Need some help figuring out what's going on with my clutch fork

[tribaltalon]

So first of all, this is a NP435 transmission.





We installed a new diaphragm style clutch in it. It previously had a stock appearing clutch and the 3 speed. The clutch linkage is all very janky and i am going to replace alot of it but what concerns me is that the clutch fork feels very "loose" in the bellhousing. i can see it pushing the throwout bearing forward to where it barely contacts the fingers on the clutch, but then its a hard stop and i can't push it any further by hand (pushing on the clutch fork).





thats what i can see in there with the clutch fork pushed as far forward as i can push it. Any help would be greatly appreciated.

 

[B RON CO]

Hi, I don't think you could push the fork by hand to depress the pressure plate. The Z bar gives a mechanical advantage. I don't know if there is a preferred throw out bearing for you. I do know throw out bearings come thick and thin. Hopefully someone who has done this swap will know. As long as the fork is clipped into the bell housing it should be good. There should be a light coat of grease where the throw out bearing slides, and in the pilot bearing. Good luck

 

[tribaltalon]

Yeah I jammed a socket in between the fork and rod and had fiance push the pedal and that's what it is. The rod is so rusted it won't turn so I'm just going to rebuild that whole assembly.

 

[DirtDonk]

So you're saying that you can't push the fork far enough by hand to even get the bearing to contact the fingers? If so, then yeah something is wrong. And not with the linkage, but with either the fork pivot itself (there are two types by the way) or the clutch.

For sure the bell housing is all the way up against the block and the transmission is all the way mated up to the bell housing? That's actually the most common issue with trans installations, but not the fork and bearing not touching the clutch.

Standard Ford truck clutch cover and disc? I wonder if the disc was too thick and causing the fingers of the diaphragm to compress too far when the plate was torqued down to the flywheel?

Good luck.

Paul

 

[AZ73]

I suspect the fingers on your new clutch don't come out as far as your old one. You'll need to adjust the rod that depresses the fork to take up the slack.

 

[B RON CO]

Hi, so you used a socket to lengthen the rod. Now it is time to put it in a vise, soak it, heat it, free it, and you will be able to adjust your clutch. Good luck

 

[tribaltalon]

yeah, i'm going to just order all new components. it is super rusty, stripped, and bent. no bushings anywhere so it's got tons of play. i think once i get all that installed it will be MUCH better. Thanks for the advice guys.

 

[DLB]

I had a similar problem with my GM switching from borg and beck to diaphragm style. If it is the same problem - You'll need a longer throw out bearing otherwise the geometry of your clutch fork will not work. You will be fighting it forever.
Novak conversion has some good info on their site.

 

[Pa PITT]

YES I TOO THOUGHT you need a longer throw out bearing & Of course everthing rust free & a light coat of slick-um so it can all travel . & As I recall I think I put about an inch of adjustment on my clutch rod when I did that swap but that was 10 years ago .

 

[tribaltalon]

well shoot i sure hope that's not it. I'd hate to have to pull this motor or trans/tcase out again to change out throwout bearings. I think an inch or so of additional length on the clutch rod will be plenty good. the small socket i jammed in there only added 3/4 of an inch or so I'd guess and it was almost perfect. Did yall put in longer throwout bearings when you went from lever style to diaphragm clutches?

 

[DirtDonk]

I think most have not. Adjust the linkage, yes of course. You've changed the whole design of the clutch so it's natural to have to compensate in one way or the other. But to have to modify or use different parts? Doesn't seem corect.
The NP is a Ford transmission, fits a Ford bell housing, and has the standard Ford (for that model) input shaft splines and length. Even your stock pilot bearing and throwout bearings are supposed to work.
The same part number throwout bearing was used by Ford up to and after they switched to a diaphragm type clutch themselves. In theory then (gotta love theories!) they should all work together in yours too.
So yes, many have had to tweak their adjustment a little when changing from the Long-style to diaphragm style clutch. But that much? I don't think I've ever heard of that.
Maybe there have been issues but I missed them here? Certainly possible, but it seems it would have come up way more often since pretty much everyone is swapping to the new style these days.

And speaking of diaphragm clutches, where did you get yours and what part number is it? It looks strange to me. Most that I see have a more curved cover shape to them, while yours is more at right angles. Looks odd.
Is this a 10" or 11" clutch and flywheel? Truck originally have a six-cylinder or V8 in it?

Are the bell housing and fork the ones that were working previously? Or have either been changed at this time?
The forks are often a little floppy, but not so much you'd be worried about them. It sounded from your first post though, like you could only get it to barely contact the fingers. Was this with the pedal only, or did you push it by hand?
If you're only using the pedal as-adjusted, then disconnect it and push the fork by hand to see what you get. If it's limited physically then there is something wrong. If it's just limited by the current adjustment then there really is nothing to talk about until you adjust it. As said you've literally changed the entire design of the clutch, so yes you might also have to re-adjust the linkage to suit.

But that is still a bunch of space to take up. If you think the linkage is not adjustable enough, then I say there is still something wrong.
If it's all checking out and you have to adjust it so it reaches an extra inch, then that idea of a longer throwout bearing sounds like a very reasonable solution.
I've just never heard of it being a "thing" until just now. I can be accused of being stuck in my ways and behind the times though!

Paul