Diaphragm clutch and free play

[carfreak6970]

i have a 67 dart with a 383 and a four speed I am working on and I am running into some issues with the clutch fork clearance with the headers.

I have long tube TTI headers that are contacting my clutch fork. I dimpled the headers to the point the fork and rubber isolator doesn’t contact the tube when the fork has the throw out bearing contacting the diaphragm fingers. I also can move it about a quarter of an inch before the rubber insulator will contact the tube. However, when I put the metal washer that rests against the rubber insulator that the lower clutch rod extends through, that metal washer does contact the tube when the throw out bearing is touching the diaphragm fingers. And I have no free play at that point.

I know the FSM says there should be about 3/32’s or so of free play in the clutch adjustment, but that was for a different style clutch than what I have installed. So how much free play would I need for the style clutch I have in there now?

I went with these TTIs because I was told they would work with the four speed (and power steering). But I really have to rework this one tube to get everything to line up.

To hammer the tube I am disconnecting the header from the engine, raising the engine up and tilting the header back so I can get to the area to dimple the tube. Even then I don’t have much room to swing to dimple the header. I am not taking the header out to hammer it because it is more than a pain in the *** to do so without a lift. I am at the point If i have to take the header out to hammer it, something else will go in. I’m that upset about it.

 

[carfreak6970]

Here is it with the metal washer held in place

Here is it with the throw out bearing contacting the diaphragm clutch fingers and the metal washer removed

 

[AJ/FormS]

Get a shorter fork? They come in at least two lengths.
Or a different height pivot bracket.
You may have a wrong-year bellhouse
IIRC the od box only has one height pivot, but the older ones had two, or more.
Visit Brewers
Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists

 

[carfreak6970]

I just got this fork from brewers. This was the only one they listed for a big block a body

The pivot was what the bell housing had when I got the car. The casting number on the bell housing was correct for this vintage big block abody (this is an original 383 4 speed car)

 

[carfreak6970]

Where is the casting number for bell housings? Can I see this while the drive tran is installed in the car?

 

[mopardude318]

Do you have the modified Z-bar available from TTI?

http://www.ttiexhaust.com/MoparClassics-Components/ZB307_detail.jpg

 

[mopardude318]

Whoops, not the z-bar, you have fork issues disregard the above post.

 

[AJ/FormS]

As to the casting number; No the number is on the mounting face between the bell and the trans.
The correct fork pivot will cause the fork to sit near the front of the window with the TO bearing against the PP, and as the fork moves back, it will end up near the back of the window.
The fork you have now is never gonna play nice with that tube in it's current location. I would take the fork out and make sure it is the 10.875 one
CF702 appears to be the correct one for your engine/body style and is supposed to be the 10.875 . Pull yours out and verify the length. Also verify that it is sitting correctly on the TO bearing,which being sliped into the TO bearing clips,fully engaged in the pivot, and properly located in the window.
Or you could just cut that header pipe out of there and move it over.
This is HotRodding 101.
There are a couple of forks to choose from; not all will fit properly in the window. There are straight ones, offset ones ,and about 3 lengths. The one you want is supposed to be 10.875


Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists

 

[carfreak6970]

Thanks for that A/J. I didn’t have the correct fork initially, but the one that is in there now is the CF702 one. I purchase this one a couple months ago.

Here is how the fork sits in the “window” with the TO bearing resting on the clutch fingers

And this is how the fork sits on the TO bearing

 

[carfreak6970]

I believe my bell housing is a casting number 2488372... I got that from a picture I took of the over all painted bell housing, so the a number may be off

 

[AJ/FormS]

I don't see that number (2488372) listed in the Govier book. The closest I see is 2468372, which is listed fo 65/66 bigblock B/C-bodies.
I have no idea what the difference might be.
But Brewers lists this 372 for 67 to 69 A-bodies as well.

Great pictures; excellent work.
Your install looks sorta normal to me; except I think the fork should be parking a lil further forward...... which I think would make your situation even worse No matter if the fork doesn't hit the back of the window when the departure is set up.

But something looks off about that housing; it seems to not look deep enough to me; like the trans is too close to the engine. Lemmee go picture hunting. Nope the windows all seem to appear in about the same place. And the differences appear to be just the rear opening for the different sized retainers, IOW if the retainer fits, then you got the right bell.


2468372

2892513

 

[carfreak6970]

Interesting... thank you for that information.

Yea I think I read the picture wrong. I’ll blow the picture up when I get to work tomorrow and try to confirm what I got.

But I took the fork out and measured it, it’s correct. However, I’m not to sure about that pivot point. See the pictures below

 

[AJ/FormS]

Yeah that looks home made. The factory ones that have seen are stampings. I'm not knocking homemade, I mean that's what HotRodding is.
Furthemore swapping out that bracket to a shorter one will move the fork rearwards and you might run out of window back there, when the clutch pedal is pushed down. Whereas a taller pedestal will move the fork forward harder into the header.
I'm starting to think yur out of options with the fork business, and the only other option is to move the header.
Hang on I just thought of something; those stamped pedestals have a very narrow bearing surface compared to that angle-iron. Maybe install that thing into the fork clip, and see if that all works correctly. Another thing that irks me is if the slot is in the wrong place vertically, that would force the fork into an unnatural position and unknown arc of travel.
FP680; no dimensions given

 

[carfreak6970]

I think it is homemade as well... and one thing I did notice is that even with the fork seated on the fork pivot only one of the fork fingers is resting on TO bearing tab. The other fork finger is not even touching the tab on the TO bearing. Which tells me the pivot point needs to be moved closer to the input shaft of the transmission. Doing so should move the fork away from the tube... However I do not know if that will cause other problems with the associated linkage.

standby.

 

[AJ/FormS]

I think it is homemade as well... and one thing I did notice is that even with the fork seated on the fork pivot only one of the fork fingers is resting on TO bearing tab. The other fork finger is not even touching the tab on the TO bearing. Which tells me the pivot point needs to be moved closer to the input shaft of the transmission. Doing so should move the fork away from the tube... However I do not know if that will cause other problems with the associated linkage.

standby.

I tried to prove that by looking at the pics, but just couldn't.

 

[matthon]

Brewers stuff is spot on to the original.
I replaced my fork, z-bar, etc, and it's all an exact match.

I recently went to an 18 spline and had to trim the bottom z-bar arm, bend the pedal rod a little to line it up, and modify the bell ball bracket.
Yes, I cobbed it by screwing a bolt into it to get home because it slipped, and haven't touched it since. Lock washers didn't work, I meant to sort it more permanent, but I haven't had the time and it ain't broke anymore.
I did remove the zip ties, just put them on as I was paranoid the rod would fall off on my initial test drive.

I have Schumachers and a mini starter, but didn't come close with the 23 spline, same clutch too.

Enough about me, and I'm probably not helping, but if you need me to check something on mine let me know.

Also, the fork does sit low in the window, the big rubber boot is molded that way too.

 

[carfreak6970]

So I was able to purchase the fork pivot from Brewers and got time this past weekend to get it installed. Everything lined up great!

I was able to install part of the clutch linkage but not all of it completely. I needed a third hand to hold the Z-bar Pivot that attaches to the frame as I tightened the nut from the other side. So hopefully next time I will get it all squared away. Thank you all for your help!

 

[AJ/FormS]

Nice work.
If the frame-side Z-bar pivot is not already welded to the sheetmetal, you will likely want to do that, else over time, the stuff will move on you and eventually tear the sheetmetal

 

[carfreak6970]

Nice work.
If the frame-side Z-bar pivot is not already welded to the sheetmetal, you will likely want to do that, else over time, the stuff will move on you and eventually tear the sheetmetal

AJ, the bracket is already welded to the frame (it was originally a 4 speed car), I just need someone to hold the wrench that would be attached to the ball stud that attaches to that bracket while I tighten the nut. My arms are not long enough to tighten the nut while my other arm reaches over the fender and down into the engine bay.