Hi All,
haven't posted for a while, but have been keeping an eye on the forums last couple of years.

Got a query on the clutch throw out lever arm, retainer spring, rubber boot and fulcrum point in a NP435 trans.
Having a bit of a look at my setup today and noticed that the boot doesn't seem to seat properly in the square opening.
Firstly, does the boot actually assist in holding the lever arm in the correct position? Obviously it's primary design is to keep crud and other stuff out of the clutch housing. Noticed that when the clutch rod was removed, the arm seems to have quite a bit of movement in it. When I assembled it, (new wire spring and rubber boot) seemed to go together as it should, took a bit of fiddling with a screwdriver to get the spring over the little tang at the base of the fulcrum plate.
Showed a torch in the square hole with the boot removed and the wire retaining spring looks to be still in position, but boot doesn't seem to want to seat correctly. Vehicle has not been used for quite some time, wondering if it would help to not only seat the boot, but assist the lever arm from wandering about, if I was to put a bit of adhesive of some description on it. Wouldn't be all that hard to make up a metal plate to secure the boot in it's place, but would have to drill and tap the actual cast iron housing, no real big deal. I should add here that I am NOT using the original hydraulic slave cylinder, but a mechanical rod & linkage setup which PULLS the clutch lever from the back of the transmission. kept the original "Z" bracket and long spring in place to keep the throwout distance as per original, otherwise everything as standard except for the rod which PULLS instead of PUSHES.
There is a raised edge both sides of the boot which should hold it in the correct spot, but it looks like it hasn't been seating properly for a while and has set in it's current position. Anyone know of anything I might be able to soak the rubber boot in to try and get it back into it's original shape? As I said, it was new at the time, but through not being used has hardened up a bit.
Any clues would be appreciated, thanks Dave.

 

The boot is for "dust" only. Has no other function, like holding the fork in position. All my vehicles that boot has been missing for decades. Sounds like your rubber boot is just dried up and shrinking and likely not going to stay properly. Usually they get oil soaked and fall apart.

The fork will always have a flimsy feel to it even installed. That is the play in everything.

You sound like you have the early "bailing ring" style retainer for your clutch fork.






It was replaced later with just a simple clip style:




All it does is snap in a slot of the pivot and holds the fork in place to make it easier to install the transmission. Your early pivot has a tang for the ring to clip onto.

 

Freightrain,
thanks for that, yeah, my fork is the one at the top photo, wire spring setup, Always thought it was a flimsy idea compared to some others.
Does the fork in the bottom photo which has a modified clip, sit on the same fulcrum (or pivot point)??
Not really going to rip the box out just to change the fork unless it becomes absolutely necessary. Can remove my fork without removing the box, lots of jiggling with a torch in one hand, fine pointed screwdriver, hanging upside down with neck at impossible angle etc etc but can be done.
I can see that the clutch rod (with the adjuster on it) and the Z bracket and spring would keep the fork from wandering around, just seems to be a bit of a slack bit of engineering in the first place. Even those ball joint type used in some housings, the ones with the spring clip which closes around the ball, are a better idea than this. But, we live with what we are given. Maybe someone or other has come up with a better idea or design???
Cheers, Dave64

 

Bloke suggested I ask if anyone else has had trouble with this abovementioned issue.
He seems to think that a mob like Lakewood or someone similar came out with an after-market adjustable pivot ball and clutch arm to suit the 1968-1972 F100-F250-F350 that originally had the 300-6 engine.
Come across this type of pivot ball and clutch throwout lever in some Euro or Jap light trucks, seems a much better idea. Once the spring is around the ball it's there to stay, unless the actual spring breaks of course.
Anyone done this simple conversion in the trucks mentioned above?
Thanks, Dave64

 

The clip style arm can NOT be removed from the bellhousing with the transmission installed. The clip goes into a slot on the pivot arm, you have to slide it out of the slot to get it loose and with the throw out bearing installed you can't move it enough. Maybe that is why the change in design?

Here is what the pivot looks like for the other design:



Yours looks more like this:



That little tab is pressed out to attach the bailing wire.


The later model stuff, typically cable pulled clutch, uses a pivot ball on the opposite side of the bell.



You can't get these out without pulling transmission either.

 

Freightrain,
OK, got it! Now all I need to get hold of is a part# for the upgraded fork AND the pedestal it sits on.maybe also a new boot #.
If I can get one sent over here to Oz, if and when I have to separate the trans from the engine I can have it ready to drop in.
many Thanks, Dave64

 

I got my last boot from Dennis Carpenter and it lasted until I put it on. Ripped it up trying to get it on. Was no give/stretch in it. (Was even pre-heated to soften) Just saying..

Dan

 

Sorry, don't have any proper part numbers for you to order them by. Maybe NumberDummy or Jeffafa can help out since they are parts guys and have all the information.

 

There are two clutch levers used 1965/76. But I have no idea if the parts used on Aussie trucks are the same as US/Canadian trucks, because I don't have an Aussie parts catalog.

All I-6 & V8 = 1965/69 F100/350, 1970 F100/350 before serial number G30,001:

C3AZ-7515-C .. Clutch Release Lever / Reproduced by Carpenter
------------------------------------------------------------------------
All I-6 & V8 = 1970 F100/350 from serial number G30,001, 1971/76 F100/350:

D0TZ-7515-A .. Clutch Release Lever / Obsolete ~ 12 available NOS
------------------------------------------------------
C5TZ-7513-A .. Clutch Release Lever Dust Shield / Reproduced by Carpenter

1965/76 F100/350 I-6 & V8; 1977/79 F100/350 300 I-6.

 

Ya, the old right hand drive might put a kink in the works. Wondered why it was hydraulic...now I realize why. The pedals are on the WRONG side LOL. You would think it wasn't anything special.

 

Thanks, Guys
Dave64

 

The C3AZ7515C is the wire style fork. D0TZ7515A is the later style Train was talking about.

And the fork pivot bracket was part number C8AZ7522A. Replaced by C8AZ7522B. Discontinued. But the D0TZ7515A has a divot in it for the rod to PUSH it.

 

Thanks.
Contacted Carpenters, awaiting reply.
Dave64

 

Throw out lever with slot for late model lever:

https://www.holley.com/products/driv...s/parts/RM-150

 

Thank You
Dave64