Wow you guys are amazing. I don't have the rubber boot around the fork, so it's possible the PO has been in there. Also, I suspect my threaded one-piece rod may not be OEM. I think my zbar is for the one piece rod but the rod in my truck is maybe a homemade replacement (the tip doesn't look right.) As far as the clutch fork being bent, it comes "pre-bent" so I don't know if I'll be able to determine if mine is wonky. The tip of the rod is in alignment with the "pocket." I am able to shift and drive the pickup, but the clutch isn't quite right. If/when I replace the rear seal, I'll probably replace the clutch even if there is some life left in it. I live in ND and winter is upon us with no heated shop for me. So this winter will be gathering information and making a priority list for when the weather breaks in the spring. That being said, my pickup is in the body shop as we speak getting a new windshield! (The body shop is a little out of town and I figured I better bring the pickup to him while it's still driveable!) Thanks so much again guys for the info/knowledge!

 

So the weather has been unseasonably warm (not complaining!) Yesterday was almost 40 and today was only a little cooler so I was able to poke around my clutch a bit. I first had to determine whether or not the adjustment rod was threaded through the block (it is not). Second, I had to free up the block and both locking nuts. Everything was rusted solid, but the block was pivoting. Heat and penetrating oil allowed me to remove the adjustment rod. It measures at 7 3/4" I did not have time to take everything apart, but I am still planning on replacing all bushings, washers, etc. I adjusted the rod to what seems to take up the slack. When I started, the adjusting nuts were to the end. After fiddling around, there is about 1 inch of threads showing at the top. When I had everything apart, there was definitely play in the zbar and release fork. I don't know what acceptable tolerance are. Should the release fork be "solid" other than being able to push it as if the clutch were being applied?

 

The fork just pivots in the bellhousing. the springs are the only things keeping it from rattling around.

Be sure you keep a little slack in the adjustment so the fork isn't riding on the throw out . if the fork feels solid back it off until it has a little play and the throw out clears the pressure plate.

 

I'm deferring to you, 440 (People like you who have adjusted many clutches are so helpful to a guy like me who never has.) When you say "a little slack" and "a little play" how much are we talking? Like 1/4"? More? Less? Thanks so much! (I know I have to install bushings, etc. I want to do this adjustment for experience, to "unrust" everything, and see if my clutch feels any different. I'm saying this because others have told me to replace worn parts BEFORE adjusting the rod.)

 

Once you replace all the worn parts no doubt you'll have to adjust it again. but since it's a 5 minute job do it now too.

The way you're supposed to do it is measure the " free play " in the travel of your pedal. but with old worn stiff parts I prefer to adjust it by the slack in the fork.

The best way is to look in the inspection cover and see what your fork is doing. have it adjusted so when the pedal is untouched the fork is backed away from the throw out enough it's not touching at all. if you can't see it then go by feel. the goal is to get the fork away from the fingers so nothing is touching, but without excess slack that requires more pedal travel . get that done and you're ready to go.

 

Thanks so much! I'm not aware of an "inspection cover" on my T18 bell housing. I will try to look in the clutch fork hole. By the way, my rubber clutch fork boot is not complete. How big of a deal is this? In the meantime, I will back the adjuster rod out of the "pocket" just a touch and then test drive. I will keep you posted!

 

Most bellhousings have a cover but you might not. the boot is just to keep dirt and moisture out , you should replace it but it's not a big deal.

 

Ok so I just went out to start my pickup. I pressed the clutch in and it stayed near the floor. I was able to use my toe to lift the pedal back up. I am going to return the adjusting rod to where it was before to see if it returns to pre-adjustment condition.

 

you have an assist spring under the dash. if your clutch is too far out of adjustment it won't let your pedal pop back up all the way.

 

I put things back the way they were before. Pickup is functional, but clearly there's a problem as maxing out the adjustment made the clutch work. My plan is to custom make a longer adjuster to test effects. I've inspected the zbar. I can't say what condition my zbar bushings are in, but I can't see how worn bushings would effect my clutch in such a way. The fork seems suspect. It moves fairly easily in all directions. From what I understand, I would have to drop the tranny to replace the fork or anything else that might be wrong inside. Before I go that far, I will try the longer adjusting rod. If that helps, I'll replace bushings, felt washer and pivot. Then I'll readjust as necessary.

 

When Z bar bushings are no longer there the bar rides on the pivots and they start to wear.
The part with threads is the motor side pivot on my 81 F100, the frame side was just as bad.


If you look closely at the flat piece the "round" hole is not round. That part is at the clutch pedal that the rod is on going through the floor to the Z bar.
The pivot is NA so I had to fix it by welding, grinding and filing back into shape for the plastic bushing to fit on.


I had 2 through the floor rods and both were bad so I fixed them both, 1 as a spare.


The other parts in the pictures also had to be fixed to get all the play out of the clutch linkage.
You need to pull all that apart and check them because unless they are as bad as mine were you would never see it.

Oh that pivot snapped the threads off moving it around the in & out of the garage.
I fixed it with a bolt I cut the head off and welded it to the pivot, on the first test drive it snapped pulling in the drive.


The next fix I did the bolt deal again but this time I drilled down the center of the bolt & pivot and drove in a roll pin before welding it.




Been good for 5000 mile so far.
Dave ----

 

thanks so much for the pics...very helpful...so basically I have to dismantle the in cab clutch assembly AND the zbar linkage to diagnose? Any comment on the movement of my fork? Thanks again!

 

I'm not sure in your application, but often you can pull the fork out of the bellhousing. it just clips on the throw out, question is do you have the clearance.

You should be able to just push and pull on all the components and tell if you have excessive slack. the Z bar bushings and other pivot points don't have to be real tight but if the slop around they're shot.

A longer rod would probably help. but it's a bandage not a cure , something is out of whack. most likely the geometry is going to start giving you undesirable angles effecting the function if it isn't already.

 

That's the thing, with everything hooked up, things "feel solid" I would hate to remove the fork and not be able to get it back in. Eventually I want this pickup to be a 12 month vehicle, but I won't be driving it much this winter. But I do want it available for when I need it. My plan is to get it functioning well enough until spring and warmer weather comes, then I can fix the clutch system properly. I have to pull the tail housing to replace my speedo drive gear. I also think I have a rear main leak. I don't want have to drop the tranny more than once, nor the drive shaft. So here's how I typically do things make a parts list, including things I "might" need. Once I have all the parts (and the weather is warm enough to work outside) I start the project. But ALWAYS I run into some part that I didn't order. So then with things all apart, I have to wait for the part to continue the project to completion. This is not a frame off restoration. It's a functioning pickup and I hesitate to get so far into things that the pickup is off the road for weeks (or months) at a time. Thanks guys!

 

If things don't feel too bad then they're probably not too bad. I'd look elsewhere.

Confirm your Z bar and your fork are correct. maybe you can find pictures. it's also possible your pressure plate is incorrect . possibly the throw out is incorrect. just because things fit doesn't mean they work correctly, unless you did it yourself always assume someone stupid did it and if you're lucky they weren't.