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Discussion Starter #21
LuK slave and master kit installed; and let me tell that pedal is SMOOOOOOOOTH!!! and no more horrendous creaking noise!!!
 

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:smile2::smile2:
 

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Discussion Starter #23
well fellas, that feeling in the pedal is coming back; not screeching or anything yet, but definitely can feel a groan in the pedal when releasing the clutch from a stop after the truck has warmed up; does anybody make a heavy duty slave/master kit? All I can find are the cheapo $80 plastic ones from Advance Auto or Autozone. It's only been a 14 months and about 5k miles since it was replaced...
 

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South Bend sells a heavy duty clutch system for just over $200. I’m in the process of replacing my clutch and uppipes but the weather and work aren’t cooperating. The heavy duty system looks well made
 

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Discussion Starter #25

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That’s the one. I don’t know if it’s some sort of plastic or not, it’s still in the box. The one I put on to replace my oem parts was a cast metal, but it blew up when the clutch failed
 

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Discussion Starter #27
hmm ok. I've searched for a few days around different forums to see if they make a heavier duty kit. Seems like the slave/master kit is the weak link on the ZF6. Sounds like the plastic tabs break easily, and in my case, the plastic cylinder gets worn, causing a groove where the push rod binds and makes groaning/screeching noises. So, the cast metal one you speak of, obviously that was an aftermarket kit. Do you know who made it. I'm assuming it failed because the clutch failed...not the unit itself. If you get a chance, would you mind taking a peak at the South Bend kit? Just wondering if it's gonna be worth the extra $150 over the Autozone cheapo replacement. From the pictures, the only difference I can see is that the line is braided steel as opposed to rubber or nylon or whatever the cheapo version uses.
 

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The aftermarket one I had is from O’Reilly auto parts. Took forever to get and was always noisy, like a machine shop when the pedal was pushed. I’ll look at the south bend when I get home Friday
 

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Interesting comments about the slave cylinder problems. I'm at 220k miles on the original on my truck. It's been removed and replaced many times (clutch and tranny changes) and still works as new without noise.
 

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My factory system was much smoother and very quiet, but had gotten enough moisture in it that anytime it got really pushed with a heavy load I had to pump the pedal to get it to work. I got sludge out of it several times trying to keep it, even replaced the brake fluid three times with new fluid from containers I had just opened to eliminate contamination. Always better for a short time then it would get hot and quit. First time I took the slave off to bleed it the grey sludge that came out looked like wet cement and a lot of it
 

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Discussion Starter #31
well I went ahead and ordered the South Bend kit; hopefully this will last longer than a year and 10k miles...I'll let yal know.
 

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My ZF-6 will creak from the slave cylinder. Took me awhile to find it. Only does it when it's warm. Had to have the wife press on the pedal while I was under the truck feeling for it. Been that way for awhile. I have a new pre-bled assembly ready to go in when it dies.
 

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My factory system was much smoother and very quiet, but had gotten enough moisture in it that anytime it got really pushed with a heavy load I had to pump the pedal to get it to work. I got sludge out of it several times trying to keep it, even replaced the brake fluid three times with new fluid from containers I had just opened to eliminate contamination. Always better for a short time then it would get hot and quit. First time I took the slave off to bleed it the grey sludge that came out looked like wet cement and a lot of it
Now I want to go check mine.
 

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Discussion Starter #34
My ZF-6 will creak from the slave cylinder. Took me awhile to find it. Only does it when it's warm. Had to have the wife press on the pedal while I was under the truck feeling for it. Been that way for awhile. I have a new pre-bled assembly ready to go in when it dies.

OK!!!!!! finally!!! sorry that you're having that problem, but that makes me feel better that I'm not the only one with this issue! but yes, definitely slave cylinder that is the issue. The factory setup with metal pushrod finally wore a grove in the plastic slave cylinder, which when warmed up, made a nasty creaking sound. Now, this Autozone cheapo replacement is starting to have the same moan and groan (which will turn into a loud screeching noise) after only 14 months and less than 10k miles. Hopefully this South Bend "heavy duty" kit will fix this permanently...
 

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Do you think if you greased the pushrod that it would prevent the groove from happening?
 

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Sil-Glyde or 3M silicone paste is the slave pushrod grease of choice. I don't know how big a risk but regular grease getting onto the bore of slave (or master too) and getting onto the wall can get to the rubber of the piston and cause it to swell. Silicone sprays are usually 3 drops of silicone and the rest of the can is propellant and inert stuff. SO many of the aerosol lube products will wash away the remainder of what lube paste is there and end up making the problem worse.

Another thing from years of working on these: 7.3 PSD trucks with 6 speeds use that pilot bushing with needle bearing that rides on input shaft. The bearing failure scars the input shaft and a new bearing will fail quickly.
There is a sealed bearing, 6003-crs or 103-cc are some numbers for it in some brands, that fits into flywheel and has an ID for trans shaft that works. if you clean the shaft up. A sealed bearing for pilot is pretty common and I'm surprised they chose the needle bearing which is more problematic on all I have seen it used on. A brass bushing is better than the needle bearing.
The bore of flywheel where the pilot bearing fits is 35mm and the input shaft pilot diameter is 17mm the bearing is 10mm wide but it could be wider if you found the ID/OD the same.. Pilot bearing is not noisy enough to hear it with engine running in many cases. You hve to get truck on an incline, turn off engine, then put it in ger and depress clutch and let it roll. In 1st you will have a high speed at input shaft with rolling speed no faster than a walk. If the growling to squealing noise happens then it narrows it to a small list. Pilot bearing is most likely. A driveshaft support bearing could be noisy but it turns much slower than input shaft in this test. Release bearing (throwout bearing) is not turning when fly wheel isn't turning so that can't be the noise source.
I suspect the 6.0 with ZF-6 also uses this bearing but I have never put a clutch in a 6.0 truck. There are so few of them and the only ones I worked on did not need clutches before the owners got out of them.
 

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I suspect the 6.0 with ZF-6 also uses this bearing but I have never put a clutch in a 6.0 truck. There are so few of them and the only ones I worked on did not need clutches before the owners got out of them.
The input shaft on the ZF-6 for the 6.0L has a larger pilot diameter. Some guys running 7.3L's with the ZF-6 have installed that input shaft and bored out the flywheel to match the larger bearing. Probably done by Ford to fix the problem with the needle style bearing. The issue with it is that the flex section in the disk lets the shaft rotate back and forth just a bit with the clutch engaged in relation to the flywheel and put wear spots in the shaft where the needles sit. The cause is the normal diesel engine rotational vibration of the engine crankshaft.
South Bend Clutch uses a Kevlar bushing in place of the pilot bearing. I've been using them for years, although I did have one wear out. It doesn't take out the input shaft though like a needle bearing would.
 

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Discussion Starter #38
Do you think if you greased the pushrod that it would prevent the groove from happening?

I was planning on just installing the kit as is because it comes prebled and ready to drop in. Although it looks like some other folks have mentioned that lube may not help...may make it worse. Well, hopefully this South Bend kit is truly heavy duty and will last this time.
 

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Sil-Glyde or 3M silicone paste is the slave pushrod grease of choice. I don't know how big a risk but regular grease getting onto the bore of slave (or master too) and getting onto the wall can get to the rubber of the piston and cause it to swell. Silicone sprays are usually 3 drops of silicone and the rest of the can is propellant and inert stuff. SO many of the aerosol lube products will wash away the remainder of what lube paste is there and end up making the problem worse.

Another thing from years of working on these: 7.3 PSD trucks with 6 speeds use that pilot bushing with needle bearing that rides on input shaft. The bearing failure scars the input shaft and a new bearing will fail quickly.
There is a sealed bearing, 6003-crs or 103-cc are some numbers for it in some brands, that fits into flywheel and has an ID for trans shaft that works. if you clean the shaft up. A sealed bearing for pilot is pretty common and I'm surprised they chose the needle bearing which is more problematic on all I have seen it used on. A brass bushing is better than the needle bearing.
The bore of flywheel where the pilot bearing fits is 35mm and the input shaft pilot diameter is 17mm the bearing is 10mm wide but it could be wider if you found the ID/OD the same.. Pilot bearing is not noisy enough to hear it with engine running in many cases. You hve to get truck on an incline, turn off engine, then put it in ger and depress clutch and let it roll. In 1st you will have a high speed at input shaft with rolling speed no faster than a walk. If the growling to squealing noise happens then it narrows it to a small list. Pilot bearing is most likely. A driveshaft support bearing could be noisy but it turns much slower than input shaft in this test. Release bearing (throwout bearing) is not turning when fly wheel isn't turning so that can't be the noise source.
I suspect the 6.0 with ZF-6 also uses this bearing but I have never put a clutch in a 6.0 truck. There are so few of them and the only ones I worked on did not need clutches before the owners got out of them.
Jimmy,

Could you be bit more specific?

Thanks

Only kidding...you knocked this one out of the park.
 

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Discussion Starter #40
ok fellas, I installed the South Bend slave/master cylinder pre-bled kit this weekend. Super easy install. I have noticed however that with this kit, the clutch engages almost immediately. And when I say immediately, I mean as soon as the pedal is about 1/2 inch off the floor, the clutch is engaging. Before it would engage about half way up. Does this mean something is wrong with the pre-bled kit??? Or, just that the clutch is still really new?? Why would this kit make the clutch engage much quicker?? The clutch itself only has about 8k miles on it. It's a LuK clutch.
 
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