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I have a 1979 F-100 (300 3-on the tree). Tonight I was installing a clutch kit to eliminate a knocking sound I was hearing. I found many problems, throw out bearing, bad pressure plate, bad pilot bearing, and a clutch with no more meat to give. Long story short the cherry on top is that I think my input shaft has been mangled a little too far I will attach photos. What do I do now? Also are these pressure plates interchangeable,the bolt holes line up but the teeth are different. Be blunt and be honest if I need a parts trans I better get looking sooner than later. Any rebuild resources if needed would be much appreciated. For reference you don't have to use your finger nail as a feeler gauge it's obvious with the pad of your finger. I also attached a photo of what a good input shaft looks like on my buddies trans, I just don't know how far gone is too far gone. Plus a bonus photo of the collapsed teeth My input shaft Good input shaft Two pressure plates in question Bad pressure plate
How well does the input fit in the new bearing? it just looks like one insignificant groove. if it's not too loose I'd run with it. the only time it does anything is when you release the clutch, so it can't be sloppy but it doesn't have to be perfect. . This is why I still prefer a quality pilot bushing.
It's just a different style diaphragm clutch. and some of those won't fit some bellhousings without issues, I'm not sure in your case. if it bolts up and clears the bellhousing it should work.
Just a different design where they cut the fingers of the pressure plate, no issue there, is the pilot a bushing or a bearing?
If the knocking sound you heard was with the clutch pedal released, like going down the road or idling in neutral, was maybe the front most bearing in the transmission.
If it was heard with clutch pressed, might been the throw out bearing.
What was the issue with the pressure plate, besides old. How loose was that pilot bushing or bearing on the input shaft. Wondering what chewed on the input shaft anyway. I have seen input shafts welded and reground, but not so sure yours needs that yet.
How does the flywheel look?
I always have the flywheel dressed up while into it this far.
If you do remove the flywheel, when installing, be sure to put locktite on the threads as sometimes oil will creep round threads and ruin your new project. those bolts have access to the oil inside crankcase...
Just somethin to think bout.....
Good to know it should work fine. The pilot has a needle bearing I didn't catch how snuggly it fit into it. When I go back to work on it some more tonight I'll see how slack the new one sits in it. The throw out bearing was bad but I had done a quick swap thinking that was the only problem as the noise was most prominent with the clutch pedal down. It used to be a soft metallic grinding with the pedal up that got amplified when I pushed it down. It definitely got quieter after I switch the throw out bearing but it was still there. Now it has evolved to where it almost sounds like a consistent knock that gets much louder when I depress the pedal. It seems to only knock (or at least prominently knock) once up to temperature though and sometimes it does it less than others, and the knock is only audible from the cab not the engine bay. If you look at the photo of the old pressure plate the teeth were collapsing on it that's what was wrong with it. I thought the only other culprit could be my pilot bearing but if it is internal transmission noise would their be another way to identify it? I wonder if it kept my motor in a state of 90% engaged and messed some things up.
@440 sixpack I'll be going back tonight to do more work will post a photo of flywheel for you guys, and I'll check tolerance with the new needle bearing. When my buddy ordered a clutch kit for his 1970 model f100 he got a three tooth pressure plate with a choice of bearing or bushing, I'm wondering if I could find that part number and install a bushing instead the bushing would have more surface area and the groove wouldn't matter much then right?
With the clutch pedal out, the transmission shaft is turning with the crankshaft, there is no pressure on the throw-out bearing unless it's adjusted too tight. I would smooth any burrs on that shaft end where it contacts the pilot bearing or bushing, depending on which you use. That extra groove looks deadly to bare needles, but might be OK once smoothed out. Really not highly loaded, just keeps the shaft aligned. If the pilot fit is too loose, it could place undue stress on the front bearing in the transmission. Your clutch pressure plate is a diaphragm type, a really large springy cupped washer with slots cut from center out provides pressure, I see you have a few bent fingers as they are called. Your buddy had a three finger pressure plate, they use real springs for pressure, but they are usually stiffer to operate.
Pilot bushing vs bearing, looking at RA for '79 F-100, only shows auto for 300-I-6 ... but if looking at choices for '79 F-150 shows manual & auto options, with choices of pilot bushing or pilot bearing. Shows dimensions too. We used to always use bushings, GTO, Chevelles, Mopars, even my bosses F-350s etc. I don't think I ever even saw a pilot bearing, but that was long ago. Bushing will likely be more forgiving with that input shaft?
I had one transmission have a front bearing start rattling after a several miles long steep uphill grade pulling a trailer at 50 mph in third (was a 5 speed), and I guess the oil was not so deep in the front of the transmission due to the grade, then add in extra engine speed ... and heat and load damaged it. New bearing cured it.
I would ditch the roller bearing and get a bushing. It will be more tolerating of the groove in the shaft, and as an added bonus they are MUCH easier to remove when it comes times to replace the clutch again. I have never had a roller bearing fail to disintegrate when trying to remove it, and then you're in there with a cold chisel trying to break the outer cage without scoring the crank.
A lot of people spin the roller bearing as being "high performance" or more efficient. Unless you have a race car you simply don't need it. For reference, our T56 equipped Camaro and Viper have bushings and two cylinders on those things make more power than a 300. Never had a problem.
Well,, if it was mine I would get a pilot BEARING and slip it on the shaft to be sure it was net too slopy.
Reason for using the bearing instead of the brass bushing is that input is a lettle buggered up.
That to me means that by not being smooth as it should be it will cause more ware on that brass than a smooth shaft would.
With the bearing, the bearing will do the spinning and the shaft should not. (I like bearings) anyway.
Just my old guy logic here..
