[DaleG]

No such issue with #8075; plenty of clearance for clutch pedal travel. Like Edward said: set-ups may vary a bit from car to car?